Art
[1]
The present invention relates to a video signal processing method and apparatus.
BACKGROUND
[2]
Recently, the demand for high-resolution, high-quality video, such as HD (High Definition) video and UHD (Ultra High Definition) video is increasing in various application areas. Since the image data has been increasing the amount of high resolution, high quality is the more relatively data compared to traditional image data if the stored transmit image data using a medium such as an existing wired or wireless broadband, or with a conventional storage medium, transmission cost and It increases storage costs. In order to address these issues as the picture data of high resolution, high quality image can be compressed with high efficiency techniques are utilized.
[3]
A video compression techniques inter picture predicting the pixel values ​​of the current picture from a previous or subsequent picture in the current picture prediction techniques, by using the pixel information in the current picture screen for predicting the pixel values ​​of current picture prediction techniques, It may assign a short code to a value of high appearance frequency, and transmitted or stored until there is a variety of techniques, such as an entropy encoding technique for assigning a long code to the low frequency of appearance values, and effectively compressing the image data by using such a video compression technology.
[4]
On the other hand, with the increased demand for high-definition video, and even with increased demand for stereoscopic content as a new video service. There is ongoing debate about the resolution and second video compression technology to provide a high-resolution stereoscopic content effectively.
Detailed Description of the Invention
SUMMARY
[5]
An object of the present invention is to provide a method and apparatus capable of efficiently performing intra-prediction for a method as coding / decoding a video signal, an encoding / decoding block.
[6]
An object of the present invention is to provide a method and apparatus capable of performing intra prediction for encoding / decoding the current block based on the plurality of reference lines, according as coding / decoding a video signal.
[7]
An object of the present invention is to provide a method and apparatus that can be replaced by a reference sample available a reference for the non-visible according as coding / decoding video signals, it generates a plurality of reference line samples.
[8]
An object of the present invention is to provide a method and apparatus for calculating an average value of either one, of the plurality of reference line as in encoding / decoding a video signal.
[9]
SUMMARY OF THE INVENTION In the present invention are not limited to the technical problem mentioned above, it is not mentioned another technical problem will be clearly understood to those of ordinary skill in the art from the following description It will be.
Problem solving means
[10]
A video signal decoding method and apparatus according to the present invention may lead to a plurality of reference sample line for the current block, out of the plurality of reference sample line and select the reference sample line used for the intra prediction of the current block, the selected by using a reference sample line, it may perform intra prediction of the current block. At this time, the first reference of the plurality of reference sample line sample line, rain see if the sample is contained, the ratio of reference for the sample, the first reference sample line or different from the first reference to the first reference sample line for included in the sample line can be replaced by the available reference sample.
[11]
Video signal coding method and apparatus according to the present invention, leads to a plurality of reference sample line for the current block, out of the plurality of reference sample line and select the reference sample line used for the intra prediction of the current block, the selected by using a reference sample line, it may perform intra prediction of the current block. At this time, the first reference of the plurality of reference sample line sample line, rain see if the sample is contained, the ratio of reference for the sample, the first reference sample line or different from the first reference to the first reference sample line for included in the sample line can be replaced by the available reference sample.
[12]
In the video signal encoding / decoding method and apparatus according to the present invention, the ratio of reference for the sample, the first reference sample line or the first reference for the the one of the available reference samples included in the second reference sample line ratio of the sample and the shortest It may be replaced by the available reference sample which is located in the distance.
[13]
In the video signal encoding / decoding method and apparatus according to the present invention, not less than the distance threshold value from the ratio of reference samples and the first reference available included in the first reference sample line samples, reference samples for the above ratio is, the Article may be replaced by the available reference sample contained in the second reference sample line.
[14]
In the video signal encoding / decoding method and apparatus according to the present invention, the second reference sample line, can have an index larger than the first reference sample line.
[15]
In the video signal encoding / decoding method and apparatus according to the present invention, the prediction samples of the current block may be generated based on the average value of the part of a reference sample contained in the selected reference sample line.
[16]
In the video signal encoding / decoding method and apparatus according to the present invention, the number of reference samples used for calculating the average value of the reference sample includes reference to the selected sample line may be determined by the size of the current block.
[17]
The for the invention briefly summarized above features are merely exemplary of yangsangil detailed description of the invention which will be described later, and are not intended to limit the scope of the invention.
Effects of the Invention
[18]
According to the present invention, efficient intra prediction can be performed for encoding / decoding the current block.
[19]
According to the present invention, it is possible to perform the intra prediction for encoding / decoding the current block based on the plurality of reference lines.
[20]
According to the present invention, the generation ratio of the plurality of reference lines may be replaced by a reference sample available for the reference sample.
[21]
According to the present invention, it is possible to calculate any one of the average value of the plurality of reference lines to perform intra prediction on coding / decoding the current block.
[22]
Effects that can be obtained in the present invention is not limited to the effects mentioned above, are not mentioned other effects can be clearly understood to those of ordinary skill in the art from the following description will be.
Brief Description of the Drawings
[23]
Figure 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
[24]
Figure 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
[25]
Figure 3 illustrates an example of dividing the one embodiment to which the present invention is applied, coded block on the basis of the tree structure (tree structure) in a hierarchical manner.
[26]
Figure 4 is a view showing the partition mode that can be applied to, the coding blocks according to an embodiment to which the present invention is applied.
[27]
5 is based groups in one embodiment the present invention is applied, a video encoder / decoder - shows a kind of a defined intra-prediction mode.
[28]
Figure 6 is one embodiment to which the present invention is applied, showing the type of the extended intra-prediction mode.
[29]
Figure 7 is one embodiment to which the present invention is applied, a flow chart schematically showing the intra-prediction method.
[30]
Figure 8 is an embodiment to which the present invention is applied, on the basis of difference information of the neighboring sample illustrates a method for correcting the predicted samples for the current block.
[31]
Also as an embodiment 9 and 10 to which the present invention is applied, showing the method of correcting the prediction samples based on a predetermined correction filter.
[32]
Figure 11 is one embodiment to which the present invention is applied, showing the range of the reference samples for the intra prediction.
[33]
12 to 14 illustrates an, example of a reference sample filter as one embodiment to which the present invention is applied.
[34]
15 is a diagram, showing a plurality of reference sample line as an embodiment to which the present invention is applied.
[35]
Figure 16 is one embodiment to which the present invention is applied, by using the extended reference line, a flow diagram illustrating a method for performing intra-prediction.
[36]
Figure 17 is one embodiment to which the present invention is applied, a diagram illustrating a plurality of reference lines for a non-square block.
[37]
Figure 18 is a view using the available reference sample located in the shortest distance as an embodiment to which the present invention is applied, the rain reference for the sample, an example that replaces the reference ratio for the sample.
[38]
As an embodiment 19 and 20 to which the present invention is applied, the rain reference samples, and the ratio in accordance with the reference sample and the distance between the available reference samples belong to the same reference line, the location of the available reference sample is determined adaptively for for a view for explaining.
[39]
21 and 22 is a diagram showing the reference sample is used to derive an average value of the reference line as an embodiment to which the present invention is applied.
Mode for the Invention
[40]
The invention will be described in bars, illustrated in the drawings certain embodiments that may have a variety of embodiments can be applied to various changes and detail in the Detailed Description. This, however, is by no means to restrict the invention to the specific embodiments, it is to be understood as embracing all included in the spirit and scope of the present invention changes, equivalents and substitutes. In describing the drawings was used for a similar reference numerals to like elements.
[41]
First, the term of the second, etc., can be used in describing various elements, but the above elements shall not be restricted to the above terms. These terms are only used to distinguish one element from the other. For example, without departing from the scope of the present invention, the first component may be referred to as a second configuration can be named as an element, similar to the first component is also a second component. And / or the term includes any item of the items described concerning the combination or plurality of the plurality of related items disclosed.
[42]
It understood that when one element is described as being "connected" or "coupled" to another element, but may be directly connected or coupled to the other components, may be other element in between It should be. In contrast, when an element is referred to there being "directly connected" to another element or "directly connected", it should be understood that other components in the middle that does not exist.
[43]
The terms used in the present specification are merely used to describe particular embodiments, and are not intended to limit the present invention. Expression in the singular number include a plural forms unless the context clearly indicates otherwise. In this application, the terms "inclusive" or "gajida" terms, such as is that which you want to specify that the features, numbers, steps, actions, components, parts, or one that exists combinations thereof described in the specification, the one or more other features , numbers, steps, actions, components, parts, or the presence or possibility of combinations thereof and are not intended to preclude.
[44]
With reference to the accompanying drawings, it will be described in detail preferred embodiments of the invention. The same reference numerals for the same components on the accompanying drawings and the description redundant with respect to the same elements will be omitted.
[45]
[46]
Figure 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
[47]
1, the image encoding device 100 includes a picture dividing unit 110, a prediction unit (120, 125), the conversion unit 130, a quantization unit 135, a reordering unit 160, an entropy coding unit ( 165), it may include an inverse quantization unit 140, an inverse transformation unit 145, filter unit 150 and memory 155. the
[48]
FIG constituent parts shown in Fig. 1 does not mean that each independently shown to represent another characteristic feature, made of an constituent parts are separate hardware or a software unit in the image encoding apparatus. That is, the respective constituent parts combined addition of convenience, each of the configuration of at least one constituent part that includes the list part two configurations described or made part a configuration, it is possible to perform a divided parts of one configuration addition plurality of configuration functions for each of these one is included in the scope of the present invention configured without departing from the spirit of the present invention, examples of an integrated and separate exemplary embodiment portion.
[49]
In addition, some of the components are not the essential components that perform essential functions in the present invention can only be an optional component to improve the performance. Structure of the present invention can only be implemented to include only the essential component parts to implement the essence of the present invention except for the components that are used to improve performance, including only optional configuration required components except the elements that are only used for better performance It is also included in the scope of the present invention.
[50]
A picture dividing unit 110 can divide an input picture into at least one processing unit. At this time, in units of prediction unit may be: (CU Coding Unit) (Prediction Unit:: PU) may be a, a translation unit (TU Transform Unit) and may be a coding unit. Picture division section 110 into a plurality of coding unit, a prediction unit, and the combination of the transform unit for the one picture and a predetermined reference (for example, a cost function), as a coding unit, a prediction unit and a translation unit, a combination to select it can be encoded in the picture.
[51]
For example, one picture can be divided into a plurality of coding units. Coding in order to divide the unit of encoding in a picture may be used a recursive tree structure, such as a quad tree structure (Quad Tree Structure) by one of the picture or the maximum size of the encoding unit (largest coding unit) to the root which is divided into different coding units unit may be divided to have the child nodes as many as the number of the divided coded unit. In accordance with a predetermined limit that is no longer divided coding unit is a leaf node. That is, if we assume that the square divided only possible for one of the coding unit, a coding unit may be divided into up to four different coding units.
[52]
Hereinafter, embodiments in the coding unit of the present invention may be used to mean a unit for performing the encoding, it can be used to mean a unit for performing the decoding.
[53]
Prediction unit may be divided to have the form of at least one of the square or rectangle of the same size within a coding unit, one of the any of the prediction unit of the divided prediction unit in the coding units prediction of other It may be partitioned to have a unit with a different shape and / or size.
[54]
If not the minimum coding unit when generating a prediction unit which performs intra prediction based on the encoding unit may perform intraprediction not divided into a plurality of NxN prediction unit.
[55]
Prediction unit 120, 125 may comprise an intra predictor 125 to perform the inter-prediction unit 120 and the intra-prediction for performing inter-prediction. For the prediction unit whether to use the inter prediction or decision whether to perform intra prediction, it is possible to determine the specific information (e.g., intra-prediction modes, motion vectors, reference picture, and so on) for each prediction method. At this time, the prediction process unit is performed and the prediction method and the specific process unit to be the content determined may be different. For example, the prediction method and the prediction mode and the like is determined as a prediction unit, for performing prediction may be performed in a conversion unit. Residual values ​​between the generated prediction block and the original block (residuals block) can be input to the converter 130. Further, the prediction mode information used for prediction, and motion vector information which are coded by the entropy coding unit 165 together with the residual value may be delivered decoding groups. When using a specific encoding mode, instead of generating a prediction block by the prediction unit (120, 125), by directly coding the source block it is also possible to transfer the decrypting unit.
[56]
Inter prediction section 120 thus is predicted based on the information of a part of the coding in the current picture is complete, if the current and of the previous picture or a subsequent picture of the picture also at least predicting the prediction unit, based on information in the one picture, It may predict the unit. Inter prediction section 120 may include a reference picture interpolation, motion prediction unit, a motion compensation unit.
[57]
The reference picture interpolation may receive service information from the reference picture memory 155, it generates the pixel information of more than integer pixels in a reference picture. Can be used for luminance pixel, quarter-8-tap interpolation filter (DCT-based Interpolation Filter) in the DCT-based otherwise the filter coefficient to generate the pixel information of the integer pixels in units of pixels or less. For the color difference signals is 1/8 4-tap interpolation filter (DCT-based Interpolation Filter) in the DCT-based having different filter coefficients on a pixel-by-pixel basis to generate the pixel information of integer pixels or less can be used.
[58]
A motion prediction unit may perform motion estimation based on the reference picture in a reference picture interpolation by the interpolation. There are various methods as a way to calculate a motion vector (Full search-based Block Matching Algorithm) FBMA, TSS (Three Step Search), NTS (New Three-Step Search Algorithm) or the like can be used. A motion vector may have a motion vector value of 1/2 or 1/4 pixel units on the basis of the interpolation pixel. The motion predictor by different motion prediction methods to predict the current prediction unit. Motion predicting method in the skip (Skip) method, merge (Merge) method, AMVP (Advanced Motion Vector Prediction) method, such as an intra block copy (Intra Block Copy) method can be used a variety of methods.
[59]
Intra predictor 125 may generate the pixel information of the current prediction unit based on the reference pixel information of neighboring blocks in the current picture. If it is, the neighboring blocks of the prediction unit then blocks the performing inter-prediction, the reference pixel is a pixel which performs the inter-prediction, with reference of the reference pixel contained in the block performing the inter prediction performs intra prediction for the neighboring blocks of pixels It may be replaced by information. In other words, if reference pixels are not available, it may be replaced by at least one reference pixel in the reference pixels available for reference information that is not available pixels.
[60]
In the intra-prediction mode, prediction may have a non-directional mode that does not use the directional information for the performance of the directional prediction mode, the prediction using the reference pixels in accordance with information on a prediction direction. And a mode for predicting the mode and color difference information to predict the luminance information may be different, it is possible to take advantage of the intra-prediction mode information or the prediction luminance signal information used to estimate the brightness information to estimate the color difference information.
[61]
Intra-prediction for a case the same size of the size of the translation unit of the prediction unit when performing the intra prediction, a pixel that exists on the left side of the prediction unit, and the pixel, the prediction unit based on the pixels existing in the top of existing in the upper left the can be performed. But it can be when the size of the prediction unit to perform the intra-prediction size and phase conversion unit, using the reference pixel on the basis of a conversion unit to perform intra prediction. It is also possible to use the intra-prediction using the NxN split only for the minimum coding unit.
[62]
Intra-prediction method may generate a prediction block after applying (Adaptive Intra Smoothing) AIS filter the reference pixels according to the prediction mode. Type of AIS filters that are applied to the reference pixel may be different. The intra-prediction mode of the current prediction unit for performing intra prediction method may be predicted from the intra-prediction mode of the prediction unit existing in the vicinity of the current prediction unit. When prediction a prediction mode of the current prediction unit using the mode information predicted from the surrounding prediction unit, the intra prediction mode is the same when using the predetermined flag information, the current prediction unit and the surrounding prediction unit for the current prediction unit and the surrounding prediction unit a prediction mode and to transmit the same information that, if the can when the prediction mode of the current prediction unit and the peripheral units of different prediction by performing the entropy coding to encode the prediction mode information of the current block.
[63]
In addition, a residual block that contains the prediction section 120, 125 predicted by performing a prediction based on a prediction unit of the unit to the original block of the prediction unit and the difference value of the residual values ​​(Residual) information generated by the can be generated. The generated residual block may be input to the converter 130.
[64]
Conversion unit 130 in the source block and the prediction unit (120, 125) (Discrete Cosine Transform), DCT residual block including residual value (residual) information of the predicted unit generation via, DST (Discrete Sine Transform), KLT and using the same conversion method can be converted. To apply the DCT transform to the residual block, the intra-prediction mode information of the prediction unit used to generate the residual block might seem apply to apply the DST or KLT can be determined based on.
[65]
The quantization unit 135 may quantize the values ​​converted into the frequency domain in a transform unit 130. The Based on the importance of the image or depending on the block quantization coefficient it may be varied. A value calculated by the quantization unit 135 may be provided to the inverse quantization unit 140 and the reordering unit 160.
[66]
Reordering unit 160 may perform the reordering of the coefficient value for the quantized residual values.
[67]
Rearrangement unit 160 may change the form factor of the two-dimensional block by a coefficient scanning method (Coefficient Scanning) in the form of a vector of 1 dimension. For example, the rearrangement unit 160, the zig-zag scanned using a scan (Zig-Zag Scan) method from the DC coefficient to the coefficients of the high frequency region can be changed to a one-dimensional vector format. May be used instead of the horizontal scanning to scan zag scan vertical scan to scan two-dimensional coefficients of the block type in the column direction, the block coefficient of the two-dimensional form in the row direction according to the size of the transformation unit and the intra prediction mode jig. That is, according to the size and the intra-prediction mode of the conversion unit of zig-zag scanning may determine whether, any scanning method of the vertical scan and the horizontal scan will be used.
[68]
The entropy encoding unit 165 may perform entropy-encoding on the basis of the value calculated by the reordering unit 160. The Entropy encoding, for example, exponential Golomb (Exponential Golomb), may be used for various coding methods such as CAVLC (Context-Adaptive Variable Length Coding), CABAC (Context-Adaptive Binary Arithmetic Coding).
[69]
The entropy encoding section 165 rearrangement unit 160 and the prediction unit (120, 125) from the residual value of the coefficient of the coding unit information and block type information, prediction mode information, the division unit information, a prediction unit of information and transmission unit information, motion vector information, and reference frame information, interpolation information, filter information of the block can be encoded in a variety of information.
[70]
The entropy coding unit 165, the entropy encoding may be the coefficients of a coded unit of input in the rearrangement unit 160. The
[71]
The inverse quantization unit 140 and inverse transform unit 145 inverse quantizes the values ​​quantized by the quantization unit 135 and inverse transform the values ​​converted by the conversion unit 130. Residual value (Residual) generated by the inverse quantization unit 140 and inverse transformation unit 145 is the prediction unit restoring combined with the motion estimator, a motion compensator, and intraprediction predicted through parts prediction unit comprises a (120, 125) it is possible to produce a block (block Reconstructed).
[72]
Filter unit 150 may include at least one of a deblocking filter, offset correction, ALF (Adaptive Loop Filter).
[73]
De-blocking filter may be removed and the resulting block distortion due to the interface between the block in the reconstructed picture. To perform a de-blocking can be determined whether or not to apply the deblocking filter to the current block based on pixels included in several rows or columns included in the block in order to determine. For the application of the deblocking filter to the block can be applied in a strong filter (Strong Filter) or a weak filter (Weak Filter) in accordance with the necessary de-blocking filter strength. Also note that when applying the deblocking filter for vertical filtering and horizontal filtering can be done in parallel for processing the horizontal filter and vertical filter.
[74]
Offset compensation unit for performing a de-blocking the image it is possible to correct the offset of the original image in pixels. Offset and then divided into the area of ​​the number of certain of the pixels included in the image to perform the offset correction for the specified picture determines the area to perform the offset considering a method of applying an offset to the area or edge information of each pixel you can use the method of applying.
[75]
(Adaptive Loop Filtering) ALF may be performed on the basis of a comparison of the original picture and the filtered reconstructed image value. Divide the pixels included in the image in a predetermined group can be performed by determining the differential filter as a single filter to be applied to the group for each group. Information relating to whether to apply the ALF is a luminance signal is shaped, and the filter coefficients of the filter to be applied in accordance with the ALF coding unit (Coding Unit, CU) each block can have, to be transmitted by each may vary. Further, the application may be applied to the ALF filter of the same type (fixed type) regardless of the characteristics of the current block.
[76]
Memory 155 may store the reconstructed picture block or output through a filter section 150, the stored recovery block or picture may be provided at the time of performing inter-prediction predictor (120, 125).
[77]
[78]
Figure 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
[79]
2, the video decoder 200, an entropy decoding unit 210, a reordering unit 215, an inverse quantization unit 220, an inversion unit 225, a prediction unit (230, 235), the filter unit ( 240), may be included in the memory 245.
[80]
If the video bit streams from the video encoder input, the input bit stream can be decoded in the process of a video encoder and opposite.
[81]
The entropy decoding unit 210 may perform entropy decoding in the reverse procedure to that performing the entropy coding in the entropy coding unit of the video encoder. For example, it is possible to correspond to the process performed in the video encoder be subject to a variety of methods such as exponential Golomb (Exponential Golomb), CAVLC (Context-Adaptive Variable Length Coding), CABAC (Context-Adaptive Binary Arithmetic Coding).
[82]
The entropy decoding unit 210, the can decrypt the information with regard to intra-prediction and inter-prediction performed in the encoder.
[83]
Reordering unit 215 may perform reordering based on the way rearrange the entropy decoded bitstream in the entropy decoding unit 210 in the encoding unit. The coefficients represented as one-dimensional vector form may be further rearranged to restore it to the coefficients of the blocks in the form of two-dimensional. Reordering unit 215 by the received provided information related to the coefficient scanning performed on the coding unit based on the scanning procedure performed in the encoding unit may perform reordering by a method of scanning in reverse.
[84]
The inverse quantization unit 220 may perform inverse quantization based on the count value of the reordered block and the quantization parameter provided by the encoder.
[85]
Inverse transform unit 225 may be for a conversion that is, DCT, DST, and KLT performed in converting unit for performing a quantization result by the image encoder performs the inverse transformation that is, reverse DCT, reverse DST and inverse KLT. The inverse transform may be performed on the basis of the transmission unit is determined from the video encoder. The inversion unit 225 of the video decoder prediction method, the transformation method (e.g., DCT, DST, KLT) based on the current block of the plurality of information such as the size and direction of prediction can be carried out selectively.
[86]
Predictor (230, 235) may generate a prediction block based on a previously decoded block, or picture information provided by the entropy decoding unit 210, a prediction block generated additional information and the memory 245 provided in the.
[87]
Present on equally to the operation of the video encoder, the size of the size and the conversion unit of the prediction unit of the same when performing the intra prediction, pixel, the upper present in the pixels, the upper left corner existing on the left side of the prediction unit as described above, on the basis of pixels that performs intra-prediction for a prediction unit, however, the case where the size of the transformation unit of the prediction unit for the performance of intra prediction different, using a reference on the basis conversion units of pixels to perform the intra prediction can. It is also possible to use the intra-prediction using the NxN split only for the minimum coding unit.
[88]
Predictor (230, 235) may include predicting unit determining unit, an inter prediction unit and the intra-prediction unit. Prediction unit judging section receives a variety of information such as the motion prediction information of the entropy decoding unit 210, prediction unit information, the intra-prediction method to be input in the prediction mode information and inter-prediction method of the separate prediction unit of the current coding unit, and prediction if the unit is performing inter prediction or it can be determined whether to perform intra prediction. The inter-prediction unit 230 is provided in the video encoder using the information necessary for inter-prediction of the current prediction unit are predicted on the basis of the information contained in the at least one picture of the previous picture or a subsequent picture of a current picture containing the current prediction unit It may perform inter prediction on the unit. It may perform inter-prediction based on the information of the restored partial area - or, a group within a current picture containing the current prediction unit.
[89]
Motion predicting method in the prediction unit included in the coding unit, based on the coding units for performing inter-prediction is a skip mode (Skip Mode), merge mode (Merge mode), AMVP mode (AMVP Mode), the intra-block copy mode of what kind of method can determine whether or not.
[90]
An intra prediction unit 235 may generate a prediction block based on a pixel information in the current picture. When the prediction unit of the prediction unit that performs intra prediction, based on the intra-prediction mode information of the prediction unit provided in the video encoder to perform intra prediction. An intra prediction unit 235 may include a (Adaptive Intra Smoothing) AIS filter, the reference pixel interpolating units, DC filter. AIS filter may be applied to determine whether a filter is applied in accordance with the prediction mode of the current prediction unit as a part that filters the current block of the reference pixel. Using the prediction mode information of the prediction filter and the AIS unit provided in the video encoder may perform the AIS filtering the current block of the reference pixel. If the current mode is a prediction mode of the block does not perform filtering AIS, AIS filter can not be applied.
[91]
Reference pixel interpolation unit may if the prediction mode of the prediction unit of one prediction unit which performs intra prediction based on the pixel value interpolation reference pixels, by interpolating the reference pixel to generate a reference pixel of a pixel unit or less constant value. If the prediction mode of generating a predictive block without the prediction mode of the current prediction unit interpolates the reference pixels a reference pixel can not be interpolated. DC filter has a prediction mode of the current block to generate a prediction block through the filter when the DC mode.
[92]
The reconstructed block or picture may be provided to filter unit 240. Filter unit 240 may include the deblocking filter, offset correction, ALF.
[93]
From the video encoder can be provided with information and di was applied when the blocking filter, information on whether the applied strong filter or apply a weak filter to whether on whether or not applying the deblocking filter to the block or picture. The deblocking filter of a video decoder being provided for the de-blocking filter-related information provided from the video encoder may perform deblocking filtering on the block in the video decoder.
[94]
Offset correcting unit may perform the offset correction on the restored image based on the information such as the type and the offset value of the offset compensation applied to the video encoding operation.
[95]
ALF may be applied to the encoding unit on the basis of whether the ALF application provided from the encoder information, ALF coefficient information, and the like. The ALF information may be provided to include a particular parameter set.
[96]
Memory 245 stores the reconstructed picture blocks or can to be used as a reference picture or a reference block may also provide the reconstructed picture as an output module.
[97]
In the following embodiments, the present invention as described above, used as a term for convenience coding unit (Coding Unit) coding units of description, but the encoding may be not only a unit for performing the decoding.
[98]
Also, the current block, to indicate the coding / decoding the current block, the encoding / accordance with the decoding phase, the coding tree block (or coding tree unit), an encoding block (or encryption unit), the conversion block (or a conversion unit), or prediction block It can be an indication or the like (or the prediction unit).
[99]
[100]
One picture can be divided into the basic blocks of the square or non-square shape encoding / decoding. In this case, the basic blocks may be referred to as the coding tree unit (Coding Tree Unit). Coding tree unit information related to the size of the square or non-square shape and whether or coding tree unit may be signaled through a sequence parameter set, picture parameter set or a slice header and the like. Coding tree unit is divided into a quad tree or a binary tree structure may be the coding unit is produced.
[101]
Figure 3 illustrates an example of dividing the one embodiment to which the present invention is applied, coded block on the basis of the tree structure (tree structure) in a hierarchical manner.
[102]
The input video signal is decoded by a predetermined block unit, the basic unit is referred to as a coded block for decoding Thus the input video signal. Coding block may be a unit for performing the intra / inter-prediction, transformation, quantization. Further, the coding block unit prediction mode is determined (e.g., the intra-prediction mode or the inter-prediction mode), the prediction block included in the coded blocks, it is possible to share the determined prediction mode. Coded block may be a square or non-square blocks of arbitrary size of 8x8 to 64x64 belonging to the range, it can be 128x128, 256x256, or a square or non-square block having a size more.
[103]
Specifically, the coding block can be divided into a hierarchical tree based on at least one of a quad (quad tree) with a binary tree (binary tree). Here, the division of the quad-tree based 2Nx2N block coding scheme is a split of a binary tree-based divided into four NxN coded block may represent a method of coding a block is divided into the two coded blocks. Dividing the binary tree-based may be performed symmetrically, and may be performed asymmetrically. The coded blocks divided by a binary tree-based block may be a square, but may be non-square block such as a rectangular. Dividing the binary tree-based may be performed on a coding block is divided in the quad-tree based it is no longer performed. For the coded blocks divided by a binary tree-based partition of the quad-tree based can no longer be performed.
[104]
Indicating the division of the information, a binary tree based on the size / depth of the quad-tree or a binary tree-based adaptive that this information, quad split tree-based allow for instructing the division of the quad-tree basis to implement the partition coded block for information, a binary tree based on whether the division is the division of information or a binary tree based on the size / depth of the information, a binary tree-based coding block is divided is not permitted for the size / depth of the coded blocks which allow the vertical direction or include information about whether the horizontal direction may be used.
[105]
3, the depth divided (split depth) k is the first coding block 300 may be divided into a plurality of second coding block based on the quad-tree (quad tree). For example, the second coding block 310 to 340 is a square block that has a half size of the width and height of the first coded block, dividing the depth of the second coded block can be increased to k + 1.
[106]
Dividing the depth k + 1 of the second coding block 310 may be divided into a plurality of third code block division depth of k + 2. Second dividing the coding block 310 can be carried out according to the division method by selectively using any one of the quart tree or a binary tree. Here, the division method may be determined based on at least one of information indicating a division of the divided information or a binary tree-based indicative of a quadtree-based.
[107]
The second coding block 310 two quarts case that is divided into a tree-based, the second coding block 310 is divided into four third coded block 310a having a half size of the width and height of the second coded block, the third coded block 310a dividing the depth may be increased to k + 2. On the other hand, in a case that is divided into second coding block 310 is a binary tree based on the second coding block 310 may be divided into two third block coding. At this time, each of the two third coded block is one half the size of the non-square blocks of the width and height of the second coded block, split-depth can be increased to k + 2. The second coded block according to the dividing direction may be determined in a non-square block in the transverse direction or the longitudinal direction, dividing direction may be determined based on information on whether the division of a binary tree-based portrait or landscape orientation.
[108]
On the other hand, the second coding block 310 may be determined by end-coded blocks which are no longer dividing, based on the quad-tree or a binary tree, in this case, the coding block may be used as a predicted block or a transform block.
[109]
Third coding block 310a of the second terminal or determined by the coding block dividing, like the coding block 310 and may be further divided based on the quad-tree or a binary tree.
[110]
On the other hand, the three coded blocks divided by a binary tree-based 310b are further based on a binary tree may be further divided into the coding blocks (310b-2) or a coded block (310b-3) in the horizontal direction in the vertical direction, the coding division depth of the block can be increased to k + 3. Alternatively, the third coded block 310b based on the binary tree further may be determined by non-dividing end-coded block (310b-1), In this case, the coding block (310b-1) can be used as a predicted block or a transform block can. However, the above-described segmentation process allows the division of information or a binary tree based on the size / depth of the information, a binary tree-based coding block is divided is allowed on the size / depth of the coded blocks allowed the division of the quad-tree based on the size / depth of the non-coded block may be performed in a limited based on at least one of information.
[111]
Size of the coding block can have, or are limited to a predetermined number, the size of the unit within the predetermined coding blocks may have a fixed value. For example, the size or the size of the coding block of the picture within the coded block sequences, can be limited to 256x256, 128x128 or 32x32. The information indicating the size of the sequence or the picture within the coding block may be signaled by a sequence header or picture header.
[112]
[113]
Coding block is a skip mode, and is coded using the intra prediction, at least one of the prediction method or inter-picture skipped. If the coding block is determined, it can be divided through the prediction of the coding block to determine the predicted block (Block Prediction). Prediction of the coding block dividing may be performed by a partition mode (Part_mode) showing a split in the form of coded blocks. Size or shape of the prediction block may be determined according to a partition mode of the coded block. For example, the size of the prediction block, which is determined according to the mode partition can have the same or a smaller value as the size of the coding block.
[114]
Figure 4 is a diagram illustrating a partition mode that can be applied to the coded block when the coded block is coded in inter picture prediction.
[115]
If the coding block coded by inter picture prediction, coding block, as shown in the example in shown in Figure 4, any one of eight partitions mode can be applied.
[116]
If the coded blocks are coded with intra picture prediction, the coding block may be subject to a partition mode PART_2Nx2N or PART_NxN.
[117]
PART_NxN is applicable when the coded blocks having the minimum size. Here, the minimum size of the coding block can be defined based on the encoder and decoder. Alternatively, information on the minimum size of the coding block may be signaled through a bitstream. For example, the minimum size of the coding block is signaled through the slice header, and therefore, a minimum size of the coding block can be defined by each slice.
[118]
In general, the size of the prediction block may have a size of from 64x64 4x4. However, if the coded block coded by inter picture prediction, when performing motion compensation, to reduce the memory bandwidth (memory bandwidth), it is possible to prevent the prediction blocks have a 4x4 size.
[119]
[120]
5 is based groups in one embodiment the present invention is applied, a video encoder / decoder - shows a kind of a defined intra-prediction mode.
[121]
Video coder / decoder group may perform intra prediction by using any one of a defined intra-prediction mode. Group for intra-prediction-intra-prediction mode defined may be of a non-directional prediction mode (e.g., Planar mode, DC mode) and 33-directional prediction mode (directional prediction mode).
[122]
Alternatively, the directional prediction modes of a greater number than 33 directional prediction modes can be used to improve the accuracy of intra prediction. That is, it can further subdivide the angle (angle) of the directional prediction mode defines the M number of the extended-directional prediction mode and (M> 33), group-a predetermined angle using at least one of a definition of 33-directional prediction mode It can be used to derive the directional prediction mode with.
[123]
Also it may be used a greater number of intra prediction modes than 35 intra-prediction mode shown in Fig. For example, the more granular the angle of the directional prediction mode, or using at least one of a directional mode of the predetermined number of defined group, it decodes the directional prediction modes with a predetermined angle, a large number of more than 35 intra-prediction mode of You may use the intra-prediction mode. In this case, the use of a greater number than 35 intra-prediction mode of intra prediction modes may be referred to La extended intra-prediction mode.
[124]
Figure 6 is an example of the extended intra-prediction mode, the extended intra-prediction mode may be composed of two non-directional prediction mode, the 65 extended-directional prediction mode. The extended intra-prediction mode may equally be used for the luminance components and the chrominance components, it is also possible to use different numbers of intra prediction modes for each other by each component. For example, the luminance component using the 67 extended intra-prediction mode, the color difference component can be used for intra-prediction mode 35.
[125]
Or, using the intra-prediction mode of a different number, depending on the chrominance format (format) may perform intra prediction. For example, a 4: 2: when the 4 format: performing intra-prediction using a 67 intra-prediction mode in the case of 0 format includes the luminance component and the chrominance component may use the 35 intra prediction modes, 4:04 in all, the luminance components and the color difference component by using the intra-prediction mode 67 intra-prediction may also be used.
[126]
Alternatively, depending on the size and / or shape of the block can each other by using the intra-prediction mode of a different number of performing the intra prediction. That is, using a 35 intra-prediction mode or the intra-prediction mode 67, depending on the size and / or shape of the PU or CU may perform intra prediction. For example, the size of the CU or PU is less than 64x64 or asymmetric partitions if (asymmetric partition) is using the 35 intra prediction modes, and can perform the intra-prediction, the CU or PU size equal to 64x64, or larger case may perform intra prediction by using a 67 intra-prediction mode. In Intra_2Nx2N may allow the 65 intra prediction modes, the Intra_NxN may only be 35 directional intra-prediction mode.
[127]
Sequence, each picture or slice, it may be differently set the size of the block to apply the extended intra-prediction mode. For example, the first slice in the, in the set to be applied to the intra-prediction mode, extended to larger blocks than 64x64 (e.g., CU or PU), the second slice set so that the intra-prediction mode, extended to larger blocks than 32x32 applied can. Information indicating the size of the block in which the extended intra-prediction mode is applied, can be signaled by a sequence, picture or slice units. For example, information indicating the size of which is the extended intra-prediction mode applied to a block may be defined as a 'log2_extended_intra_mode_size_minus4' by subtracting the integer 4 after taking the logarithm of the size of the block. For example, it is the value of log2_extended_intra_mode_size_minus4 is 0, it indicates that it is possible to apply the intra-prediction mode, extended to a block having a larger size than the block or 16x16 with 16x16 or larger, the value of the log2_extended_intra_mode_size_minus4 1, 32x32 or more size a has may indicate that block, or can be applied to the extended intra-prediction mode in a block having a size larger than 32x32.
[128]
In consideration of the above, the color difference component, the color difference format, at least one of size or shape of the block described above, it may be determined if the number of intra-prediction mode. Beyond the described example, the encoding / decoding block to the intra prediction mode, intra prediction mode, which is used to determine which of the candidate (e.g., the number of MPM) on a road, a color difference component, the color difference format, at least one of size or shape of the block It may be determined in accordance with. Reference to the drawings will be described below by using the encoding / decoding method for determining the intra-prediction mode of the target block and the intra-prediction mode is determined, and a look at how to perform intra prediction.
[129]
[130]
Figure 7 is one embodiment to which the present invention is applied, a flow chart schematically showing the intra-prediction method.
[131]
7, it is possible to determine the intra-prediction mode of the current block (S700).
[132]
Specifically, the intra-prediction mode of the current block may be derived based on the candidate list with the index. Here, the candidate list includes a plurality of candidates, a plurality of candidates may be determined based on the intra-prediction mode of peripheral blocks adjacent to the current block. Neighboring blocks may comprise a top of the current block, the lower, the left, at least one of the block located on the right side or corner. The index may specify any one of a plurality of candidates that belong to the candidate list. A candidate specified by the index may be set to the intra-prediction mode of the current block.
[133]
The intra-prediction mode using neighboring blocks in the intra-prediction can be set as a candidate. In addition, the intra-prediction mode of a similar direction and an intra-prediction mode of the surrounding block may be set as a candidate. Here, the intra-prediction mode of a similar orientation may be determined by the value plus or minus the predetermined constant value in the intra-prediction modes in the neighboring blocks. A predetermined constant value may be one, two or more integer.
[134]
The candidate list may further include a default mode. The default mode may include at least one of the planar mode, DC mode, a vertical mode, a horizontal mode. The default mode may be more adaptively in consideration of the maximum number of candidates included in the candidate list for the current block.
[135]
Maximum number of candidates included in the candidate list is 3, 4, 5, may be six or more. Maximum number of candidates included in the candidate list based video encoder / decoder groups-can be a value set a fixed, may be determined as a variable on the basis of the properties of the current block. Property may refer to the location / size / shape, the block is available number / type of intra-prediction mode, the color-difference property, the color difference format of the block. Or, and information indicating the maximum number of candidates included in the candidate list may additionally be ring signal, it may be a maximum number of candidates included in the candidate list to be determined variably by. Information indicating the maximum number of the candidate may be a ring signal from at least one of the sequence level, picture level, slice level or block level.
[136]
Corresponds to the case of the 35 intra prediction modes defined to be selectively used, conversion to the index corresponding to the intra-prediction mode, extended intra-prediction mode of a neighboring block, or 35 intra-prediction mode-extended intra-prediction mode, the group It is converted into an index that can lead to a candidate. Groups to convert the index - may be defined using a table, a scaling operation based on a predetermined value may be used. Here, the group-defined table may be defined by a mapping relation between the intra-prediction modes are different from each other group (e.g., an extended intra prediction mode 35 and the intra-prediction mode).
[137]
For example, using the left neighboring blocks are 35 intra-prediction mode, when the intra-prediction mode 10 (horizontal mode) of the left neighboring blocks, to be converted to an index 16 corresponding to a horizontal mode in the intra-prediction mode, it extended it can.
[138]
Or, using the intra-prediction mode, the upper neighboring blocks extended and, when the intra-prediction mode index of the upper neighboring block of 50 (vertical mode), to convert it to an index 26 corresponding to vertical mode at 35 intra-prediction mode have.
[139]
The above-described intra-prediction mode and for each determination method the luminance components and the chrominance components on the basis of independently be the intra prediction modes derived, the color difference component may be derived in dependence on intra-prediction mode of the luminance component.
[140]
Specifically, the intra-prediction mode of the color difference component may be determined on the basis of the intra-prediction mode of the luminance component as shown in Table 1.
[141]
TABLE 1
Intra_chroma_pred_mode[xCb][yCb] IntraPredModeY[xCb][yCb]
0 26 10 1 X(0<=X<=34)
0 34 0 0 0 0
1 26 34 26 26 26
2 10 10 34 10 10
3 1 1 1 34 1
4 0 26 10 1 X

[142]
In Table 1 intra_chroma_pred_mode means information that is signaled to a specific intra-prediction mode of the color difference components and, IntraPredModeY shows an intra-prediction mode of the luminance component.
[143]
7, a reference sample can be derived for the intra prediction of the current block (S710).
[144]
Specifically, it is possible on the basis of surrounding samples of the current block to derive a reference sample for the intra prediction. Surrounding the sample may be the means that reconstructed samples of the above-mentioned neighboring blocks, which may be restored after the sample of the in-loop filter to the previous reconstructed samples, or in-loop filter is applied has been applied.
[145]
It may be the surrounding sample restore the current block prior to use as a reference sample, a sample close to the filter based on a predetermined intra-filter may be used as a reference sample. To filter out near the sample by using the intra-filter it may also be referred to as reference sample smoothing (smoothing). The intra-filter may include at least one of the second intra-filter applied to a plurality of peripheral sample located in the first intra-filter or the same vertical line that is applied to a plurality of peripheral sample located in the same horizontal line. And either the first filter or the second intra-intra-filter based on the location of the sample is close to be selectively applied, the two intra-filter may be applied redundantly. In this case, the first may be an intra-filter or a second at least one filter coefficient of the intra-filter (1,2,1), but is not limited to this.
[146]
The filtering may be performed adaptively based on at least one of the size of the conversion block of the intra-prediction mode or the current block of the current block. For example, the filter when the intra-prediction mode of the current block, the DC mode, a vertical mode or horizontal mode can not be performed. If the size of the conversion block NxM, filtering may not be performed. Here, N and M may be the same or may be a value different from one another, 4, 8, 16 or any one of more values. For example, when the size of the transform block is 4x4, the filtering may not be performed. Alternatively, a current block of an intra-prediction mode, a vertical mode (or landscape mode) different from the group of - may be based on a comparison result between the (threshold) defined threshold can optionally perform filtering. For example, it is possible to perform the filtering only when the difference between the intra-prediction mode, the vertical mode of the current block is larger than the threshold value. The threshold may be defined by the size of the transform block as shown in Table 2.
[147]
TABLE 2
8x8 transform 16x16 transform 32x32 transform
Threshold 7 1 0

[148]
The intra-filter image encoder / decoder groups group can be determined by any one of a plurality of intra-defined filter candidates. Of a plurality of candidate intra-filter for this purpose there is a separate index that specifies the intra-filter for the current block can be signaled. Alternatively, it is also an intra-filter determined on the basis of at least one of a current block of the size / shape, the change of the information, or close to the sample on the size / shape of the transform block, the filter strength (strength) (variation).
[149]
7, may perform intra prediction by using the intra-prediction mode, the reference samples in the current block (S720).
[150]
That is, by using a reference sample derived from the intra-prediction mode determined at S510 and S500 it is possible to obtain the prediction samples of the current block. However, it can cause poor image quality of the prediction image problem due to use boundary samples in the case of intra prediction adjacent blocks. Thus, with reference to the calibration procedure it may further involve, and, 8 to 10 or less to the predicted samples produced through the prediction process described above will be in view at detail. However, the calibration process will be described later that is not limited to be applied only to the intra prediction sample, the sample can be applied to inter-prediction or reconstructed samples. FIG.
[151]
[152]
Figure 8 is an embodiment to which the present invention is applied, on the basis of difference information of the neighboring sample illustrates a method for correcting the predicted samples for the current block.
[153]
On the basis of difference information of the plurality of surrounding samples for the current block it can be corrected prediction samples of the current block. The correction may be performed for all the samples belonging to the current prediction block may be performed only for the prediction sample that belongs to a predetermined partial area of. Some areas may be one line / ten days in a row / column or more, which group for the compensation in the video coder / decoder - may be a motion area. For example, a plurality of row / column correction can be performed from a boundary of one of the rows / columns or the current block is located at the boundary of the current block. Or, some areas may be determined by a variable based on at least one of the current size / shape or the intra-prediction mode of the block.
[154]
Surrounding the sample may belong to at least one of the neighboring blocks in the upper of the current block, the left side, the upper left corner. The number of neighboring samples used for calibration may be two, three, four or more. Location of nearby samples may be determined variably according to the position of the target within the sample prediction compensation current block. Alternatively, some of the surrounding sample has a fixed position regardless of the position of the prediction target sample the correction, and the other may have a variable position depending on the position of the prediction samples subject to correction.
[155]
Difference information of neighboring samples could mean the difference between the samples around the sample, it may mean a value scaled to the difference samples to a predetermined constant value (e.g., 1, 2, 3, etc.). Here, the predetermined constant value can be determined in consideration of the position of the target compensation prediction samples, the position of the column or row to which it belongs prediction samples subject to correction, the position of the prediction samples in the rows or columns and so on.
[156]
For example, by using a difference between the current sample block of the intra prediction mode is the vertical mode is the case, close to the sample adjacent to the left boundary of the current block p (-1, y) and the upper left around the sample p (-1, -1) then it is possible to obtain a final prediction samples as shown in equation 1.
[157]
[Formula 1]

[158]
For example, by using a difference between the current sample block of the intra prediction mode is the horizontal mode is the case, close to the sample adjacent the upper boundary of the current block p (x, -1) and the upper left around the sample p (-1, -1) then it is possible to obtain a final prediction samples as shown in equation 2.
[159]
[Formula 2]

[160]
For example, by using a difference between the current sample block of the intra prediction mode is the vertical mode is the case, close to the sample adjacent to the left boundary of the current block p (-1, y) and the upper left around the sample p (-1, -1) you can obtain the final prediction samples. At this time, may be added to the difference samples to sample prediction, then scaling the difference samples to a predetermined constant value, it may be adding it to the prediction samples. Predetermined constant values ​​used in scaling can be determined differently according to the columns and / or rows. As an example, then it is possible to correct the prediction samples as in equation (3) and equation (4).
[161]
[Formula 3]

[162]
[Formula 4]

[163]
For example, by using a difference between the current sample block of the intra prediction mode is the horizontal mode is the case, close to the sample adjacent the upper boundary of the current block p (x, -1) and the upper left around the sample p (-1, -1) It may obtain the final prediction sample, which is the same as described above in a vertical mode. As an example, it is possible to correct the prediction samples as shown in Equation 5 and Equation 6.
[164]
[Formula 5]

[165]
[Formula 6]

[166]
[167]
Also as an embodiment 9 and 10 to which the present invention is applied, showing the method of correcting the prediction samples based on a predetermined correction filter.
[168]
Based on the peripheral samples and a predetermined correction filter of the prediction target sample the correction can be corrected prediction samples. At this time, around the sample it can be specified by the current line angle (angular line) of the block-directional prediction modes, and may be one or more samples in the same line and the angle prediction correction target sample. Further, around the sample may be a prediction sample that belongs to the current block, may be reconstructed samples belonging to the neighboring blocks in the current block is restored before.
[169]
The number of taps of the compensation filter, the strength (strength) or the filter coefficients, at least one of whether or not, the angle, the periphery of the intra-prediction mode, the directional prediction mode of the current block if the prediction sample is located at the boundary of the current block is target position, correction of the prediction samples subject to correction prediction mode (inter or intra mode) or the block may be determined based on at least one of the size / shape of the current block.
[170]
9, the at least one prediction / reconstructed samples and the final prediction sample by using a predetermined correction filter is located in the lower left corner of the prediction samples subject to the correction, as is Figure 9, if the one-directional prediction mode index of 2 or 34 It can be obtained. Here, the prediction / reconstructed samples of the left lower end may be belonging to the previous line of the line belonging to the prediction samples subject to correction, which may be part of the same block as the current sample, and may be belonging to the surrounding blocks adjacent to the current block.
[171]
Filtering of the prediction samples may only be performed on-line in the block boundary, and may be performed on a plurality of lines. Each line may have at least one compensation filter is different from the number of taps or filter coefficients of the filters used. For example, for the nearest left of the first line with the block boundary (1 / 2,1 / 2) can be used for filters, it can be used in the case of the second line (12/16, 4/16) filter, and the third line cases (14/16, 2/16), and using a filter, may be used in the case of fourth lines (15/16, 1/16) filter.
[172]
Alternatively, the one directional prediction mode index from 3 to 6, if a value between, or between 30 to 33, it is possible to perform filtering on the block boundary as shown in Figure 10, by using the correction filter of 3-tap to compensate for the prediction sample have. Using the correction of the 3-tap filter to the lower left sample, the lower the sample and the correction target prediction sample at the bottom left of a correction target sample prediction samples as input may perform filtering. Location close to the sample used for the correction filter can be differently determined based on the directional prediction mode. The filter coefficient of the correction filter can be differently determined according to a directional prediction mode.
[173]
If a neighboring block is the inter mode has a different correction filter can be applied depending on whether the intra mode. If the surrounding block in intra mode encoding may be used for filtering to give more weight to the prediction samples than if the coding in inter mode. For example, if the intra-prediction mode 34, when a neighboring block is coded in inter mode, when using a (1 / 2,1 / 2) filter and a neighboring block is coded in intra mode (4/16 , you can use the 12/16) filter.
[174]
Current number of blocks of the line that is within the current block filter in accordance with the size / shape (for example, a coding block, a prediction block) may be different. For example, if the current block size to be the case is less than 32x32 or equal to, the performing the filtering only one line in the block boundary, and otherwise, performs filtering on a plurality of lines, including one line in the block boundary may.
[175]
9 and 10 can be applied in the same / similar in the case of using the described one, the extended intra prediction mode based on the case of using the 35 intra prediction modes that are discussed in FIG.
[176]
[177]
Figure 11 is one embodiment to which the present invention is applied, showing the range of the reference samples for the intra prediction.
[178]
Referring to Figure 11, in reference to the boundary of the current block, the sample P (-1, -1), P (-1, y) (0 <= y <= 2N-1), P (x, -1) ( for 0 <= x <= 2N-1) can be carried out by using the intra-prediction. In this case, all the intra-prediction mode of the current block (e.g., an index of intra-prediction mode, orientation, angle, etc.) or based on at least one of the size of the conversion block of the current block, to selectively perform the filtering for the reference sample can.
[179]
By using the intra-group filter defined in the encoder and decoder may perform the filtering for the reference sample. For example, using the intra-filter filter coefficient (1,2,1) or the intra-filter coefficients (2,3,6,3,2), it can lead to the final reference sample to be used for intra-prediction.
[180]
Alternatively, by selecting at least one of a plurality of candidate intra-filter to perform filtering for the reference sample. Here, the plurality of candidate intra-filter has at least one filter strength, the filter coefficient or the tap (e.g., the number of filter coefficients, the filter length) may be different from each other. A plurality of candidate intra-filter may be defined in a sequence, a picture, a slice, at least one of the block level. That is, the sequences belong to the current block, a picture, a slice, or block can use the same plurality of candidate intra-filter.
[181]
For the following, convenience of description, a plurality of candidate intra-filter includes a first filter and a second intra-intra-filter, the first filter is an intra (1,2,1) 3-tap filter, the second filter is an intra (2,3,6,3,2) assumed to be 5-tap filter.
[182]
When filtering the reference sample by applying the first intra-filter, the filtered reference samples may be derived as the following equation (7).
[183]
[Expression 7]

[184]

[185]

[186]
When filtering the reference sample by applying the second intra-filter, the filtered reference samples may be derived as the following equation (8).
[187]
[Formula 8]

[188]

[189]

[190]
In Equation 7, and 8, x is an integer between 0 and 2N-2, y may be an integer between 0 and 2N-2.
[191]
Alternatively, it is possible to specify any one of a plurality of candidate intra-filter based on the location of the reference samples, and perform the filtering for the reference sample by using this. See, for example, samples that belong to the first range applies to a first intra-filter, and has reference samples belong to the second range may be applied to the second intra-filter. Here, the first range and the second range is, whether close to the boundary of the current block is divided into a reference whether or not, or whether at the top of the current block or or articulated relative to the whether or not the position to the left, close to the corner of the current block whether it can be classified as standard. For example, as shown in FIG. 12, refer to the current block boundary is adjacent to a sample P (-1, -1), P (-1,0), P (-1,1), ... , P (-1, N-1) and P (0, -1), P (1, -1), ... , A first application for intra-filter to perform filtering as shown in Equation 7, that is not currently adjacent to the block boundary, by applying a second intra filter the reference sample, the other equation P (N-1, -1) may perform filtering, such as 8 may select any of a plurality of candidate intra-filter on the basis of the conversion type used in the current block, it performs filtering for the reference sample by using this. Here, the conversion type (1) may refer to a conversion technique such as a DCT, DST, KLT, could mean a (2) 2D transform, 1D conversion, conversion mode indicator, such as non-conversion, (3) primary transformation, it may mean the number of conversion as the second conversion. Hereinafter, conversion type for convenience of explanation, it is assumed to mean a conversion technique such as DCT, DST, KLT.
[192]
For example, if the current block is, if the encoded using a DCT is performed filtering with a first intra-filter, and the current block is coded using the DST, use the second intra-filter to perform filtering have. Or, if the current block is, if the encoded using the DCT or DST is performed filtering with a first intra-filter, and the current block is coded using a KLT, use the second intra-filter to perform filtering have.
[193]
Using the selected filter based on the location of the conversion type and a reference sample of the above-described present block may perform the filtering. For example, if the current block is coded using the DCT, the reference sample P (-1, -1), P (-1,0), P (-1,1), ... , P (-1, N-1) and P (0, -1), P (1, -1), ... , P (N-1, -1) performs filtering using a first filter, intra, and other reference samples may perform filtering using a second filter intra. If the current block is coded using the DST, the reference sample P (-1, -1), P (-1,0), P (-1,1), ... , P (-1, N-1) and P (0, -1), P (1, -1), ... , P (N-1, -1) performs filtering using a second filter, intra, and other reference samples may perform filtering using a first filter intra.
[194]
Reference neighbor block containing the sample conversion type and based on whether or not the same between the present conversion type of the block by selecting any of a plurality of candidate intra-filters, and can use them to perform the filtering for the reference sample. For example, in the case of using the current block and the neighboring blocks have the same conversion type in the case of performing filtering by using a first intra-filter, and the current block and a transform type is different from each other neighboring block has a second intra-filter It can be used to perform the filtering.
[195]
Selecting any one of a plurality of candidate filters on the basis of the intra-type conversion of the neighboring blocks, and can use them to perform the filtering for the reference sample. That is, in consideration of the type of transformation belonging the reference sample block may select the desired filter. For example, as shown in Figure 13, the current block and the block adjacent to the left / bottom left is coded block by using the DCT, the upper / block adjacent to the upper right is the case of the coding block using a DST, left / reference sample adjacent to the left lower part by applying a first reference filter intra performing the filtering, and adjacent the top / upper right samples may perform filtering by applying a second intra filter.
[196]
With a predetermined area unit, the filter available for the zone may be defined. Here, the predetermined area unit of a sequence, a picture, a slice, a block group (e. G., Coding tree unit row), the blocks (e.g., coding tree unit) may be any one of, share one or more filter a separate region may be defined. Reference sample may be filtered using a filter that blocks the current map to the region belongs.
[197]
For example, it is possible, as illustrated in Figure 14, with a different filter to the CTU unit to perform the filtering for the reference sample. In this case, the sequence in the parameter set (SPS) or picture parameter set (PPS), has the sequence or the information indicating whether the picture is to use the same filter, the type of filter used for each CTU, the available intra filter the CTU of candidate there is an index that specifies a filter or the like used can be signaled.
[198]
The above-described intra-filter may be applied to the encoding unit basis. For example, for the reference sample of the surrounding coding unit, the first may be applied to an intra-filter or a second intra filter performs the filtering.
[199]
[200]
When the intra-prediction mode of the current block is determined using a reference sample adjacent to the current block, it is possible to perform intra prediction. For example, the predicted samples for the current block, or generated by averaging the reference sample, can be generated by copying the reference sample, taking into account the direction of the intra-prediction mode in a particular direction. Above, as discussed in the example through 11, P (-1, -1) in the boundary of the current block, P (-1, y) (0 <= y <= 2N-1), P (x, -1) (0 <= x <= 2N-1) this can be used as a reference sample.
[201]
If the sample contained in the adjacent block adjacent to the current block is not judged to be used as a reference sample, can be replaced by a reference sample of available samples are not available. For example, if the location of a sample contained in the neighboring blocks present on the outside of the picture, the case that the sample contained in the neighboring blocks exists in the current block and the other slice the samples contained in or adjacent blocks in the inter-prediction coding block in, for example, when contained in, it may be determined that the neighboring samples that can not be used as a reference sample. At this time, if a sample contained in a block coded in inter-prediction whether rain yonghan is, based on the information indicating whether to use the sample contained in the intra-prediction when the inter-prediction coding block of the current block as a reference sample, is determined It can be. Here, the information can not be a one-bit flag (e.g., 'constrained_intra_prediction_flag'), but is not limited thereto. For example, if the 'constrained_intra_prediction_flag' is 1, the sample contained in a block coded by inter prediction may be determined to not be used as a reference sample. The sample is not available in the following, reference samples, and will be referred to as reference sample for the ratio.
[202]
In the example shown in Figure 11, the sample located at the bottom left (for example, P (-1, 2N-1)) if it is determined that this is not available, then the first reference is found available as the scanning of the available samples into a predetermined sequence by using a sample, it is possible to replace the sample located at the bottom left. Here, the scan order is from samples adjacent to the left bottom sample can be carried out sequentially. For example, in the example shown in Figure 11, the sample P (-1,2N-1), P (-1,2N-2) from P (-1, -1), if a non-soluble, P (-1 in this order, 0) to P (2N-1, -1) may be carried out a scan. P (-1,2N-1) may be replaced by the first available reference samples detected results of scans performed.
[203]
If left yonghan the left reference sample except the reference samples in the lowest ratio, the left reference sample may be replaced by a reference sample adjacent to the left, see the bottom of the sample. For example, P reference for the ratio between (-1,2N-1) and P (-1, -1) sample P (-1, y) can be substituted for the reference samples (P-1, y + 1) have.
[204]
If the upper reference sample ratio yonghan, see above sample it can be replaced by a reference sample adjacent to the upper left reference sample. One erotic, P reference for the ratio between the (0, -1) and P (2N-1, -1) sample P (x, -1) can be replaced with a reference sample P (x-1, -1) .
[205]
Reference sample sets for the current block may be referred to as 'reference line' (or, "intra reference line" or "reference sample line"). Here, the reference line may comprise a single row and a single column reference sample set constructed. For example, in the example shown in Figure 11, the "reference line" is, P (-1,2N-1) from P (-1, -1), P (0, -1) from P (2N-2, 1) may represent a set of reference samples comprising a. Intra prediction of the current block may be performed on the basis of the reference samples contained in the reference line. Intra prediction samples of the current block, may, be performed using a reference sample comprising a reference line in accordance with the intra-prediction mode of the current block. For example, it is possible if the intra-prediction mode of the current block, DC mode, by using the average and the weighted prediction contained in the reference line to generate a prediction signal. For example, when the intra-prediction mode of the current block, DC mode, the prediction samples of the current block may be obtained according to the following equation (9).
[206]
[Formula 9]

[207]

[208]

[209]
In Equation 9, dcVal is, the one of the reference samples with the reference line may be generated based on the average value of the samples, except for P (-1, -1).
[210]
Planar mode does not have a strong edge (edge) represents the effective prediction efficiency in the soft region, it is effective in improving the image quality deterioration of a discontinuity or a block boundary of the block boundaries. If the current intra-prediction mode, the planar mode of the block, the horizontal pre-predicted samples for the current block is obtained using a reference sample having the same y-coordinate and the reference samples and the horizontal preliminary prediction sample close to the upper right corner of the current block and, vertically preliminary prediction samples of the current block, may be obtained using a reference sample having the same x coordinates and the reference sample and the vertical pre-prediction sample close to the lower left corner of the current block. For example, the horizontal direction and the vertical direction prediction sample pre preliminary prediction samples of the current block may be obtained by the following equation (10).
[211]
[Equation 10]

[212]

[213]
Prediction samples of the current block, may be generated by shifting (shifting) by a value which is determined in accordance with the horizontal preliminary prediction samples and the vertical pre-combined after the prediction sample, this current block size. For example, the predicted samples for the current block may be obtained by the following equation (11).
[214]
[Equation 11]

[215]
Intra prediction of the current block may be performed by using a plurality of reference lines. When the current block is assumed to have a size WxH, k-th reference line, p (-k, -k), p (-k, -k) and a reference line which is located in the same sample (for example, p (-k + 1, -k) from p (W + H + 2 (k-1), - k) or reference sample p (-k + 1, -k) from p (2W + 2 (k-1) to, -k) refer to the samples) and p (-k, -k) to the reference position to the same column a sample (for example, p (-k, -k + 1) from p (-k, + H + W 2 (k -1)) or reference sample p (refer to -k, -k + 1) from p (-k, 2H + 2 (k-1)) to the may include a sample).
[216]
15 is a view illustrating a plurality of reference sample line. As with the example in shown in Figure 15, when the first reference line adjacent to a boundary of the current block have been referred to as "reference line 0 ', k-th reference line may be arranged adjacent to the k-1 th reference line.
[217]
Or, in contrast to that shown in Figure 15, it is also possible to configure all the reference line is to have a reference sample of the same number.
[218]
Intra prediction of the current block may be performed by at least one of the plurality of reference lines. Thus, by using a plurality of reference line may be a method of performing intra-prediction, it referred to as "intra prediction method using the extended reference sample (Extended reference intra prediction)" or "extended intra-prediction method." Further, a plurality of reference lines, can be referred to as' extended reference line.
[219]
Whether using the extended reference line whether to perform intra prediction may be determined on the basis of information that is signaled via the bitstream. In this case, the information may be a one-bit flag, and the like. Information as to whether to use the extended reference line whether to perform intra prediction, may be signaled to the coding tree unit, a coding unit or units prediction unit, and may be signaled to the sequence, picture or slice units. That is, whether to use the extended reference line whether to perform intra prediction may be determined in a sequence, picture, slice, CTU, CU or PU unit.
[220]
Or, if using a reference expansion line whether to perform intra prediction may be determined based on the current block size, shape, depth, or at least one of the intra-prediction mode.
[221]
When using the extended reference line determined by performing the intra prediction, the number of the reference line can be determined. At this time, the number of the reference line may have a fixed value may be determined adaptively according to the current block size, shape, or the intra-prediction mode. If for example, the case of the current intra-prediction mode, the non-directional mode of the block while performing the current block is an intra prediction using a single reference line, the intra-prediction mode of the current block the directional mode, using a plurality of reference line and it may perform intra prediction of the current block.
[222]
As another example, the number of reference lines may be determined by the information signaled to the sequence, picture, slice, or decoding target unit basis. Here, the decoded unit unit, may refer to the coding tree unit, a coding unit, prediction conversion unit or units. For example, the syntax elements 'max_intra_line_idx_minus2' representing the number of possible reference line used in sequence or slice may be signaled by a sequence header or a slice header. In this case, it can be set to the number of reference lines are available for max_intra_line_idx_minus2 + 2.
[223]
Or less, by using an extended reference line, will be described in detail how to perform intra prediction.
[224]
16 is using, the extended reference line according to the present invention, a flow diagram illustrating a method for performing intra-prediction.
[225]
First, the decoder may generate a plurality of reference lines (S1610). References included in each reference line samples, may be generated based on the recovered sample contained in the decoded block above the current block.
[226]
If the intra-prediction mode of the current block the directional mode, the decoder may considering directionality for intra-prediction mode, generating a reference line. Depending on taking into account the direction of the intra-prediction mode, k-th reference line may include a larger number of reference samples of more than k-1 th reference line. That is, the farther away from the reference line from the current block may include a greater number of reference samples closer to the reference line and the current block.
[227]
At this time, according to the k-1 number of second reference line compared to the reference k-th reference line including the current block is added to the sample size, shape or the intra-prediction mode, it may be determined in a variable.
[228]
For example, when the current block has a 4x4 size, k-th reference line k-1-th four more reference lines (specifically, in the horizontal direction into two and vertical 2) further includes a reference sample of can. On the other hand, if the current block has a 8x8 size, k-th reference line 8 than the k-1 th reference line (specifically, in a horizontal direction 4 by 4 and the vertical direction) may further comprise a reference sample of have.
[229]
In Figure 15, in accordance with being a current block size of 4x4, the first reference sample comprises a total of 9 reference sample, the second reference sample was seen to include a total of 13 reference samples (9 + 2x2).
[230]
If the current block is non-square, the number of reference sample comprising a reference line can be determined in accordance with the horizontal and vertical length of a current block.
[231]
For example, Figure 17 is a diagram illustrating a plurality of reference lines for a non-square block. Referring to Figure 15 and comparison to Figure 17, in the eight the number of upper reference sample, except for the upper left reference samples, containing the reference line 0 as the current block is reduced to 1/2 of the width, illustrated as four, down It was.
[232]
That is, according to Figs. 15 and 17, assuming that the current block has a size WxH, k-th reference line, W + H + 2 (k-1) of the top of the reference sample (or 2W + 2 (k- 1) of the upper reference sample) (that is, the horizontal direction reference samples), see W + H + 2 (k-1) of the left sample (or, 2H + 2 (k-1) of the left reference sample) (that is, the vertical direction reference sample) and total 2 {(W + H) +2 (k-1)}, such as the upper left reference sample may comprise a + one reference sample.
[233]
If it contains a non-reference sample used for the reference line, the reference sample can not be used can be replaced with a reference sample of peripheral soluble. At this time, the reference ratio is close to replace the reference sample for the samples, and the ratio may be in the same reference line and the reference samples, it may also be included in the ratio of reference samples with different reference lines.
[234]
For example, when using the expanded reference line for performing the intra prediction, the positions of the reference sample or the outside of the picture, if it exists in the current block and another slice or reference samples are included in the encoding to an inter prediction block If, reference sample can be determined that the ratio yonghan. Reference sample when the reference sample contained in a block coded in inter-prediction rain yonghan is, if it is set not to use a reference sample contained in a block coded in inter-prediction, for example, may be limited when the constrained_intra_prediction_flag 1 have. Or, if the case is set to a block coded in the intra-prediction decoding than the first inter-prediction encoding by block, when decoding the block coded in the intra-prediction, the block coded in the inter prediction is not yet a restored state. Accordingly, the reference contained in the block are encoded in the inter-prediction sample can be determined that the ratio yonghan.
[235]
Reference ratio which is used to replace the reference sample for the sample can be determined in consideration of the distance between the ratio of the reference position of the sample, the ratio for the reference sample and the reference samples available. For example, the ratio for the sample is, the ratio can be replaced by the available sample in the sample and the minimum distance for. That is, between the ratio of reference samples and the reference available in the same reference line samples, and the ratio reference distance between the sample (first offset), and non-referenced soluble in the sample and different from the reference line reference for the sample and the ratio reference for the sample for distance compared to the (second offset), may refer to a sample ratio of available reference sample a short distance to the ratio of the alternate reference sample for.
[236]
In the example shown in Figure 18, including a reference line and the reference for the ratio contained in the 0 sample and reference, see the available contained in line zero, the distance between the sample 4 and the reference line reference for a ratio contained in the 0 sample and the reference line 2 the shown as the distance between the two reference samples available. Consequently, it is possible using the available reference sample comprising a reference line 2, to replace the reference sample for the ratio is included in the reference line 0.
[237]
If, the first offset and the second offset if the same, it is possible to refer to ratio of the sample and the reference sample for the replacement ratio by using the available reference samples in the same line for a reference.
[238]
Only if at least the ratio distance between the reference sample and the reference an available part of the same reference line sample and the ratio of reference for the sample (i.e., a first offset) is N for, ratio of use of the available reference samples belong to the reference samples with different reference lines the ratio may be substituted for the reference sample. Or, even in the case at least one offset is N, the second offset is only when smaller than the first offset, may be the ratio to the ratio replace the reference samples using the available reference samples belong to the reference samples with different reference lines . Here, N may represent an integer of 1 or more.
[239]
When the first offset is not equal to or greater than N, the ratio may refer to a sample and using the available reference sample containing the same reference line to replace the reference ratio for the sample.
[240]
If 19 and 20 N is 2, the ratio shows an example that replaces the reference samples as a reference sample available. As with the example in shown in Figure 19, in case the distance between the available reference sample containing the ratio of reference samples and the reference line 0 for containing a reference line 0, 2, by using the available reference sample comprising a reference line 1 , the ratio contained in the reference line 0 can replace the reference samples.
[241]
On the other hand, as with the example in shown in 20, in case of the distance between the available reference sample containing the ratio of reference samples and the reference line 0 for containing a reference line 0 1, the available reference sample comprising a reference line 0 utilized, it is possible to replace the reference sample for the ratio is included in the reference line 0.
[242]
Reference ratio for the sample, the ratio could be replaced by using the available reference sample or reference ratio which the sample is contained in the reference line and the adjoining reference line includes available for reference samples with the same reference line and the reference samples. Here, the reference line and the ratio of the adjacent reference line including the reference samples, the index difference between the ratio of the reference line for the reference sample was included may refer to one of the reference lines. Alternatively, the ratio of using the reference sample has a reference line and an index difference with the reference line included in two or more available reference samples may be the ratio to replace the reference samples.
[243]
Alternatively, the ratio is used to refer to a sample index value greater than the reference line of reference than the reference line, the index value is larger or the ratio lines includes containing the reference sample for this is included in the small reference line available reference samples, a reference sample for the ratio It may be replaced. For example, when the ratio reference sample is used to include the reference line, the index value is greater than for the reference line, the ratio by using a reference sample on the left side or the top of the reference samples, the ratio may be substituted for the reference sample.
[244]
Search of the available reference samples for rain to replace the reference samples can be performed in the previously defined direction. For example, the ratio can be used to replace the reference sample at the top of the sample for the ratio of the, bottom, left, or any of the references in the direction of the sample only the samples for the ratio of the right part of the same reference line and the reference samples. Alternatively, the ratio may be used to replace the reference sample is different from the top of the reference sample for the samples contained in the ratio of the reference line, bottom, left, or any of the references in the direction of the sample only for the ratio of the sample for the right.
[245]
Decoder, can decrypt the index information indicating one of a plurality of reference lines from the bit stream (S1620). For example, as shown in the example shown in Figure 15, when the four possible reference line utilization state index information, it is possible to specify any of the four reference line.
[246]
A reference line for performing the intra prediction for the current block, the current block size, the type of the current block, the current block of the intra prediction mode, between the index information or the current block is an intra-prediction mode, the predetermined intra prediction modes in the neighboring blocks and it may be determined adaptively based on the difference or the like.
[247]
If any of the determination of a plurality of reference line, decoder using the determined reference line may perform intra prediction of the current block (S1630).
[248]
For example, when the intra-prediction mode of the current block, the DC mode, the predicted samples for the current block, may be generated based on the mean value (dcVal) of reference samples contained in the reference line is determined. FIG 21 and FIG 22, will be described in detail for what it calculates an average value of reference sample comprising a reference line.
[249]
Or, may be generated based on the case of the intra-prediction mode of the current block the directional mode, the prediction samples of the current block is specified by reference to the directional mode of the reference sample containing the determined reference sample line. At this time, the prediction if the sample is from a line segment extends toward the direction in which the directional mode pointing points between the reference samples and prediction samples of the current block is a first reference located on each side of the extended line toward the direction in which the directional mode pointing pointing point sample and a weighted sum of the second reference samples may be generated on the basis of the (weighted prediction).
[250]
[251]
If the intra-prediction mode of the current block, the DC mode, it is necessary to average (dcVal) of reference samples belong to, the reference line for performing the prediction for the current block. At this time, the average value of the reference sample of the k-th reference line, can be calculated using only some of the reference samples belong to the k-th reference line. At this time, the number of reference samples used to derive the mean may be the same for each reference line, may be different for each reference line.
[252]
Alternatively, the average value of the reference sample of the k-th reference line, and may be acquired by using all of the reference samples belong to the k-th reference line. Alternatively, the induction averaged using all of the reference samples of the current block size, shape, or depending on the position of the reference line, whether to drive the average using only a portion of the reference sample of the k-th reference line or the k-th reference line It is what may be determined.
[253]
21 is a view illustrating the reference sample is used to derive an average value of the reference line.
[254]
The example shown in Figure 21, using any of a reference sample that belongs to the reference line indicates an example of a reference sample derived average value of the k-th reference line. For example, in the example shown in Figure 21, the reference sample average value of the first reference line (a reference line 0 in Fig. 21) adjacent to the current block, except for the reference sample adjacent to the upper left corner of the current block, see above sample and can be calculated with the left reference sample. That is, when the size of the current block is NxN, a total of 4N number of reference samples and left two upper reference sample 2N reference sample 2N dog or the like can be used to calculate the average value of the first reference line.
[255]
The number of reference samples used for the reference samples the average value calculation of the k-th reference line and may have a value equal to the number of the reference sample used for the reference samples the average value calculated in the first reference line. At this time, the position of the reference samples used to calculate the average value of the k-th reference line, may correspond to a position of a reference sample which is used to calculate the reference sample average value of the first reference line.
[256]
The first reference of the k-th reference line corresponding to the reference samples of the reference line samples, and may have the same x coordinate or the same y-coordinate and reference samples for a reference line. For example, the top of the reference included in the first reference line sample P reference (i, j) top included in the k-th reference line corresponding to the sample, P (i, j) and P (i having the same x coordinate, j-k + 1) may be. For example, the first reference left includes the reference line sample P reference (i, j) the left side of the k-th reference line corresponding to the sample, P (having the same y coordinate, and P (i, j) i-k + 1, j) may be.
[257]
21 shows, the second to fourth reference samples of the reference line corresponding to the top of the reference samples and the reference samples left of the reference line are illustrated. Reference samples of each reference line the average value may be calculated using the reference sample shown in FIG.
[258]
In Figure 21, but it assumes that the current block is a square, it is possible, as an example applied to the embodiment, even if the current block is non-square. For example, when the current block is a non-square block with a WxH size reference for each reference line the sample average value is to be calculated using a total of 2 (W + H) one, such as the top of the reference sample 2W and one sample 2H left reference dog can. Accordingly, as shown in the example in shown in Figure 22, the number of reference samples used for mean value calculation of the k-th reference line may have a value equal to the number of reference samples used for mean value calculation of the first reference line. The position of the reference samples used to calculate the average value of the k-th reference line, the first may correspond to a position of a reference sample which is used to calculate the average value of the reference sample 1, the reference line.
[259]
In Figs. 21 and 22, the left reference sample of 2 multiple of the current block and the top of the reference sample height of the second multiple of the width of the current block has been described as being used to calculate the reference sample average value of the reference line. It is not limited to the described example, than those shown in Fig. 21 and 22, further using a fewer or a greater number of reference samples, a reference sample can also be calculated average value of the reference line. For example, by using a reference sample and the top left reference sample of the same number as the current height of the block equal to the width of the current block, the reference sample may be calculated average value of the reference line.
[260]
Reference samples of the reference line average value, depending on the type and the reference sample position for the current block can be calculated by assigning different weights for each reference sample. For example, if the current block is a square, given the same weight at the top of the reference samples and the left reference sample, reference sample, we can calculate the average value. On the other hand, it is possible, if the current block is non-square, given a higher weight than the other to any one of the top left reference sample or reference sample to calculate the average reference sample. For example, if the current height is greater than the width of the form block, it is possible to calculate an average value for a given weight than the top of the reference samples left reference sample. On the other hand, may form when the width is greater than the height of the current block, for a given weight to the left side than the upper reference sample reference sample to calculate the average value.
[261]
For example, when a current block size of N / 2xN, dcVal average value of the k-th reference line may be calculated by the following equation (12) of.
[262]
[Equation 12]

[263]
For example, when the current block size of NxN / 2, the average value of the k-th dcVal reference line may be calculated by the following equation (13) of.
[264]
[Equation 13]

[265]
In Equation 12 and 13, k may be set to a value between 1 and max_intra_line_idx_minus2 + 2.
[266]
[267]
In the embodiment described with reference to Figure 16, exemplified by then generating a plurality of reference lines, decoding the index information indicating one of a plurality of reference lines. Unlike the above example, it is possible to obtain a plurality of reference lines of any of the back of decoding a particular index information, only the reference line specified by the index information of the plurality of reference lines.
[268]
In the embodiment described with reference to Figure 16, was described as using a particular one of the reference line by the index information of the plurality of reference lines, it performs the intra prediction of the current block. Unlike the above example, the intra-prediction for the current block, may be carried out using more than one of the plurality of reference lines. Whether in performing the intra prediction of the current block, whether to use more than one reference line, the information signaled from the bitstream, the current block size, the type of the current block, the intra-prediction mode, the intra prediction of the current block of the current block if a non-directional mode, or whether it be determined based on the difference between the current block is an intra-prediction mode, the predetermined intra prediction modes.
[269]
Two or more reference lines, it can be specified by a plurality of index information that is signaled from the bitstream. For example, if it is set to use the two reference lines, one of the two reference lines is specified by the first index information, and the other may be specified by the second index information.
[270]
Alternatively, two or more reference lines may be spatially continuous in position. In this case, index information for specifying any one of two or more reference lines to be signaled via the bitstream. When any one of more than one reference line is selected by the index information based on the spatial proximity of the selected reference line, the remaining reference line can be automatically selected. For example, if it is set to use the two reference lines, the index information points to a "reference line 0 ', the intra prediction of the current block, may be carried out on the basis of the reference line 1 adjacent the reference line 0 and the reference line 0 have.
[271]
If it is set to use a plurality of reference lines, can be carried out based on the average value, maximum value, minimum value, or a weighted sum of the reference sample containing the intra prediction of the current block is a plural reference line.
[272]
For example, in the intra-prediction mode of the current block the directional mode (that is, angular (Angular) mode) assumed to be, the prediction samples of the current block, the first reference sample and the second reference included in each different reference line sample It may be generated based. Here, the second reference line including the first reference line and the second reference sample 1 containing the reference sample is not the first reference line and a second reference line, but can be located next to each other, like. In addition, the first reference sample and the second reference sample, can be determined by the intra-prediction mode of the current block. A first reference sample and the second reference sample is also adjacent, but not necessarily so. Prediction samples of the current block is the liquid may be generated on the first reference sample and taken into account in the weighted sum of the first reference sample, the first reference sample and a may be generated based on the mean value, minimum value or maximum value of the second reference sample .
[273]
Intra prediction of the current block, may be performing a first intra-prediction based on a portion of the plurality of reference lines, performed by the basis of the rest of performing a second intra-prediction. In this case, the first intra prediction mode to be used during intra-prediction mode and a second intra-prediction is used when the intra prediction may be the same or may be different. Prediction samples of the current block, the first may be generated based on a second prediction samples produced in accordance with the first prediction sample and a second performing the intra prediction generated in accordance with carrying out the intra-prediction.
[274]
[275]
The above-described embodiment has been described about the decoding process, the same as the order or in reverse order coding process thereof can be carried out as described.
[276]
The above-described embodiments, but is described on the basis of a series of steps or flow chart, which is not necessarily limited to a time-series order of the invention, it may be performed as needed at the same time or performed in a different order. Further, the components that make up the block diagram in the above-described embodiment (e.g., the units, modules, etc.) each of which may be implemented as a hardware device or software, as a hardware device or software in combination with a plurality of components It may be implemented. The described embodiments are implemented in the form of program instructions that may be performed through various computer components may be written in a computer-readable recording medium. The computer readable recording media may also include, alone or in combination with the program instructions, data files, data structures, and the like. Examples of the computer readable recording medium, such as hard disks, floppy disks, and magnetic tape media, CD-ROM, such as an optical recording medium, flop tikeol disk (floptical disk) such as DVD magneto-optical medium (magneto-optical storing program instructions, such as media), and ROM, RAM, flash memory, hardware devices that are specially configured to, perform. The hardware devices may be configured to act as one or more software modules in order to perform the process according to the invention, and vice versa.
Industrial Applicability
[277]
The present invention can be applied to electronic devices capable of encoding / decoding an image.

Claims
[Claim 1]
If the currently deriving a plurality of reference sample line for the block, in the plurality of reference of claim in the sample line reference one sample line, the ratio including the reference samples, the ratio of reference samples, wherein the first reference sample line for or wherein the first reference sample line being different from the first replaced by the soluble reference sample contained in the second reference sample line; Comprising: a plurality of reference samples of the reference sample line select line is used for the intra prediction of the current block; And, the image decoding method comprising the step of using the selected reference sample line, performs intra prediction of the current block.
[Claim 2]
The method of claim 1, wherein the ratio of reference for the sample, the first reference sample line or the second alternative to the available reference sample which is located in the second reference samples referenced available included in the line reference for the the one of the sample ratio of the sample and the shortest distance the image decoding method, characterized in, that the.
[Claim 3]
The method of claim 1, wherein the ratio of reference samples and the first not less than the distance threshold value from the available reference sample comprises a first reference sample line, the reference for the ratio of the sample, the available included in the second reference sample line for to be replaced by a reference sample, it characterized in, the image decoding method.
[Claim 4]
The method of claim 3, wherein the second reference sample line is, the image decoding method characterized by having the first index larger than the first reference sample line.
[Claim 5]
The method of claim 1, wherein the prediction samples of the current block, the reference method to be generated in the sample based on the average value of the part of which is characterized, for decoding an image included in the selected reference sample line.
[Claim 6]
The method of claim 5, wherein the number of reference samples used for calculating the average value of the reference sample includes reference to the selected sample line, the image decoding method characterized in that it is determined by the size of the current block.
[Claim 7]
If the currently deriving a plurality of reference sample line for the block, in the plurality of reference of claim in the sample line reference one sample line, the ratio including the reference samples, the ratio of reference samples, wherein the first reference sample line for or wherein the first reference sample line being different from the first replaced by the soluble reference sample contained in the second reference sample line; Comprising: a plurality of reference samples of the reference sample line select line is used for the intra prediction of the current block; And, the image encoding method comprising the step of using the selected reference sample line, performs intra prediction of the current block.
[Claim 8]
The method of claim 7, wherein the ratio of reference for the sample, the first reference sample line or the second alternative to the available reference sample which is located in the second reference samples referenced available included in the line reference for the the one of the sample ratio of the sample and the shortest distance image coding method, it characterized in, that the.
[Claim 9]
The method of claim 7, wherein not less than the distance threshold value from the ratio of reference samples and the first reference available included in the first reference sample line samples, the reference for the ratio of the sample, the available included in the second reference sample line to be replaced by a reference sample, it characterized in, the image encoding method.
[Claim 10]
10. The method of claim 9, wherein the second reference sample line is, the image encoding method characterized by having the first index larger than the first reference sample line.
[Claim 11]
The method of claim 7, wherein the prediction samples of the current block, the reference being produced by the sample based on the average value of some of the features, the image encoding method comprising the selected reference sample line.
[Claim 12]
12. The method of claim 11, wherein the number of reference samples used for calculating the average value of the reference sample includes reference to the selected sample line, the image encoding method, characterized in that, which is determined by the size of the current block.
[Claim 13]
Inducing a plurality of reference sample line for the current block, out of the plurality of reference sample line select the reference sample line used for the intra prediction of the current block, and using the selected reference sample line of the current block comprising an intra-prediction for performing the intra prediction, and, when the plurality of reference of claim in the sample line reference one sample line, the ratio including the reference samples, reference samples for the above ratio is, the first reference sample line or the first 1 reference sample line different from the first, characterized in that the available references that are replaced by a sample contained in the second reference sample line, the image decoding apparatus.
[Claim 14]
Inducing a plurality of reference sample line for the current block, out of the plurality of reference sample line select the reference sample line used for the intra prediction of the current block, and using the selected reference sample line of the current block comprising an intra-prediction for performing the intra prediction, and, when the plurality of reference of claim in the sample line reference one sample line, the ratio including the reference samples, reference samples for the above ratio is, the first reference sample line or the first 1 reference sample line different from the first, characterized in that the available references that are replaced by a sample contained in the second reference sample line, the image encoding apparatus.