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 for performing intra-prediction by the weighted prediction using the plurality of reference samples, as in encoding / decoding a video signal.
[7]
An object of the present invention is to provide a method and apparatus for using the correction, the predicted sample offset generated by the intra prediction as in encoding / decoding a video signal.
[8]
An object of the present invention is to provide a method and apparatus which uses a different, but offset correction using the offset to the predicted sample generated by performing intra prediction according as coding / decoding a video signal, a predetermined unit.
[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, to determine the intra-prediction mode of the current block, and to derive a reference sample from a neighboring sample of the current block based on the intra-prediction mode and the reference sample, the current it is possible to obtain a first prediction samples for the block, the first and determines the offset for the first prediction sample, obtain a second prediction sample by applying the offset to the first sample prediction.
[11]
Video signal coding method and apparatus according to the present invention, to determine the intra-prediction mode of the current block, and to derive a reference sample from a neighboring sample of the current block based on the intra-prediction mode and the reference sample, the current it is possible to obtain a first prediction samples for the block, the first and determines the offset for the first prediction sample, obtain a second prediction sample by applying the offset to the first sample prediction.
[12]
Whether or not in the video signal encoding / decoding method and apparatus according to the present invention, whether to apply the offset to the first prediction sample can be determined on the basis of the intra prediction mode of the current block.
[13]
In the video signal encoding / decoding method and apparatus according to the present invention, the offset may be determined based on the weighted sum of the multiple reference samples.
[14]
In the video signal encoding / decoding method and apparatus according to the present invention, the weight applied to the plurality of reference samples each can be determined based on the distance to the first prediction samples.
[15]
In the video signal encoding / decoding method and apparatus according to the present invention, the plurality of reference samples, may comprise a reference sample and reference is dependent on the determined position of the first sample of the prediction samples a fixed position.
[16]
In the video signal encoding / decoding method and apparatus according to the present invention, the reference to a fixed position samples, the currently includes a reference sample adjacent to the upper left corner of the block, dependent determined by the position of the first prediction sample referenced samples, the first may include at least one of the first reference is placed on the same vertical line and the prediction sample and the reference sample or the first prediction sample is placed on the same horizontal line sample.
[17]
In the video signal encoding / decoding method and apparatus according to the present invention, each of the plurality of reference samples may be included in different reference lines.
[18]
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
[19]
According to the present invention, efficient intra prediction can be performed for encoding / decoding the current block.
[20]
According to the invention, it may perform intra prediction on the basis of the weighted prediction using the plurality of reference samples.
[21]
According to the present invention, by correcting the predicted samples generated by the intra prediction it has the advantage to improve the encoding / decoding efficiency.
[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 of the partition form of the invention is in one embodiment, the partitioning of the binary tree-based allowed to be applied.
[27]
Figure 5 is a view showing one embodiment to which the present invention is applied, for example, only a particular form of binary tree-based partition allowed.
[28]
Figure 6 is one embodiment to which the present invention is applied, a view for explaining an example in which the information relating to the division number allows a binary tree to be encoded / decoded.
[29]
7 is a view according to an embodiment to which the present invention is applied, illustrating a partition mode that can be applied to the coded block.
[30]
8 is a group according to an embodiment to which the present invention is applied, a video coder / decoder groups - shows a kind of definition of an intra-prediction mode.
[31]
Figure 9 is one embodiment to which the present invention is applied, showing the type of the extended intra-prediction mode.
[32]
Figure 10 is one embodiment to which the present invention is applied, a flow chart schematically showing the intra-prediction method.
[33]
Figure 11 is one 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.
[34]
Also as an embodiment 12 and 13 to which the present invention is applied, showing the method of correcting the prediction samples based on a predetermined correction filter.
[35]
Figure 14 is one embodiment to which the present invention is applied, showing the range of the reference samples for the intra prediction.
[36]
15 is a view illustrating a plurality of reference sample line.
[37]
16 is a flow chart illustrating a method for correcting the predicted samples in accordance with one embodiment of the present invention.
[38]
17 is a flow chart showing a method for correcting the prediction image, the sub-block unit according to an embodiment of the present invention.
[39]
18 to 22 is one embodiment to which the present invention is applied, shows an example of the intra prediction of the current block pattern.
[40]
23 and 24 is a view showing an example in which a different offset for each within a predetermined unit of a sub-block applied.
[41]
25 is a flowchart illustrating a process for obtaining a residual sample in one embodiment where the present invention is applied.
Mode for the Invention
[42]
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.
[43]
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.
[44]
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.
[45]
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.
[46]
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.
[47]
[48]
Figure 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
[49]
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
[50]
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.
[51]
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.
[52]
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.
[53]
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.
[54]
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.
[55]
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.
[56]
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.
[57]
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.
[58]
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.
[59]
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.
[60]
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.
[61]
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.
[62]
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.
[63]
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.
[64]
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.
[65]
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.
[66]
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.
[67]
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.
[68]
Reordering unit 160 may perform the reordering of the coefficient value for the quantized residual values.
[69]
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.
[70]
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).
[71]
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.
[72]
The entropy coding unit 165, the entropy encoding may be the coefficients of a coded unit of input in the rearrangement unit 160. The
[73]
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).
[74]
Filter unit 150 may include at least one of a deblocking filter, offset correction, ALF (Adaptive Loop Filter).
[75]
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.
[76]
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.
[77]
(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.
[78]
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).
[79]
[80]
Figure 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
[81]
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.
[82]
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.
[83]
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).
[84]
The entropy decoding unit 210, the can decrypt the information with regard to intra-prediction and inter-prediction performed in the encoder.
[85]
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.
[86]
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.
[87]
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.
[88]
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.
[89]
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.
[90]
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.
[91]
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.
[92]
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.
[93]
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.
[94]
The reconstructed block or picture may be provided to filter unit 240. Filter unit 240 may include the deblocking filter, offset correction, ALF.
[95]
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.
[96]
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.
[97]
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.
[98]
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.
[99]
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.
[100]
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).
[101]
[102]
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 may be defined as the largest size allowed by the encoding unit sequence or a slice. 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 may be divided into a smaller size for the partition. In this case, if the generated partition tree by splitting a coding unit as to the depth 1, the partitions created by dividing the depth of 1 partitions can be defined as the depth 2. That is, by dividing the generated within the depth k of the partition tree coding unit partition may be defined as having a depth k + 1.
[103]
Coding tree unit may be defined as a coding unit for partitioning the generated arbitrary size as the split. The coding unit is divided or recursively, may be divided into a basic unit for performing a predictive, quantized, transformation, or in-loop filtering, and the like. For example, any size of the partition generated as the coding units is split may be defined or the coding unit, defined as the predicted, quantized, transformation, or the basic unit of conversion unit or a prediction unit for performing such loop filter.
[104]
Partitioning of the coding tree unit or a coding unit, a vertical line may be performed based on at least one of (Vertical Line) or horizontal (Horizontal Line). In addition, the number of vertical and horizontal lines that partition the coding tree unit or a coding unit may be at least at least one. For example, as a vertical line, or one with a horizontal line, the coding tree unit or dividing the coding unit into two partitions, or two vertical and two by a horizontal line, the three partitions the coding tree units or coding unit It can be split. Or, by using a single vertical line and one horizontal line, it is possible to divide the coding tree units or coding unit to the four partitions of the length and width of one-half.
[105]
If the coding tree units or coding unit by using at least one vertical or at least one horizontal line is divided into a plurality of partitions, the partitions may have a uniform size, or may have a different size. Alternatively, it may also be any one of the partitions have a different size from the rest of the partition.
[106]
In the embodiments to be described hereinafter, the coding tree units or coding unit is assumed to be divided into a quad tree or a binary tree structure. However, it can also be further divided in the coding tree units or coding unit by using a large number of vertical line or a larger number of horizontal lines of the.
[107]
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.
[108]
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.
[109]
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. Although the division of a binary tree-based were carried out, in the lower depths may be present in the square in the coding block.
[110]
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. For example, as shown in the example in shown in Figure 4 the partition shape which the division of a binary tree-based allow, symmetric (symmetric) of 2NxN (horizontal non-square coding unit) or Nx2N (vertically non room coding unit), an asymmetric of the type (asymmetric) in nLx2N, nRx2N, 2NxnU 2NxnD or it may include at least one.
[111]
Division of the binary tree-based and may be limited to allow only one of a symmetric or asymmetric form of partition. In this case, it is for constituting the coding tree unit, a square block for the quadtree partitioning CU, configure coding tree unit, in a non-symmetric square block may correspond to a binary tree partitioning. What constitutes a tree-coding unit in a square block with symmetric non-square block may correspond to a quad, and a binary tree CU partitioning.
[112]
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.
[113]
Further, division of sub-depth may be determined dependent on the division form of the parent depths. If a one embodiment, the partitioning of the binary tree based on more than one depth allows, only a binary tree split and forms the same type of binary tree-based partition of the upper depth, this can be tolerated at lower depths. For example, if the binary tree based on the parent depths to form 2NxN division is carried out, even in the lower depth of the division of a binary tree-based 2NxN form can be carried out. Or, in the case of a binary tree-based Nx2N to form in the upper division depth is carried out, even in the lower depth of the division of a binary tree-based Nx2N shape can be allowed.
[114]
On the other hand, it is also possible to allow at lower depths, only a binary tree split and form different types of binary tree-based partition of the upper depth.
[115]
For a sequence, a slice, the coding tree unit or a coding unit, may be limited to only a particular form of binary tree-based partitioning is used. For example, it is possible to limit the allowed 2NxN or only division of a binary tree-based Nx2N form for coding tree unit. Partition type may be acceptable to code the information about the partition type that encoder or decoded groups may be defined based, not allowed, or allowed to form partition signaling on the bit stream.
[116]
5 is a view showing an example in which only a particular form of binary tree-based partition allowed. Figure 5 (a) represents an example that only a limited partitioning of the binary tree based Nx2N This allows, also (b) the 5 shows an example that only a limited partitioning of the binary tree based 2NxN This allowed. 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.
[117]
Further, a coding tree unit or for a given coding unit, a binary tree, the number of times the division is permitted, a binary tree split, such as the number of depth or a binary tree, the split allows the depth is allowed to be obtained. The information may be transmitted via the group decoding, the bitstream is coded in the coding tree unit or units of the coding unit.
[118]
For example, it is through the bit stream, the syntax 'max_binary_depth_idx_minus1' represents the maximum depth that a binary tree segmentation is allowed to be coded / decoded through the bit stream. In this case, max_binary_depth_idx_minus1 + 1 may point to a maximum depth which is a binary tree split allowed.
[119]
Referring to Figure 6, in the example illustrated, shown as a in Fig. 6, a binary tree split for the depth 2 encoding unit 3 and the depth of the coding units performed. Accordingly, the coding tree unit in the binary tree splitting is carried out a number of times (twice), representing the information, the coding tree unit in the binary tree splitting the maximum allowed depth information or coding tree unit indicating (depth 3) in the binary tree split the number of acceptable depth at least one of information indicating (2, depth 2, depth and 3) can be encoded / decoded by the bitstream.
[120]
As another example, a binary tree split is allowable number of times, at least one of the number of the binary tree or a binary tree split the depth segmentation is allowed to be acceptable depth may be obtained by sequence slice. For example, the information, is encoded in a sequence, picture or slice units may be transmitted on a bit stream. Accordingly, it is possible to the first slice and the second slice, a binary tree split count, a binary tree split, at least one of the number of maximum depth or a binary tree depth is divided allowed allowed disparity. For example, in the first slice, while the one which is allowed only in a binary tree split depth, the second slice, a binary tree split can be tolerated in the two depths.
[121]
In yet another example one slice or picture time the level identifier (TemporalID) in accordance with a binary tree split the permitted number, the binary tree segmentation is allowed depth or a binary tree split is acceptable may differently set at least one of a number of depth that is to be the have. Here, the time the level identifier (TemporalID), the point (view), the space (spatial), time (temporal) or the image quality (quality) of the at least one scalability (Scalability) for identifying a plurality of layers each image having a will be.
[122]
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.
[123]
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.
[124]
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.
[125]
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.
[126]
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.
[127]
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.
[128]
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.
[129]
Division result based on the quad-tree and tree-by battery, the coding unit may ttil a rectangle or square of any size.
[130]
[131]
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.
[132]
7 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.
[133]
If the coding block coded by inter picture prediction, coding block, as shown in the example in shown in Figure 7, any of the eight partition mode can be applied.
[134]
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.
[135]
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.
[136]
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.
[137]
[138]
8 is a group according to an embodiment to which the present invention is applied, a video coder / decoder groups - shows a kind of definition of an intra-prediction mode.
[139]
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).
[140]
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.
[141]
35 the larger number of intra prediction modes than the intra-prediction mode shown in Figure 8 may be used. 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.
[142]
9 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.
[143]
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.
[144]
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.
[145]
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.
[146]
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.
[147]
[148]
Figure 10 is one embodiment to which the present invention is applied, a flow chart schematically showing the intra-prediction method.
[149]
Exhibiting a strong directivity may improve the coding / decoding efficiency, by applying the intra-prediction image or the like that is included in the block appear in the embedded block or a previous frame image.
[150]
10, it is possible to determine the intra-prediction mode of the current block (S1000).
[151]
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.
[152]
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.
[153]
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.
[154]
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.
[155]
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).
[156]
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.
[157]
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.
[158]
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.
[159]
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.
[160]
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

[161]
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.
[162]
10, may derive the reference sample for the intra prediction of the current block (S1010).
[163]
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.
[164]
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.
[165]
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.
[166]
TABLE 2
8x8 transform 16x16 transform 32x32 transform
Threshold 7 1 0

[167]
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).
[168]
10, may perform intra prediction by using the intra-prediction mode, the reference samples in the current block (S1020).
[169]
That is, by using the intra-prediction mode and a reference sample derived from a determined in S1010 S1000 may 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 11 to 13 below for generating the predicted sample using 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.
[170]
[171]
Figure 11 is one 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.
[172]
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.
[173]
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.
[174]
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.
[175]
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.
[176]
[Formula 1]

[177]
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.
[178]
[Formula 2]

[179]
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).
[180]
[Formula 3]

[181]
[Formula 4]

[182]
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.
[183]
[Formula 5]

[184]
[Formula 6]

[185]
[186]
Also as an embodiment 12 and 13 to which the present invention is applied, showing the method of correcting the prediction samples based on a predetermined correction filter.
[187]
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.
[188]
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.
[189]
12, 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 correction as shown In Figure 12, 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.

Claims

[Claim 1]Determining an intra prediction mode of the current block; Deriving a reference sample from the neighboring samples of the current block; Determining, based on the intra-prediction mode and the reference sample, to obtain a first predicted samples for the current block; Determining an offset for the first prediction samples; And, an image decoding method comprising: obtaining a second prediction sample by applying the offset to the first sample prediction.
[Claim 2]
The method of claim 1 wherein, the image decoding method, characterized in that in the first prediction samples to whether to apply the offset is determined on the basis of the intra prediction mode of the current block.
[Claim 3]
The method of claim 1, wherein the offset is, the image decoding method characterized in that it is determined based on the weighted sum of the multiple reference samples.
[Claim 4]
The method of claim 3, wherein the weight applied to each of the plurality of reference samples, the image decoding method according to claim, that is determined based on the distance to the first prediction samples.
[Claim 5]
4. The method of claim 3 wherein the plurality of reference samples, reference samples in a fixed position and, the image decoding method comprising: a reference sample to be determined dependent on the position of the first prediction samples.
[Claim 6]
The method of claim 5, wherein the reference to a fixed position sample, reference sample in which the comprises a reference sample adjacent to the upper left corner of the current block and the dependent determined by the position of the first prediction samples, the first prediction sample and the reference sample placed on the same horizontal line or the first prediction sample and comprises at least one of the reference sample placed on the same vertical line, the image decoding method.
[Claim 7]
The method of claim 3, wherein, the image decoding method, each of said plurality of reference sample is characterized in that included in the different reference lines.
[Claim 8]
Determining an intra prediction mode of the current block; Deriving a reference sample from the neighboring samples of the current block; Determining, based on the intra-prediction mode and the reference sample, to obtain a first predicted samples for the current block; Determining an offset for the first prediction samples; And, the image encoding method comprising the step of obtaining a second prediction sample by applying the offset to the first sample prediction.
[Claim 9]
The method of claim 8, wherein the first whether to apply the offset to the predicted sample, the image encoding method, characterized in that it is determined on the basis of the intra prediction mode of the current block.
[Claim 10]
9. The method of claim 8 wherein the offset is, the image encoding method, characterized in that it is determined based on the weighted sum of the multiple reference samples.
[Claim 11]
11. The method of claim 10, the image encoding method of weight applied to the plurality of reference samples each are characterized in that which is determined based on the distance to the first prediction samples.
[Claim 12]
12. The method of claim 11, wherein the plurality of reference samples, reference samples, and in a fixed position, the image encoding method comprising: a reference sample being determined dependent on the position of the first prediction samples.
[Claim 13]
The method of claim 12, wherein the reference to a fixed position sample, reference sample in which the comprises a reference sample adjacent to the upper left corner of the current block and the dependent determined by the position of the first prediction samples, the first prediction sample and the reference sample placed on the same horizontal line or the first prediction sample and comprises at least one of the reference sample placed on the same vertical line, the image encoding method.
[Claim 14]
12. The method of claim 11, wherein the image encoding method each of said plurality of reference sample is characterized in that included in the different reference lines.
[Claim 15]
The determining the intra prediction mode of the current block, and to induce the reference samples from the neighboring samples of the current block, based on the intra-prediction mode and the reference sample, to obtain a first predicted samples for the current block, and the image decoding apparatus including a first determining an offset for the prediction sample, intra-prediction to obtain a second prediction sample by applying the offset to the first prediction sample portion.