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 performing efficient inter-prediction with respect to the method as the coding / decoding a video signal, an encoding / decoding block.
[6]
The invention object of the present invention to provide a method and apparatus that can be in as coding / decoding video signals, determining a reference picture by a variable / adaptively weighted, and performs bi-directional prediction based on a weighted sum calculation of the plural prediction block It shall be.
[7]
An object of the present invention is to provide a method and apparatus that can be as in encoding / decoding a video signal, efficient encoding / decoding a weighted prediction parameter for determining the weights to be applied to both the reference picture.
[8]
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
[9]
A video signal decoding method and apparatus according to the present invention, based on the first prediction block and the second reference picture is generated based on a first reference picture obtaining the weighted prediction parameters for the current block, and based on the weighted prediction parameters determining a weight applied to the second prediction block to generate, the first prediction block and on the basis of the weighted sum of said second prediction block, it is possible to generate a predicted block of the current block.
[10]
Video signal coding method and apparatus according to the present invention, the second prediction comprising current on the basis of the weighted prediction parameters of the block, the first generation on the basis of the first reference picture prediction block and the generated based on a second reference picture determining a weight applied to the block, the first prediction block and based on a weighted sum of said second prediction block, it is possible to generate a predicted block of the current block.
[11]
In the video signal encoding / decoding method and apparatus according to the present invention, the weighted prediction parameters can be determined which of a plurality of candidate weighting prediction parameter specified by the index information into one.
[12]
In the video signal encoding / decoding method and apparatus according to the present invention, the index information may be binarized by a cutting-type unary binarization.
[13]
In the video signal encoding / decoding method and apparatus according to the present invention, the bit length of the index information, and wherein the temporal direction of the first reference picture and the second reference picture may be determined based on whether or not the same.
[14]
In the video signal encoding / decoding method and apparatus according to the invention, the distance and the current and the second reference picture between the current picture to the bit length of the index information, including the first the current block in the first reference picture at least one of a distance between pictures can be determined based on whether or not the same.
[15]
In the video signal encoding / decoding method and apparatus according to the present invention, the weighted prediction parameter, the current can be determined by any one of the candidates weighted prediction parameters included in the parameter set of the weighting prediction block.
[16]
In the video signal encoding / decoding method and apparatus according to the present invention, the weighted prediction parameter sets, wherein the distance between the current picture, including the current block and the first reference picture or reference the second picture and the current picture It may be determined based on at least one of a distance between.
[17]
In the video signal encoding / decoding method and apparatus according to the present invention, the weighted prediction parameter set, wherein the time direction of the first reference picture and the second reference picture may be determined based on whether or not equal.
[18]
In the video signal encoding / decoding method and apparatus according to the present invention, the weighted prediction parameters for the current block may be derived from a neighboring block surrounding the current block.
[19]
Time between in the video signal encoding / decoding method and apparatus according to the present invention, the weighted prediction parameters for the current block, the current picture and the second time sequence difference between the first reference picture and the current picture and the second reference picture sequence may be derived based on the difference.
[20]
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
[21]
According to the present invention, encoding / decoding can be efficiently performed by the inter prediction for the current block.
[22]
According to the present invention, it is possible to determine the weight on a per-picture bidirectional prediction reference variable / adaptive.
[23]
According to the present invention, the weighted prediction parameters to determine the amount weight to be applied to the reference picture can be efficiently encoding / decoding with.
[24]
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
[25]
Figure 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
[26]
Figure 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
[27]
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.
[28]
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.
[29]
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.
[30]
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.
[31]
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.
[32]
8 is a flow chart illustrating a process for obtaining a residual sample in one embodiment where the present invention is applied.
[33]
9 is a flow chart showing the inter-prediction method according to an embodiment to which the present invention is applied.
[34]
10 is a case where the merge mode applied to the current block, a diagram illustrating a process for deriving the motion information of the current block.
[35]
11 is a case where the AMVP mode applied to the current block, a diagram illustrating a process for deriving the motion information of the current block.
[36]
12 is a flow diagram of a two-way weighted prediction method according to an embodiment of the present invention.
[37]
13 is a view for explaining the principle of a two-way weighted prediction.
[38]
Figure 14 is a view showing the scanning order among neighboring blocks.
Mode for the Invention
[39]
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.
[40]
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.
[41]
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.
[42]
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.
[43]
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.
[44]
[45]
Figure 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
[46]
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
[47]
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.
[48]
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.
[49]
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.
[50]
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.
[51]
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.
[52]
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.
[53]
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.
[54]
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.
[55]
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.
[56]
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.
[57]
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.
[58]
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.
[59]
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.
[60]
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.
[61]
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.
[62]
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.
[63]
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.
[64]
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.
[65]
Reordering unit 160 may perform the reordering of the coefficient value for the quantized residual values.
[66]
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.
[67]
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).
[68]
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.
[69]
The entropy coding unit 165, the entropy encoding may be the coefficients of a coded unit of input in the rearrangement unit 160. The
[70]
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).
[71]
Filter unit 150 may include at least one of a deblocking filter, offset correction, ALF (Adaptive Loop Filter).
[72]
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.
[73]
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.
[74]
(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.
[75]
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).
[76]
[77]
Figure 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
[78]
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.
[79]
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.
[80]
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).
[81]
The entropy decoding unit 210, the can decrypt the information with regard to intra-prediction and inter-prediction performed in the encoder.
[82]
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.
[83]
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.
[84]
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.
[85]
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.
[86]
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.
[87]
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.
[88]
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.
[89]
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.
[90]
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.
[91]
The reconstructed block or picture may be provided to filter unit 240. Filter unit 240 may include the deblocking filter, offset correction, ALF.
[92]
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.
[93]
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.
[94]
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.
[95]
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.
[96]
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.
[97]
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).
[98]
[99]
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.
[100]
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.
[101]
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.
[102]
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.
[103]
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.
[104]
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.
[105]
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 are included in the coding block, 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.
[106]
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.
[107]
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.
[108]
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.
[109]
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.
[110]
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.
[111]
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.
[112]
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.
[113]
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.
[114]
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.
[115]
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.
[116]
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.
[117]
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.
[118]
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.
[119]
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.
[120]
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.
[121]
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.
[122]
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.
[123]
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.
[124]
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.
[125]
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.
[126]
Division result based on the quad-tree and tree-by battery, the coding unit may ttil a rectangle or square of any size.
[127]
[128]
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.
[129]
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.
[130]
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.
[131]
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.
[132]
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.
[133]
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.
[134]
[135]
8 is a flow chart illustrating a process for obtaining a residual sample in one embodiment where the present invention is applied.
[136]
First, it is possible to obtain the residual coefficients of the current block (S810). Decoder through a coefficient scanning method, it is possible to obtain the residual coefficients. For example, decoder, zig-zag by the scanning, vertical scanning or horizontal scanning, performs the scanning and counting, it is possible to obtain the residual coefficients of the resulting two-dimensional block format.
[137]
It may perform the inverse quantization to the residual coefficients of the current block (S820).
[138]
Optionally it is possible to perform the inverse transformation according to whether or not to skip the inverse transform to the de-quantized residual coefficients of the current block (S830). Specifically, the decoder may determine whether the horizontal or the skip (skip) the inverse transformation to at least one of the vertical direction of the current block. When it is determined to apply the inverse transform for at least one of the vertical or horizontal direction of the current block, by the inverse transform inverse quantized residual coefficients of the current block, it is possible to obtain a residual samples in the current block. Here, the inverse transformation may be performed using at least one of a DCT, DST or KLT.
[139]
If the inverse transformation is skipped for both horizontal and vertical directions of a current block, the inverse transform is not carried out at this time in the horizontal direction and vertical direction of the block. In this case, by scaling the de-quantized residual coefficients to the group set value, it is possible to obtain a residual samples in the current block.
[140]
Omitting the inverse transformation in the horizontal direction, the horizontal direction without performing an inverse transform and a vertical direction by means of performing the inverse transform. At this time, the horizontal direction may be scaled to be performed.
[141]
Omitting the inversion in the vertical direction, the vertical direction is to not perform the reverse conversion, the horizontal direction means to perform the inverse transformation. At this time, the vertical direction may be scaled to be performed.
[142]
In accordance with the split type of a current block, it may be determined whether or not whether to use the reverse skipping techniques for the current block. For example, when the current block is probably created by the division of a binary tree-based, may be restricted from using inversion techniques skipped for the current block. Accordingly, if the current block is probably created by the division of a binary tree-based, by inverse transformation of the current block, it is possible to obtain a residual samples in the current block. In addition, the encoding / decoding when the current block is probably generated by the division of a binary tree-based information (e.g., transform_skip_flag) indicating whether inversion is a skip can be omitted.
[143]
Alternatively, it is possible to limit the current block only in inversion techniques allow a skip binary tree when a base generated through the division, at least one of a horizontal direction or a vertical direction. Here, the direction in which the reverse skip techniques limit, or determined based on information decoded from the bitstream, the current block size, based on at least one of intra-prediction mode of the form or the current block of the current block may be determined adaptively have.
[144]
For example, the current block can be wide when the large non-square block than the height, allowing the inverse transform scheme skips only the vertical direction, and limits the reverse skipping techniques used for the horizontal direction. That is, if the current block 2NxN, the horizontal direction of the current block is the inverse transform is performed, is in the vertical direction can be selectively performed in the inverse transformation.
[145]
On the other hand, it may be present if the height is greater than the width of the non-square block blocks, and allows for reverse skipping technique only for the horizontal direction, and limit the use reverse skipping techniques for the vertical direction. That is, if the current block Nx2N, in the vertical direction of the current block is the inverse transform is performed, in a horizontal direction can be selectively carried out in the inverse transform.
[146]
If this example, as opposed to the current block of the one width of the largest non-square block than the height, if only reverse skip allows the techniques, the current block is a height of a large non-square block than the width in the horizontal direction, inversion only in the vertical direction It may be allowed to skip techniques.
[147]
Information indicating whether or not to skip an inversion of the information or the vertical direction on whether to skip the inverse transformation with respect to the horizontal direction can be signaled via the bitstream. In one example, the information indicating whether or not to skip a reverse conversion on the horizontal direction is a one-bit flag, 'hor_transform_skip_flag', information indicating whether or not to skip a reverse conversion on the vertical direction of the one-bit flag, 'ver_transform_skip_flag "there could be. Encoder, can be encoded in at least one of a, 'hor_transform_skip_flag' or 'ver_transform_skip_flag' according to the type of the current block. In addition, the decoder may determine whether use of the 'hor_transform_skip_flag' or 'ver_transform_skip_flag' at least, that the inverse transform in the horizontal direction or the vertical direction skipped.
[148]
In accordance with the split type of the current block, with respect to any direction, it may be set so that the inverse transform is omitted. For example, when the current block is generated by the division of a binary tree-based, may be omitted in the horizontal direction or the inverse transform in the vertical direction. That is, if the current block is generated by division of a binary tree-based, the horizontal or vertical direction with respect to the current block without encoding / decoding the current block information that indicates whether the inversion is skipped (e.g., transform_skip_flag, hor_transform_skip_flag, ver_transform_skip_flag) one may decide to skip the inverse transform for at least one.
[149]
[150]
9 is a flow chart showing the inter-prediction method according to an embodiment to which the present invention is applied.
[151]
Referring to Figure 9, it is possible to determine the motion information of the current block (S910). The motion information of the current block, may include at least one of inter-prediction direction, the reference picture index of motion vector or the current block, the current block of the current block.
[152]
The motion information of the current block may be obtained on the basis of at least one of motion information of neighboring blocks adjacent to the current block, or information that is signaled via the bitstream.
[153]
10 is a case where the merge mode applied to the current block, a diagram illustrating a process for deriving the motion information of the current block.
[154]
When the merge mode applied to the current block, it is possible to derive the spatial merge candidates from the spatially neighboring blocks of the current block (S1010). Spatially neighboring blocks, it is possible to sense at least one of a block adjacent to the current top of the blocks, or the left corner of the current block (for example, at least one of the upper left corner, upper right corner, or bottom left corner).
[155]
The motion information of the spatial merge candidates, can be set equal to the motion information of the spatial neighboring blocks.
[156]
It can derive the time remaining from the time the candidate neighboring blocks of the current block (S1020). Temporally neighboring blocks, may refer to the block with the K Colo suited picture. Colo K suited picture is the current picture has a different temporal order (Picture Order Count, POC) that contains the current block. Colo Kate picture may be determined by the index of crystal or a picture having an index defined groups within the reference picture list, and signaling from the bitstream. Temporally neighboring blocks, and can be determined in a block adjacent to the block or, Colo K lactide block including the coordinate in the Colo K lactide-picture in the current block in the same position suited Colo K blocks. For example, K may be determined in Colo suited block including the center coordinates of the blocks, or, at least one temporally adjacent block of the block adjacent the bottom of the left boundary of colo K lactide block.
[157]
Motion information on a time remaining candidates, may be determined based on the motion information of temporally neighboring blocks. For example, motion vector of the temporal merge candidates, may be determined based on the motion vector of the temporally neighboring blocks. In addition, the inter-prediction in the temporal direction, the remaining candidates can be set equal to the inter-prediction in the temporal direction neighboring blocks. However, a reference picture index for the time remaining candidates, may have a fixed value. For example, a reference picture index for the time remaining candidates may be set to '0'.
[158]
Then, it is possible to generate a merge candidate list including the spatial and temporal merge candidates remaining candidate (S1030). If, in the case the number of remaining candidates included in the candidate list the remaining less than the maximum number of remaining candidate, the combined remaining candidate a combination of two or more of the remaining candidates can be included in the merge candidate list.
[159]
If the remaining candidate list is generated on the basis of the remaining candidate index, it is possible to specify at least one of the remaining candidates included in the merge candidate list (S1040).
[160]
The motion information of the current block, may be set equal to the motion information on the remaining candidate specified by the merge candidate index (S1050). For example, by a merge candidate index, in the case where the spatial merge candidate is selected, the motion information of the current block, may be set equal to the motion information of the spatial neighboring blocks. Or, in the case by the remaining candidate index, time remaining candidate is selected, the motion information of the current block, may be set equal to the motion information of temporally neighboring blocks.
[161]
11 is a case where the AMVP mode applied to the current block, a diagram illustrating a process for deriving the motion information of the current block.
[162]
When the mode AMVP applied to a current block, from the bit stream it can be decoded at least one of the current inter-prediction direction, or a reference picture index for the block (S1110). That is, when the mode AMVP applied, at least one of the current inter-prediction direction, or a reference picture index for the block may be determined based on the encoded information in the bit stream.
[163]
Based on the motion vectors of spatially neighboring blocks of the current block, it is possible to determine the spatial motion vector candidates (S1120). Spatial motion vector candidates, may include at least one of the second spatial motion vector candidates derived from the first spatial motion vector candidates and the left neighboring block of the current block is derived from a top neighboring block of the current block. Here, the upper adjacent block and including at least one block adjacent the top or the upper right corner of the current block and the left neighboring block to the current block is to include at least one of a block adjacent to the left side or the lower left corner of the current block can. A block adjacent to the upper left corner of the current block, may be treated in the top of the neighboring block, or may be treated as the left neighboring block.
[164]
If the reference picture is present between the current block and spatially neighboring blocks a different spatial motion vector may be obtained by scaling the motion vectors of spatially neighboring blocks.
[165]
On the basis of a motion vector of a temporally adjacent block of the current block, it is possible to determine the temporal motion vector candidate (S1130). If the reference picture is present between the current block and temporally adjacent blocks are different, the temporal motion vector may be obtained by scaling the motion vector of the temporally neighboring blocks.
[166]
It may generate a list of candidate motion vectors including a motion vector candidate spatial and temporal motion vector candidates (S1140).
[167]
When the motion vector candidate list is generated, on the basis of at least one of a motion vector candidate list in which specific information, it is possible to specify at least one of the candidate motion vectors it included in the motion vector candidate list (S1150).
[168]
The motion vector candidate specified by the information, set to the current block in the motion vector prediction value and the combined motion vector difference value of the motion vector predicted value, it is possible to obtain a motion vector of a current block (S1160). At this time, the motion vector difference values, can be parsed by the bit stream.
[169]
When the current block in the motion information is obtained, based on the obtained motion information, it is possible to perform motion compensation of the current block (S920). Specifically, on the basis of the inter-prediction direction of a current block, the reference picture index and the motion vector, the motion compensation may be performed for the current block.
[170]
Inter prediction direction may be directed to the N direction. Here, N may be greater than or equal to a natural number, 1, 2 or 3; The inter-prediction direction is the N direction on the basis of the N number of reference pictures, or N number of reference blocks, may indicate that the current block of the inter-prediction is performed. For example, when the inter-prediction direction of a current block indicates a one-way, inter-prediction of the current block is, if the other hand is performed based on one reference picture, the inter-prediction of the current block indicates a two-way, the current block inter prediction may be performed by using two reference pictures or two reference blocks of the.
[171]
That are allowed for a plurality of way prediction block is checked it may be determined based on at least one of the size or type of the current block. For example, when the coding unit is in the case of a square shape, which, coding unit is non room type, while allowing the encoding / decoding using a plurality of directional prediction, there can be set to allow only the encoding / decoding using the one-way prediction. On the other hand, when the coding unit is abnormal room shape, on the other hand to allow coding / decoding using a plurality of bi-prediction, if the encoding unit is a square shape, and may be set to allow only the encoding / decoding using the one-way prediction. Alternatively, the prediction unit if the non room partitions of sizes, such as 4x8 or 8x4, may be set so that the coding / decoding is not allowed, using a plurality bi-prediction.
[172]
Reference picture index, it is possible to specify a reference picture used for inter-prediction of the current block. More specifically, the reference picture index, it is possible to specify any of the reference picture included in the reference picture list. For example, when the inter-prediction direction of the current block is bi-specific, and by the reference picture list of the reference pictures contained in the L0 reference (the reference pictures L0) picture index L0, the reference picture (reference picture included in the reference picture list L1 L1) can be specified by the reference picture index L1.
[173]
The one of the reference pictures may be included in more than one reference picture list. Accordingly, even if the reference picture index of reference picture belonging to a reference picture and a reference picture list L1 belonging to the reference picture list L0 are different, in time order (Picture Order Count, POC) of the two reference pictures it can be the same.
[174]
Motion vectors, may be used to specify the position of the reference block corresponding to the prediction block of the current block within the reference picture. Reference picture based on the reference block that is specified by the in-motion vectors, may be the inter picture prediction for the current block is performed. For example, a pixel or an integer, by interpolating the integer pixel generated non-integer pixel included in the reference blocks can be generated as the predicted samples for the current block. Each have a reference block specified by the different motion vector may belong to the same reference picture. In one embodiment, the reference picture list L0, and reference picture list when the reference picture is selected from the same L1, L0, and the motion vector the motion vector by the L1 specified reference block is to be part of the same reference picture.
[175]
When, indicating the inter-prediction direction is more than one direction of the current block, as described above, the motion compensation of the current block may be performed based on the two or more reference pictures, or more than one reference block.
[176]
For example, when the current block is encoded in the bidirectional prediction, the prediction block of the current block, may be obtained based on the two reference blocks obtained from two reference pictures. Further, the residual blocks representing the difference between the predicted block obtained based on an original image, two reference block when the current block is encoded in the bidirectional prediction can be encoded / decoded.
[177]
When using two or more reference pictures, and each of the reference picture by applying the same or different weights, it is possible to perform motion compensation of the current block. Hereinafter, embodiments to be described hereinafter, when the inter-prediction direction is directed to two or more, it will be described in detail how to perform weighted prediction on the current block. However, for convenience of explanation, the inter-prediction direction of the current block is assumed to be bidirectional. However, it will be, even if three or more inter-prediction direction is one of the current block, an example embodiment will be described below can be applied is applied. In addition, there will be referred to as two predictive image using the performing the motion compensation of the current block, bi-directional prediction method or bi-directional prediction encoding / decoding method.
[178]
When bi-directional prediction is applied for the current block, the reference picture to be used in bi-directional prediction of the current block is a temporal sequence (Picture Order Count, POC) is in-picture, the temporal sequence miraein picture or the current from the current picture past than the current picture the picture can be. For example, any one of two reference pictures are the past pictures are temporal order than the current picture, and the other may be, the time sequence miraein picture than the current picture. Alternatively, either of the two reference picture is the current picture, and the other may be a current picture than the temporal order in which the past picture or the temporal order miraein picture than the current picture. Alternatively, or both of the two reference pictures are the past time sequence than the current picture is a picture, it can be a time sequence miraein picture than the current picture. Alternatively, it may be all of two reference picture current picture.
[179]
2 from each of the reference picture list, there are two predicted block can be generated. For example, on the basis of the motion vector L0, a prediction block based on reference picture L0 is generated on the basis of the motion vector L1, there is a prediction block based on reference picture L1 can be generated. The predicted block generated by the prediction block and a motion vector generated by the motion vector L0 L1 may be generated based on the same reference picture.
[180]
Prediction block of the current block, may be obtained the average of the prediction block generated based on the amount of reference pictures as the basis. For example, equation (1), based on the average value of the plurality of prediction blocks, an example of obtaining the prediction block of the current block.
[181]
[Formula 1]

[182]
In Equation 1, P (x) is the final prediction sample or a complex means that the predicted prediction sample, and P of the current block N (x), the mean sample value of the predicted block LN generated based on the reference picture LN do. For example, P 0 (x), the mean prediction samples of the prediction block generated based on the reference pictures L0, and, P 1 mean the prediction samples of the prediction block generated based on the (x) is a reference picture L1 can. That is, according to the equation (1), the final prediction block of the current block, may be obtained based on a weighted sum of a plurality of prediction block generated based on a plurality of reference pictures. At this time, each of the prediction block, the weight for a fixed value defined based on the encoder / decoder can be given.
[183]
According to one embodiment of the invention, a final prediction block of the current block has been obtained based on a weighted sum of a plurality of prediction blocks, at this time, the weight given to each prediction block may be determined as a variable / adaptive. For example, a bi-directional prediction for the amount of a reference picture or a positive prediction, if blocks having different brightness, rather than by averaging the amount of prediction blocks to perform bidirectional prediction, both the prediction block of the current block by giving different weight to each it can be effective to perform. For the following, convenience of explanation, there will be a bi-directional prediction method when the weight is variable / adaptively determined imparted to each of the prediction blocks referred as "two-way weighted prediction.
[184]
That the current two-way weighted prediction is permitted in the block is checked may be determined based on at least one of the size or type of the current block. For example, it may be set so that the coding unit in the case of a square shape, in the case of, the non-coding unit type room, while allowing the encoding / decoding using a weighted prediction, the two-way, two-way weighted prediction is not permitted. On the other hand, when the coding unit type of non room, while allowing the encoding / decoding using the two-way weighted prediction, if the encoding unit is a square shape, and may be set to the two-way weighted prediction is not allowed. Alternatively, the prediction unit if the non room partitions of sizes, such as 4x8 or 8x4, may be set to the encoding / decoding using a weighted prediction bidirectional not allowed.
[185]
12 is a flow diagram of a two-way weighted prediction method according to an embodiment of the present invention.
[186]
To perform two-way weighted prediction, one can determine the weighted prediction parameters for the current block (S1210). Weighted prediction parameters, may be used to determine the weights to be applied to both the reference picture. For example, as shown in the example in shown in Figure 13, the reference picture prediction block generated based on L0 there is applied the weight of the 1-w, could have applied the weight of the w predicted block it generated based on a reference picture L1 have. Based on the weighted prediction parameters, to determine the weight to be applied for each prediction block (S1220), based on the determined weight value, by performing a weighted sum calculation of the plural predictive blocks, it may generate a final prediction block of the current block (S1230 ). For example, the final prediction block of the current block is to be generated based on equation (2).
[187]
[Formula 2]

[188]
In Equation 2, w represents the weighted prediction parameters.
[189]
As shown in equation (2), a prediction block P 0 are assigned a weight of 1-w, and the predicted block P 1 by applying There w weight of, a final prediction block of the current block P (x) can be obtained. As represented in equation (2) On the other hand, the prediction block P 0 given a weight of w to, and the predicted block P 1 it is also possible to assign a weight of 1-w on.
[190]
Weighted prediction parameters may be determined based on the distance (that is, POC difference) between the reference may be determined based on the brightness difference between the pictures, the current picture and the reference picture. Alternatively, it is also possible that, weighted prediction parameters based on the size or type of the current block is determined.
[191]
Weighted prediction parameters, block or determined (e. G., Coding tree unit, a coding unit, a prediction unit or the conversion unit basis), can be determined in a slice or picture basis.
[192]
At this time, the weighted prediction parameters may be determined based on the candidates weighted prediction parameter definer. For example, weighted prediction parameters, - 1/4, 1/4, 3/8, 1/2, 5/8, can be determined by any one of 3/4 or 5/4, such as previously defined values.
[193]
Alternatively, it is also possible to determine, weighted prediction parameters from the at least one candidate weighting predictive parameter includes a weighting prediction parameter set after determining a weighted prediction parameter set for the current block, it is determined. Weighted prediction parameter set, block or determined (e. G., Coding tree unit, a coding unit, a prediction unit or the conversion unit basis), can be determined in a slice or picture basis.
[194]
For example, if any one of the weighted prediction parameter set w0 and w1 is selected, it is possible to determine at least one of a weighting prediction parameter candidates contained in the selected weighted prediction parameter set by the weighted prediction parameters for the current block. For example, w0 = {-1/4, 1/4, 3/8, 1/2, 5/8, 3/4, 5/4} and w1 = {-3/8, -1/4, 1 / 4, it is assumed to be 3/8, 1/2, 5/8, 3/4}. When weighted prediction parameter set w0 is selected, the weighting parameter w prediction of the current block is a candidate weighted prediction parameters included in the w0, -1/4, 1/4, 3/8, 1/2, 5/8, 3/4 one, 5/4 can be determined by any one.
[195]
Weighted prediction parameter set in the current block is available it may be determined in accordance with the temporal sequence or the temporal direction of the reference pictures used for bidirectional prediction. Temporal order, may indicate the encoding / decoding order, the inter picture can represent the output order (for example, POC) of the picture. In addition, the temporal direction, the temporal order of the reference picture may indicate whether or not the past or future than the current picture.
[196]
For example, depending on whether or not the two reference pictures used for the two-way prediction it has the same temporal sequence, a weighting prediction parameter set in the current picture to be used can be determined. For example, depending on whether the reference pictures L0, and the reference picture L1, the same picture (i.e., the temporal order in which the same picture), whether or the reference pictures L0, and the reference picture L1 is different from the picture (that is, a time sequence different from the picture), the current block a weighting prediction parameter set that can be used can be differently determined.
[197]
Different weighted prediction parameter set, it means that the absolute value of the weighted prediction weighted prediction parameters included in the parameter set, the code (sign), at least one of a different number. For example, when the temporal direction of the reference pictures L0 and L1 the same reference picture, weighted prediction parameters set w0 = {-1/4, 1/4, 3/8, 1/2, 5/8, 3/4, 5/4} is used, and if the temporal direction of the reference pictures L0 and L1 reference picture different from the weighted prediction parameters w1 = {-3/8, -1/4, 1/4, 3/8, 1/2, 5 / 8, 3.4} may be used.
[198]
In one embodiment, each of the temporal direction, the two reference pictures used for the bi-directional prediction according to the same whether or not, a weighting prediction parameter set in the current picture to be used can be determined. For example, in case the second time when the direction of the reference picture is equal to 2, each time the direction of reference picture is different, a weighted prediction parameter set in the current block is available may be determined differently. Specifically, for example, the reference pictures L0, and whether the reference picture L1 are both whether the previous picture of the current picture, the reference pictures L0, and the reference picture L1 all different from the next picture and whether and reference picture temporally direction L0 and the reference picture L1 of the current picture depending on whether or not, the weighted prediction parameters for the current block can be configured differently.
[199]
The number of available candidate weighted prediction parameters or the number of available weighting prediction parameter set may be configured differently for each block, slice or picture. For example, on a slice-by-slice basis, the number of available candidate weighted prediction parameters or the number of available weighting prediction parameter set can be signaled. Accordingly, the number of available candidate weighted prediction parameters or the number of available weighting prediction parameter set for each slice may differ.
[200]
Weighted prediction parameters may be derived from a neighboring block adjacent to the current block. Here, the neighboring block is adjacent to a current block, it may include at least one of spatially neighboring blocks or temporally neighboring blocks of the current block.
[201]
For example, weighted prediction parameters for the current block, the current block is set as the weighted prediction parameters minimum or maximum value of the neighborhood of surrounding blocks adjacent to, or be set to a weighted average of the predictive parameter of the surrounding neighboring blocks.
[202]
For example, weighted prediction parameters for the current block, and one of the neighboring blocks adjacent to the current block can be derived from a neighboring block, which exists in a predetermined position. Here, the predetermined position may be determined in a variable or fixed. Specifically, the position of the neighboring block is the current block (e.g., a coding unit, a prediction unit or the conversion unit and the like), size, and locations of the current block coding tree unit, in the form of a current block (e.g., the partition type of the current block), or the current or the like on the basis of the partition index of the block can be determined in a variable. Alternatively, the position of the neighboring blocks in the group, the encoder / decoder-defined may be determined fixedly.
[203]
For example, weighted prediction parameters for the current block may be a two-way weighted prediction of neighboring blocks adjacent to the current block is derived from a neighboring block is applied. Specifically, from the weighted prediction parameters of time, the neighboring block is a two-way weighted prediction of the first navigation applied hayeoteul scanning the neighboring blocks adjacent to the current block in a predetermined order, it is possible to derive the weighted prediction parameters for the current block. Figure 14 is a view showing the scanning order among neighboring blocks. In Figure 14, but shown as the scan order seasonal left adjacent block, upper adjacent block, upper right neighbor block, lower left block and adjacent the upper left neighboring block, but the invention is not limited to the illustrated example. Group - when performing the scan in accordance with a defined scanning order, the weighted prediction parameters of the neighboring block is a two-way weighted prediction of the first occurrence of the applied weight may be used as a predictive parameter for the current block.
[204]
Or a group - the weighted prediction parameters at the time when performing the scan in accordance with a defined scanning order, the neighboring two-way weighted prediction weighting applied to the first occurrence of the block may be set to the current weighted prediction parameter prediction value of the block. In this case, by using a weighted prediction parameters and prediction value weighted prediction parameter difference value, a weighted prediction parameters for the current block can be obtained.
[205]
For example, weighted prediction parameters for the current block, or derived from the motion information and the merged spatially or temporally neighboring blocks of the current block may be derived from a spatially or temporally neighboring blocks used to derive the motion vector prediction value of the current block.
[206]
Information for determining the weighted prediction parameters, and may be signaled via the bitstream. For example, on the basis of any one of the index information or the weighted prediction parameter set for specifying any one of a weighted prediction information representing the value of the parameter candidates, weighted prediction parameters to at least one of a particular set of index information, the weighted prediction of the current block is a parameter can be determined.
[207]
Making a binary weighted prediction parameters a parameter is encoded, it is possible to map the smallest binary code word to a statistically higher frequency of the use weighted prediction parameters. For example, it is possible to perform a cutting-type unary binarization (Truncated Binarization Unary) for, weighted prediction parameters, as shown in the following Table 1. Table 1 is an example of the case where the cMax 6.
[208]
TABLE 1
index Weighted prediction parameters Binary code word
0 -1/4 111111
1 1/4 11110
2 3/8 110
3 1/2 0
4 5/8 10
5 3/4 1110
6 5/4 111110

[209]
Cutting type unary binarization shown in Table 1 is basically the same as the one unary binarization method, there are differences to perform the conversion in advance, and then receives a maximum value (cMax) of the input. Table 2 illustrates the cMax 13 of the cutting type unary binarization.
[210]
TABLE 2
Value Binarization
0 0
1 1 0
2 1 1 0
3 1 1 1 0
...
12 1 1 1 1 1 1 1 1 1 1 1 1 0
13 1 1 1 1 1 1 1 1 1 1 1 1 1

[211]
Depending on whether the temporal direction of the reference picture to be used in bi-directional prediction it is the same, may be weighted prediction use a different binary code words when the binarization parameters. For example, Table 3 is an illustration of a binary code word according to whether the temporal direction of the reference pictures L0 and L1 are the same reference picture.
[212]
TABLE 3
index Weighted prediction parameters Binary code word bidirectional prediction in different directions Binary code word during each bi-directional prediction in the same direction
0 -1/4 111111 111110
1 1/4 11110 1110
2 3/8 110 10
3 1/2 0 0
4 5/8 10 110
5 3/4 1110 11110
6 5/4 111110 111110

[213]
According to the time sequence differences between the current picture and the reference picture may be a weighted prediction parameters for the current block is determined. Here, the temporal sequence differences, the encoding / decoding order, the output order differences, or differences between pictures between pictures (for example, POC difference) may indicate a. In one embodiment, at least one of a current picture and a reference picture (hereinafter referred to as a first reference distance) POC difference between L0 and the current picture to the reference POC difference between the picture L1 (hereinafter referred to as the second reference distance) based on this, it is possible to determine the weighted prediction parameters for the current picture.
[214]
Specifically, based on the first reference distance and the ratio of the second reference distance may be the weighted prediction parameters for the current block is determined. And the first reference distance w, a second case 2, the reference distance is h, w / (w + h) can be used in the weighted prediction parameters for the current block. For example, in the case the first reference distance and the second reference distance are the same, the weighted prediction parameters for the current block can be determined as 1/2. In addition, the distance and the first reference 1, in the case where the second reference distance is three, weighted prediction parameters for the current block can be determined as 1/4.
[215]
Alternatively, the reference distance w is 1, a may also be used in the weighted prediction parameters for the current block having the most similar to the second reference value when the distance h is a, candidate weighted prediction w / (w + h) of the parameters.
[216]
Or, considering the first reference distance and the second reference distance may be a binary weighted prediction parameters for the current block. Table 4 shows the first reference distance and a binary code word based on the second reference distance.
[217]
TABLE 4
index Weighted prediction parameters When the first reference distance and the second reference distance equal to When the first reference distance and the second reference distance is different (the first reference distance = 2, the second reference distance = 1) When the first reference distance and the second reference distance is different (see the first reference distance = 1, the second distance = 2)
0 -1/4 111111 111110 111111
1 1/4 11110 11110 0
2 3/8 110 1110 110
3 1/2 0 10 10
4 5/8 10 0 1110
5 3/4 1110 110 11110
6 5/4 111110 111110 111110

[218]
In the example shown in Table 4, when the first reference distance and the same when the second reference distance is therefore more likely weighted prediction parameter is set to 1/2, the first reference distance and the second reference distance are the same, 1 / 2 may be allocated the smallest code word in.
[219]
When the first reference distance and the second reference distance is different, it is possible to map the smallest binary code word to a statistically high frequency of use is the weighted prediction parameters. For example, in the case the first reference distance is larger than a second reference distance is, therefore more likely to be a larger weight given to the reference picture L1, map the smallest binary code word to a weighted prediction parameters of a value greater than one-half can do. On the other hand, the first reference distance is less than the second reference distance is, therefore more likely to be a larger weight given to the reference pictures L0, to map the smallest binary code word to a weighted prediction parameters of a value less than 1/2 can.
[220]
As illustrated in Table 4. In contrast, in the case larger than the first reference distance is a second distance, see, map the smallest binary code word to a weighted prediction parameters of a value less than 1/2, the first reference distance, see the second distance If smaller, it is possible to map the smallest binary code word to a weighted prediction parameters of a value greater than 1/2.
[221]
[222]
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
[223]
The present invention can be applied to electronic devices capable of encoding / decoding an image.

Claims
[Claim 1]
Obtaining a weighted prediction parameters for the current block; Determining on the basis of the weighted prediction parameters, the first reference picture generated on the basis of the first prediction block and the weighting applied to the second prediction block generated based on a second reference picture; And the first prediction block and, the image decoding method based on a weighted sum of said second prediction blocks, comprising the step of generating a final prediction block of the current block.
[Claim 2]
The method of claim 1 wherein obtaining the weighted prediction parameters, comprising: obtaining the index information; And, the image decoding method comprising the step of identifying one of a plurality of candidate weighting prediction parameter by the index information.
[Claim 3]
The method of claim 3, wherein the index information, video decoding method, characterized in that the binarized by a cutting-type unary binarization.
[Claim 4]
The method of claim 1 wherein obtaining the weighted prediction parameters, determining a weighted prediction parameter set for the current block; , The image decoding method comprising the step of identifying any of the candidate weighted prediction parameters included in the determined weighted prediction parameter set.
[Claim 5]
The method of claim 4, wherein on the basis of at least one of a distance between the weighted prediction parameter sets, the first reference picture and the current block is the distance between the current picture or the second reference picture and the current picture, including method for decoding an image, characterized in that the crystal.
[Claim 6]
The method of claim 4, wherein the weighted prediction parameter set is, the image decoding method characterized in that said first crystal and a first reference picture based on the first time whether or not the direction of the two reference pictures are the same.
[Claim 7]
The method of claim 1, wherein the weighted prediction parameters for the current block, the image decoding method, characterized in that derived from neighboring blocks surrounding the current block.
[Claim 8]
The method of claim 1, wherein the weighted prediction parameters for the current block is being derived based on a time sequence difference between the current picture and the second time sequence difference between the first reference picture and the current picture and the second reference picture method for decoding an image, according to.
[Claim 9]
Determining on the basis of the weighted prediction parameters for the current block, the first reference picture generated on the basis of the first prediction block and the weighting applied to the second prediction block generated based on a second reference picture; And the first prediction block, and, a video encoding method based on a weighted sum of said second prediction blocks, comprising the step of generating a final prediction block of the current block.
[Claim 10]
The method of claim 9 wherein the weighted prediction but the step for encoding the index information identifying the parameters further include the index information, the image encoding method, characterized in that the binarized by a cutting-type unary binarization.
[Claim 11]
11. The method of claim 10, the image encoding method the bit length of the index information, the first reference picture and the second, characterized in that the temporal direction of the second reference picture is determined based on whether or not the same.
[Claim 12]
The method of claim 10, wherein the bit length of the index information, the first reference picture and the distance between the current picture including a current block and the second reference picture and at least one and the same of the distance between the current picture characterized in that is determined based on whether or not, the image encoding method.
[Claim 13]
10. The method of claim 9, characterized in that further comprising the step of determining the weighted prediction parameter set for the current block, and the weighted prediction parameters, determined by any one of the candidates weighted prediction parameters included in the determined weighted prediction parameter set , a video encoding method.
[Claim 14]
The method of claim 13, wherein on the basis of at least one of a distance between the weighted prediction parameter sets, the first reference picture and the current block is the distance between the current picture or the second reference picture and the current picture, including the image encoding method, characterized in that the crystal.
[Claim 15]
Decoding unit for obtaining the weighted prediction parameters for the current block; And the first prediction block and the second on the basis of the weighted prediction parameters, and determine the first-generated first reference pikcheoeul basis of the first prediction block and the weighting applied to the second prediction block generated by the second reference pikcheoeul base, on the basis of the weighted sum of the prediction block, the prediction video decoding apparatus, including a generating a final prediction block of the current block.