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 that can perform, conversion / inversion as effective in encoding / decoding a video signal.
[6]
An object of the present invention is to provide a method and apparatus as in encoding / decoding a video signal, can determine the type of transformation of the current block is adaptively from a plurality of types of conversion candidates.
[7]
An object of the present invention is to provide a method and apparatus as in encoding / decoding a video signal, can determine the type of conversion in the vertical and horizontal transformation separately.
[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 may obtain the transformation coefficients of the current block, and the inverse quantizing the transform coefficients, and determines the set of transforms for the current block, wherein one of a plurality of conversion-type candidate determining the current transformation block type, and based on the determined type of conversion, it is possible to reverse the inverse quantized transform coefficients.
[10]
Video signal coding method and apparatus according to the present invention may obtain the transformation coefficients of the current block, and the inverse quantizing the transform coefficients, and determines the set of transforms for the current block, wherein one of a plurality of conversion-type candidate determining the current transformation block type, and based on the determined type of conversion, it is possible to reverse the inverse quantized transform coefficients.
[11]
In the video signal encoding / decoding method and apparatus according to the present invention, the conversion of the current block is set, it can be determined by the index information indicating at least one of a plurality of sets of conversion.
[12]
In the video signal encoding / decoding method and apparatus according to the invention, at least one of the types or the number of each type of conversion candidate of the plurality of sets of conversion it may be different.
[13]
In the video signal encoding / decoding method and apparatus according to the invention, at least one of the types or number of types of conversion candidates to contain the converted set, it can be differently determined according to whether or not the conversion the skip is allowed.
[14]
In the video signal encoding / decoding method and apparatus according to the present invention, the inverse transform, a horizontal transform, and includes a vertical conversion, and converts the set and the set of transforms for the vertical translation for the horizontal conversion can be determined independently.
[15]
In the video signal encoding / decoding method and apparatus according to the invention, the set of transforms and transform set for the vertical translation for the horizontal transform may be determined in accordance with the intra-prediction mode of the current block.
[16]
In the video signal encoding / decoding method and apparatus according to the present invention, the conversion type of the current block, based on at least one of the current block size, the shape or number of samples can be determined adaptively.
[17]
The for the invention briefly summarized above features are merely exemplary of yangsangil detailed description of the invention which will be described later, and are not intended to limit the scope of the invention.
Effects of the Invention
[18]
According to the present invention, encoding / decoding can be performed effectively transform / inverse transform for the current block.
[19]
According to the present invention, it may determine a type of the current transformation block adaptively from a plurality of types of conversion candidates.
[20]
According to the present invention, it may determine the type of conversion in the vertical and horizontal transformation separately.
[21]
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
[22]
Figure 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
[23]
Figure 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
[24]
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.
[25]
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.
[26]
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.
[27]
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.
[28]
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.
[29]
8 is a flow chart illustrating a process for obtaining a residual sample in one embodiment where the present invention is applied.
[30]
9 is a diagram illustrating whether or not for the 33 intra-prediction mode, using the horizontal and vertical conversion, the same conversion set.
[31]
Mode for the Invention
[32]
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.
[33]
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.
[34]
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.
[35]
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.
[36]
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.
[37]
[38]
Figure 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
[39]
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
[40]
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.
[41]
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.
[42]
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.
[43]
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.
[44]
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.
[45]
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.
[46]
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.
[47]
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.
[48]
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.
[49]
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.
[50]
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.
[51]
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.
[52]
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.
[53]
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.
[54]
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.
[55]
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.
[56]
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.
[57]
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.
[58]
Reordering unit 160 may perform the reordering of the coefficient value for the quantized residual values.
[59]
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.
[60]
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).
[61]
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.
[62]
The entropy coding unit 165, the entropy encoding may be the coefficients of a coded unit of input in the rearrangement unit 160. The
[63]
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).
[64]
Filter unit 150 may include at least one of a deblocking filter, offset correction, ALF (Adaptive Loop Filter).
[65]
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.
[66]
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.
[67]
(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.
[68]
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).
[69]
[70]
Figure 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
[71]
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.
[72]
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.
[73]
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).
[74]
The entropy decoding unit 210, the can decrypt the information with regard to intra-prediction and inter-prediction performed in the encoder.
[75]
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.
[76]
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.
[77]
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.
[78]
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.
[79]
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.
[80]
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.
[81]
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.
[82]
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.
[83]
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.
[84]
The reconstructed block or picture may be provided to filter unit 240. Filter unit 240 may include the deblocking filter, offset correction, ALF.
[85]
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.
[86]
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.
[87]
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.
[88]
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.
[89]
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.
[90]
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).
[91]
[92]
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.
[93]
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.
[94]
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.
[95]
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.
[96]
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.
[97]
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.
[98]
The input video signal is decoded by a predetermined block unit, the basic unit is referred to as a coded block for decoding Thus the input video signal. Coding block may be a unit for performing the intra / inter-prediction, transformation, quantization. Further, the coding block unit prediction mode is determined (e.g., the intra-prediction mode or the inter-prediction mode), the prediction block included in the coded blocks, it is possible to share the determined prediction mode. Coded block may be a square or non-square blocks of arbitrary size of 8x8 to 64x64 belonging to the range, it can be 128x128, 256x256, or a square or non-square block having a size more.
[99]
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.
[100]
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.
[101]
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.
[102]
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.
[103]
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.
[104]
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.
[105]
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.
[106]
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.
[107]
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.
[108]
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.
[109]
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.
[110]
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.
[111]
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.
[112]
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.
[113]
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.
[114]
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.
[115]
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.
[116]
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.
[117]
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.
[118]
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.
[119]
Division result based on the quad-tree and tree-by battery, the coding unit may ttil a rectangle or square of any size.
[120]
[121]
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.
[122]
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.
[123]
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.
[124]
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.
[125]
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.
[126]
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.
[127]
[128]
8 is a flow chart illustrating a process for obtaining a residual sample in one embodiment where the present invention is applied.
[129]
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, a decoder, a diagonal scanning, zigzag scanning and the up-light scanning, using a vertical scan or a horizontal scan, performs the scanning and counting, it is possible to obtain the residual coefficients of the resulting two-dimensional block format.
[130]
It may perform the inverse quantization to the residual coefficients of the current block (S820).
[131]
It may determine whether to skip the inverse transformation to the inverse 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 (S840). Here, the inverse transformation may be performed using at least one of a DCT, DST or KLT.
[132]
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 (S850).
[133]
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.
[134]
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.
[135]
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.
[136]
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.
[137]
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.
[138]
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.
[139]
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.
[140]
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.
[141]
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.
[142]
[143]
When it is determined to apply the inverse transform to the current block, it is possible to determine the type of conversion, and using the determined conversion type, performing the inverse transformation. Conversion type of the current block (e.g., transformation block or a coded block) may be determined based on at least one of the current magnitude or the coding mode of the block. Here, the encoding mode may indicate whether or not the prediction block that is coded in intra mode or in inter-coding mode corresponding to the coding blocks, or the transform blocks.
[144]
For example, for a 4x4 block coded in an intra mode, DST (specifically, DST-VII) the inverse transformation is carried out using, use, DCT (specifically, DCT-II) for the blocks of the other the inverse transform may be performed.
[145]
DST-VII is a matrix A of the equation 4 can be defined as. The inverse transform of the DST-VII is A 4 T can be defined as.
[146]
[Formula 1]

[147]
DCT-II for the 8x8 block is a matrix T in equation (2) 8 can be defined as. The inverse transform of the DCT-II is T 8 T can be defined as.
[148]
[Formula 2]

[149]
Sequence, a slice or a block-by-block basis, the selection criteria of the transform types can also be configured differently. In one embodiment, the slice 0, the other hand to apply DST for the transform block of a 4x4 size, encoded in the intra mode, the slice 0, it is possible to apply DST for the converted 8x8 blocks of more than coded in intra mode.
[150]
As another example, based on at least one of the number of samples included in the intra-prediction mode or the current block of the current block, and it may determine the type of the current transformation block adaptively. At this time, the number of samples are selected based on the transformation type, may have a fixed value may be determined from the information that is signaled via the bitstream. The information may be signaled through a level such as block, slag es header or the picture parameter set.
[151]
For example, the current block is applied only if the DST encoded to include a sample of less than 16, and the current block is an intra mode, the control of the can be applied to DCT. More specifically, for the 4x4, 2x8, or 8x2 blocks of the size encoded by intra prediction, and apply DST, it can be applied to DCT blocks for the other.
[152]
Or, converting the type of the current block can be determined from the set of candidates for the converted set including conversion. In this case, a code block or a conversion block-by-block basis, it is possible to use a different set of transforms. Alternatively, it is also possible to share the same set of transformation a plurality of transformation block included in the predetermined block code. To determine the set of transforms, the index information for identifying a set of transforms to convert blocks coded blocks or units can be signaled. Or, it may determine the conversion of the current block is set adaptively depending on the current block size, the shape, the coding mode, the intra-prediction mode or the number of samples.
[153]
Converting the set may include a plurality of conversion candidate type, which may selectively be used depending on the type, size, or number of samples in the transform block (or block coding). At this time, at least one of the number or the type of conversion candidate type comprising a set of transforms may be different.
[154]
Table 1 is a table showing the set of transforms including a different type of conversion candidates.
[155]
TABLE 1
Transform set Index Transform candidates 0 Transform candidates 1
0 DST-VII DCT-II
1 DST-VII DST-I
2 DST-VII DCT-VIII

[156]
Table 1 exemplified that the number of the types of conversion candidates included in the converted set two. The present invention is not limited, it is also possible to have one set of transforms, including three or four or more conversion candidate type.
[157]
In addition, the number of types, at least conversion candidates to one conversion of containing the set may be different from the number of conversion candidate type comprising a different set of transforms. In the slice header or the sequence may be a maximum number of conversion candidate type signaling including a set of transforms.
[158]
Conversion type of the current block can be determined to at least one of the conversion type includes a conversion candidate set. At this time, on the basis of such a transform block or the code block size, coding mode, the number of intra-prediction mode or the sample can be determined a conversion type of the transform block. Here, the intra-prediction mode of the block transform can be, for intra-prediction mode of the prediction block or the code block corresponding to the transform block.
[159]
For example, for the transformation the set index 0 is determined by converting a set of the current block, if the current block is a block of a 4x4 size, encoded in the intra mode, the conversion type candidates 0, that is, using DST-VII, and the present block In this case does not satisfy the conditions, the conversion candidate type 1, that is, it is possible to use a DCT-II.
[160]
Alternatively, the time conversion set index 2 is applied to when the decision to convert the set of the current block, if the current block is a block of a 4x4 or 8x8 size coded in intra mode, the conversion type candidates 0, that is, DST-VII, the current If a block does not satisfy the above conditions, it is possible to use a type conversion candidate 1, that is, DCT-VIII.
[161]
Depending on the size of the coding block, and may differently set the conversion candidate type selection condition of the transform block. For example, when the size of the coding block is less than or equal to 32x32, with respect to an intra mode of a 4x4 size transform blocks, the transform type transformation block applying the candidate zero, and does not satisfy the conditions for the encoding by transform-type candidate 1 the can also be applied. On the other hand, the conversion type candidate 1 for the case where the size of the coding block is greater than 32x32, intra mode, 4x4 or 8x8 size block transform type transformation block applying the candidate zero, and does not satisfy the conditions for the encoding in It can be applied.
[162]
Conversion type candidates may include a conversion the skip (skip transform) for the transform is not performed. Depending on whether the conversion the skip is allowed, at least one of the set of transforms the number of candidate types of conversion type or transformation type candidates for containing the can be configured differently. For example, if the transform_skip_enabled_flag indicating whether to allow the Skip conversion within predetermined picture 1, as shown in Table 2, may be used to convert the set further comprises a transformation into a skip-type conversion candidate. On the other hand, if the transform_skip_enabled_flag is 0, as shown in Table 1, it may be used that does not contain the set of transforms to convert a skip type conversion candidate.
[163]
TABLE 2
Transform set Index Transform candidates 0 Transform candidates 1 Transform candidates 2
0 DST-VII DCT-II Transform skip
1 DST-VII DST-I Transform skip
2 DST-VII DCT-VIII Transform skip

[164]
Horizontal conversion and conversion of the vertical-type conversion of the current block may be the same, the horizontal transformation and type conversion of the vertical type may be different. For example, the conversion from one type of candidate set conversion, or to the both horizontal and vertical conversion type, it can be applied to different types of conversion candidates in the conversion horizontal and vertical types, respectively.
[165]
As another example, the set of transforms for converting the current block in the horizontal and vertical transform may be the same, converting a set of horizontal and vertical transform conversion may be different. When using a different set of transforms to convert the horizontal and vertical transform, converting the set index for identifying a set of transforms for converting the set index and vertical transform to identify the set of transforms for converting the horizontal may be signaled separately.
[166]
In one embodiment, the horizontal conversion, the conversion using the set corresponding to the index 0, and the vertical transform may be used to convert the set corresponding to the index 1. If the current block is a block of a 4x4 size are encoded in intra-prediction, the vertical transform and a horizontal transform may be used to convert the type 1 candidate included in each of the set of transforms. Accordingly, the horizontal transformation using DST-II, the vertical transform may be used for DST-I.
[167]
In accordance with the intra-prediction mode of the current block, it is possible to decide whether or not to use the same set of transforms to convert a horizontal and vertical conversion. For convenience of explanation, the conversion set for the horizontal conversion is converted to the title set, and a vertical direction conversion converts the horizontal Setra is referred to a vertical direction change Setra.
[168]
For example, it is possible to use the intra prediction mode is the case, the horizontal and vertical transformation converts the different sets of conversion similar to the intra-prediction mode or the vertical direction is similar to the intra-prediction mode of the current block in the horizontal direction. Here, the intra-prediction mode may be similar to the horizontal comprises at least one of a vertical direction or the intra-prediction mode, the mode value within the difference between the intra-prediction mode is previously defined value in a vertical direction. In addition, the intra-prediction mode is similar to the vertical direction may include at least one of the intra-prediction mode, the mode value within the difference between the intra-prediction mode in the horizontal direction or the horizontal direction previously defined value. On the other hand, the intra-prediction mode or the non-directional mode of the current block, when the directional mode, which does not satisfy the condition, the vertical transform and a horizontal transform may use the same set of transforms. Alternatively, it is also possible if the current intra-prediction mode, the non-directional mode of the block, the set of conversion in the vertical direction and a horizontal transform to the current block to be different.
[169]
9 is a diagram illustrating whether or not for the 33 intra-prediction mode, using the horizontal and vertical conversion, the same conversion set. In the example shown in Figure 9, an intra prediction mode of the current block is shown as using a case, the vertical transform and a horizontal transform a different set of transforms including the range 7-13 or 23-29. On the other hand, it was shown to be the intra-prediction mode of the current block is applied to a case where the directional mode that is not included in the above range, the same set of transforms to the vertical transform and a horizontal transform.
[170]
If a block having the same intra-prediction mode and within a current block exists in a predetermined block unit, the transform set of the current block may be set equal to the converted sets of blocks having the same intra-prediction mode and the current block. Here, the predetermined unit may be a block having a block may be a block coding or a coding tree block, a predetermined size.
[171]
For example, the intra prediction mode is the vertical direction (e.g., the mode code 26), and the horizontal direction converts the set of the blocks is an index 2, the vertical direction transform set corresponding to the coding block transform block of the first position onto the scan sequence index it is assumed that the zero. Converting a block with a coded block in the vertical direction intra-prediction mode if (that is, the transform block corresponding to the prediction block with a vertical intra prediction mode) is more present, not the newly scanned transform block has not converted the set index value signaling can. Alternatively, conversion of the newly set scan conversion block may be applied to convert a set of the transform blocks with the intra-prediction mode in a direction perpendicular to the previous. That is, the horizontal direction transform the set of newly scanned transform block is determined by the index 2, a vertical direction transform the set may be determined with index 0.
[172]
As another example, if a block having the intra-prediction mode is similar to the in the current block a predetermined unit block is present, may be set equal to the converted set of blocks with the intra-prediction mode is similar to the transformation set in the current block is the current block. Here, the intra-prediction mode is similar to the current block, it may refer to intra-prediction mode, the predetermined range within the intra-prediction mode as a reference. For example, based on intra-prediction mode is the horizontal or vertical direction, a horizontal intra prediction mode or the intra-prediction mode from within ± a in the vertical direction can be determined that mutually similar.
[173]
For example, the intra prediction mode is the vertical direction (e.g., the mode code 26), and the horizontal direction converts the set of the blocks is an index 2, the vertical direction transform set corresponding to the coding block transform block of the first position onto the scan sequence index it is assumed that the zero. The intra-prediction mode is similar to the vertical direction within the coded block (e.g., the mode code 27) for having the transform block, if applicable (i.e., the transform block corresponding to the prediction block with a vertical intra prediction mode) is present, a new scan conversion block, the transformation set index value may be signaled. Alternatively, conversion of the newly set scan conversion block may be applied to convert a set of the transform blocks with the intra-prediction mode is similar to the intra-prediction mode of the current block in the past. That is, the horizontal direction transform the set of newly scanned transform block is determined by the index 2, a vertical direction transform the set may be determined with index 0.
[174]
At least one of the current horizontal direction or the vertical direction converts the set transformation set of blocks may be determined based on the intra-prediction mode of the current block. For example, Table 3, illustrates an example in which in accordance with the intra-prediction mode of the current block, a fixed set of transforms index assignment.
[175]
TABLE 3
Login Mode 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
H 2 1 0 1 0 1 0 1 0 0 0 0 0 1 0 1 0 1
V 1 1 0 1 0 1 0 1 2 2 2 2 2 1 0 1 0 1
Login Mode 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
H 0 1 0 1 0 1 2 2 2 2 2 1 0 1 0 1 0
V 0 1 0 1 0 1 0 0 0 0 0 1 0 1 0 1 0

[176]
If the current block is coded in inter-prediction, the set of transforms a group definition can be used for the current block. For example, when the current block is coded in inter-prediction, the set of transforms for the index 0 can be used for the current block.
[177]
Alternatively, when the coded block is the inter-prediction encoding, select a set of transforms and transform-coded blocks in the block for the coded blocks, can be used to convert the type candidates included in the converted set of coded blocks. At this time, the conversion type of each conversion block, the transform block size, or determined by the type, the information may be signaled via the bitstream to identify each conversion type conversion blocks are selected.
[178]
That are determined by the type of conversion of at least one block from a plurality of types of conversion candidates, multiple transcoding can be defined as (Multiple Adaptive Transform, AMT). Encoding a multi-conversion (Multiple Adaptive Transform, AMT) may be applied for a given size or a particular type of coded blocks. At this time, information on the size or form of the coded block with multiple transcoding can be applied may be signaled via the bitstream. Here, information on the size of the coding block can represent at least one of a maximum size or the minimum size. Also, the information may be signaled from at least one of a block-level, the slice header or sequence header.
[179]
[180]
Sequences or based on a different size / shape of a slice or a block to may optionally be used to convert the heterogeneous.
[181]
For example, in the slice 0, and using the DST when the intra-prediction mode, yet the transform block size 4x4, the other cases may be selected from the DCT. In Slice 1 using DST when the size of the intra-prediction mode, yet the transform block is less than or equal to 8x8, and may be selected from the DCT otherwise.
[182]
Based on at least one of a number of samples in the intra-prediction mode and the transform block may be selected heterologous transformation. Specifically, for example, less than 16, yet within the transform block by using DST if the intra-prediction mode, perform the transformation, can be also used in the other DCT block.
[183]
Specifically, for example, or the intra mode, yet 2x8 transform blocks may be used in the DCT-II (Discrete Cosine Transform) in the case of an intra mode, yet 8x2 transform block, and use the DST (Discrete Sine Transform), the other block.
[184]
At this time it can be two kinds of signaling a syntax conversion block selection indicator indicating a number of samples within the block serving as a reference for selecting a heterologous transformation like the slice header or the picture parameter set.
[185]
Sequence, a slice or block by block, the condition for selecting the conversion conditions, and the type 1 candidate may be different for selecting a conversion candidate type 0. For example, a slice in 0, while selecting the conversion type Candidate 0 only in the transform block of a 4x4 size, encoded in the intra mode, the slice at 0, to select a transform type 0, for a transform block of 8x8 or less coded in intra mode have.
[186]
As another example, based on at least one of intra-prediction mode or block within the number of samples, and may transform type is selected adaptively. At this time, the number of samples within the block that is selected based on the transformation type, may have a fixed value may be determined from the information that is signaled via the bitstream. The information may be signaled through a level such as block, slag es header or the picture parameter set.
[187]
In one embodiment, it contained within a sample of less than 16 the current block, and apply DST only if the current block is coded in intra mode. In the other cases can be applied to DCT. Specifically, for a 4x4, 2x8 or 8x2 transform block size in the intra prediction encoding, and applying a DST, it is possible to apply the DCT blocks for the other.
[188]
[189]
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
[190]
The present invention can be applied to electronic devices capable of encoding / decoding an image.

Claims
[Claim 1]
Obtaining transformation coefficients of the current block; The step of inverse quantizing the transform coefficients; Determining a set of transformation of the current block, also the converting set comprises a plurality of conversion candidate type; Determining one of the plurality of conversion candidates to the conversion-type type of the current block; And, the image decoding method based on the determined conversion type, comprising the step of inverse transformation to the inverse quantized transform coefficients.
[Claim 2]
The method of claim 1, wherein the transformation set in the current block, is determined on the basis of the index information will be decoded by the bit stream, the index information, characterized in that points to at least one of the plurality of the set of transforms, image decoding method .
[Claim 3]
The method of claim 2 wherein at least one of the types or the number of each type of conversion candidate of the plurality of sets of conversion is an image decoding method, characterized in that different.
[Claim 4]
The method of claim 1 wherein at least one of the types or number of types of conversion candidates to contain the converted set, characterized in, that the image decoding that transform skip is accepted differently determined depending on whether or not.
[Claim 5]
The method of claim 1, wherein the inverse transform, including the horizontal and vertical transform conversion, and the image decoding method characterized in that the set of transforms and transform set for the vertical translation for the horizontal conversion is determined independently.
[Claim 6]
The method of claim 5, wherein the set of transforms and transform set for the vertical translation for the horizontal conversion, image decoding method, characterized in that determined in accordance with the intra-prediction mode of the current block.
[Claim 7]
The method of claim 1, wherein the conversion type of the current block, the image decoding method characterized in that the determination is adaptively based on at least one of the current block size, the shape or number of samples.
[Claim 8]
Obtaining transformation coefficients of the current block; The step of inverse quantizing the transform coefficients; Determining a set of transformation of the current block, also the converting set comprises a plurality of conversion candidate type; Determining one of the plurality of conversion candidates to the conversion-type type of the current block; And, a video encoding method based on the determined conversion type, comprising the step of inverse transformation to the inverse quantized transform coefficients.
[Claim 9]
9. The method of claim 8 wherein the conversion of the current block is set, characterized in that, which is determined by the index information indicating at least one of a plurality of sets of conversion, a video encoding method.
[Claim 10]
The method of claim 9, wherein at least one of the type or the number of each type of conversion candidate of the plurality of sets of transform image encoding method, characterized in that different.
[Claim 11]
10. The method of claim 8, wherein at least one of the types or number of types of conversion candidates to contain the converted set, characterized in that the skip is acceptable that the conversion differently determined depending on whether or not, the image encoding method.
[Claim 12]
The method of claim 8, wherein the inverse transform, including the horizontal and vertical transform conversion, and the image encoding method characterized in that the set of transforms and transform set for the vertical translation for the horizontal conversion is determined independently.
[Claim 13]
The method of claim 12, wherein the set of transforms and transform set for the vertical translation for the horizontal conversion, image encoding method, characterized in that determined in accordance with the intra-prediction mode of the current block.
[Claim 14]
9. The method of claim 8 wherein the conversion type of the current block, the image encoding method, characterized in that the determined adaptively based on at least one of the current block size, the shape or number of samples.
[Claim 15]
An entropy decoding unit for decoding the transform coefficients of the current block; An inverse quantization unit for inverse quantizing the transform coefficients; And wherein the determining the set of transforms for the current block, at which time, the converting set comprises also, determines any one of a plurality of conversion-type candidate as a conversion type of the current block, a plurality of conversion-type candidate, and the determined transformation type the image decoding apparatus, which includes an inverse transformation to the inverse transform to the inversely quantized transform coefficients on the basis of.