Method for encoding / decoding block information using a quad tree and apparatus using the method

Abstract

To provide an encoding / decoding method of an intra-picture prediction mode using two candidate intra-picture prediction modes and a device using the method.SOLUTION: A decoding method of an intra-picture prediction mode includes steps of: determining, on the basis of 1-bit information, whether an intra-picture prediction mode of a present prediction unit is the same as a first candidate intra-picture prediction mode or as a second candidate intra-picture prediction mode; and determining, of the first candidate intra-picture prediction mode and the second candidate intra-picture prediction mode, which candidate intra-picture prediction mode is the same as the intra-picture prediction mode of the present prediction unit on the basis of additional 1-bit information, if the intra-picture prediction mode of the present prediction unit is the same as at least either the first candidate intra-picture prediction mode or the second candidate intra-picture prediction mode, and decoding the intra-picture prediction mode of the present prediction unit.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a method for encoding / decoding block information using a quadtree and an apparatus using the method, and more particularly to a video encoding / decoding method. [Background technology]

[0002] Recently, as HD (High Definition) broadcasting services have expanded not only domestically but also globally, many users have become accustomed to high-resolution, high-quality images, and as a result, many organizations are spurring the development of next-generation video equipment.In addition to HDTV, there has been growing interest in UHD (Ultra High Definition), which has a resolution four times that of HDTV, and there is a demand for compression techniques for higher-resolution, high-quality images.

[0003] For video compression, techniques such as inter-prediction, which predicts pixel values contained in a current picture from previous and / or subsequent pictures, intra-prediction, which predicts pixel values contained in a current picture using pixel information within the current picture, and entropy coding, which assigns short codes to symbols that occur frequently and long codes to symbols that occur less frequently, can be used.

[0004] Some video compression technologies provide a constant network bandwidth under a limited hardware operating environment without considering a dynamic network environment. However, a new compression technology is required to compress video data applicable to a network environment where the bandwidth changes from time to time. For this purpose, a scalable video encoding / decoding method can be used. Summary of the Invention [Problem to be solved by the invention]

[0005] A first object of the present invention is to provide a method for decoding transform unit information using a quadtree to improve video coding efficiency.

[0006] A second object of the present invention is to provide a method for decoding transform unit information using quadtree and joint coding methods to improve video coding efficiency.

[0007] A third object of the present invention is to provide an apparatus for decoding transform unit information using a quadtree to improve video coding efficiency.

[0008] A fourth object of the present invention is to provide an apparatus for decoding transform unit information using quadtree and joint coding methods to improve video coding efficiency. [Means for solving the problem]

[0009] According to one aspect of the present invention, a transform unit information decoding method using a quadtree structure includes the steps of: decoding integrated code block flag information in a transform unit; and decoding a partition information flag based on size information of the transform unit and the integrated code block flag information. The step of decoding the partition information flag based on the size information of the transform unit and the integrated code block flag information includes the steps of: decoding the code block flag information of the transform unit without decoding the partition information flag information if no transform coefficients exist in the transform unit; and decoding the code block flag information of the transform unit if the transform unit is not to be further partitioned based on the partition information flag. The transform unit information decoding method using a quadtree structure further includes the step of decoding the code block flag information of the transform unit without decoding the integrated code flag and the partition information flag if the size of the transform unit is the same as that of a smallest transform unit that is not to be partitioned into additional transform units. The integrated code block flag may be applied only at a fixed transformation depth, or may be applied at multiple transformation unit depths, with the transformation depth being defined by a predetermined parameter.

[0010] According to another aspect of the present invention, a method for decoding transform unit information using a quadtree structure includes the steps of: decoding pattern information of a transform unit based on a transform unit information combined flag obtained by combining and encoding an integrated code block flag and a transform information flag; and decoding code block flag information and split information flag information of the transform unit corresponding to the pattern information based on the pattern information. The pattern information is a variable generated based on the number of cases in which a code block flag exists in a given transform unit and the number of cases in which a split information flag exists. The pattern information is binary-coded based on a table using variable length coding. The pattern information is encoded based on 4-bit information in which a luminance code block flag value is expressed as the most significant bit (MSB), a cb code block flag as the MSB-1, a cr code block flag as the MSB-2, and a split_flag as the least significant bit (LSB).

[0011] According to another aspect of the present invention, there is provided a video decoding apparatus including: an entropy decoding unit that decodes integrated code block flag information and size information of a transform unit, decodes a partition information flag based on the integrated code block flag information and the size information of the transform unit, and decodes transform coefficients of the transform unit; and an inverse transform unit that inversely transforms the transform coefficient information of the transform unit provided from the entropy decoding unit. If there are no transform coefficients in the transform unit, the entropy decoding unit decodes the code block flag information of the transform unit without decoding the partition information flag information, and if the transform unit is not to be further partitioned based on the partition information flag, decodes the code block flag information of the transform unit. If the size of the transform unit is the same as that of a smallest transform unit that will not be partitioned into further transform units, the entropy decoding unit decodes the code block flag information of the transform unit without decoding the integrated code flag and the partition information flag.

[0012] According to another aspect of the present invention, a video decoding apparatus includes an entropy decoder that decodes pattern information of a transform unit based on a transform unit information combination flag, which is obtained by combining and encoding an integrated code block flag and a transform information flag, and decodes code block flag information and split information flag information of the transform unit corresponding to the pattern information based on the pattern information; and an inverse transform unit that inversely transforms transform coefficient information of the transform unit provided from the entropy decoder. The pattern information is generated based on the number of cases in which a code block flag exists in a given transform unit and the number of cases in which a split information flag exists. The pattern information is binary-coded based on a table using variable length coding. The pattern information is encoded based on 4-bit information in which a luminance code block flag value is represented by the most significant bit (MSB), a cb code block flag by the MSB-1, a cr code block flag by the MSB-2, and a split_flag by the least significant bit (LSB). [Effects of the Invention]

[0013] As described above, according to the method for encoding / decoding block information using a quad tree and the apparatus using the method, it is possible to represent transform coefficient information and partition information for a current transform unit using integration code flag information and partition information flag information. Therefore, it is possible to encode / decode transform coefficient information and partition information for a transform unit using fewer bits, thereby improving encoding / decoding efficiency. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a block diagram showing a video encoding device according to an embodiment of the present invention; [Figure 2] FIG. 10 is a block diagram illustrating a video decoder according to another embodiment of the present invention. [Figure 3]10 is a flowchart illustrating a method for transmitting transform unit information using a quadtree structure according to another embodiment of the present invention. [Figure 4] 10 is a conceptual diagram illustrating a method for applying an integrated code block flag and a division information flag according to another embodiment of the present invention. [Figure 5] 10 is a conceptual diagram illustrating a method for applying an integrated code block flag and a division information flag according to another embodiment of the present invention. [Figure 6] 10 is a conceptual diagram illustrating a method for applying an integrated code block flag and a division information flag according to another embodiment of the present invention. [Figure 7] 10 is a conceptual diagram illustrating how an integrated code block flag and a partition information flag are applied differently depending on depth information of a transform unit according to another embodiment of the present invention. [Figure 8] 10 is a conceptual diagram illustrating a process of decoding transform unit information in a quadtree structure according to another embodiment of the present invention. [Figure 9] 10 is a flowchart illustrating a method for encoding transform coefficient information and partition information of a transform unit when a transform unit information combination flag is used. [Figure 10] 10 is a conceptual diagram illustrating a method for combining and encoding an integration code flag and a division information flag in accordance with another embodiment of the present invention, and integrating transform unit information of transform units existing at the same depth. [Figure 11] 10 is a flowchart for decoding block information of a quadtree structure according to another embodiment of the present invention. [Figure 12] 10 is a flowchart illustrating a method for decoding transform unit information combination flag information according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention can be modified in various ways and can have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this does not limit the present invention to the specific embodiments, and it should be understood that the present invention includes all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention. Similar reference numerals are used to refer to similar components throughout the drawings.

[0016] Terms such as "first," "second," etc. may be used to describe various elements, but the elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element can be called a "second element," and similarly, a second element can be called a "first element," without departing from the scope of the present invention. The term "and / or" includes a combination of multiple related items or any of multiple related items.

[0017] When a component is said to be "coupled" or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but that there may be other components in between. Conversely, when a component is said to be "directly coupled" or "directly connected" to another component, it should be understood that there are no other components in between.

[0018] The terms used in this application are merely used to describe specific embodiments and do not limit the present invention. The singular expressions include the plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In the following, the same reference numerals are used to designate the same components in the drawings, and redundant description of the same components will be omitted.

[0020] FIG. 1 is a block diagram showing a video encoding device according to an embodiment of the present invention.

[0021] Referring to FIG. 1, the video encoding device 100 may include a picture division unit 105, a prediction unit 110, a transform unit 115, a quantization unit 120, a realignment unit 125, an entropy encoding unit 130, an inverse quantization unit 135, an inverse transform unit 140, a filter unit 145, and a memory 150.

[0022] 1 are shown independently to indicate different characteristic functions of the video encoding device, and do not mean that each component is a separate hardware or software component. That is, each component is listed as a separate component for the sake of convenience, and at least two of the components may be combined to form a single component, or a single component may be separated from multiple components to perform a function. Such integrated and separated embodiments of each component are also within the scope of the present invention as long as they do not deviate from the essence of the present invention.

[0023] In addition, some components are not essential components for performing essential functions of the present invention, but are optional components merely for improving performance. The present invention may be embodied by including only components essential for embodying the essence of the present invention, excluding components merely used for improving performance, and a structure including only essential components, excluding optional components merely used for improving performance, is also included in the scope of the present invention.

[0024] The picture division unit 105 can divide an input picture into at least one processing unit. At this time, the processing unit may be a prediction unit (PU), a transform unit (TU), or a coding unit (CU). The picture division unit 105 can divide one picture into a plurality of combinations of coding units, prediction units, and transform units, and select one combination of coding units, prediction units, and transform units based on a predetermined criterion (e.g., a cost function) to code the picture.

[0025] For example, one picture may be divided into multiple coding units. A recursive tree structure such as a quad tree structure may be used to divide coding units in a picture. A coding unit that is divided into other coding units with one image or a maximum-sized coding unit as the root may be divided into child nodes equal to the number of divided coding units. A coding unit that is not further divided due to a certain restriction becomes a leaf node. That is, assuming that only square division is possible for one coding unit, one coding unit may be divided into a maximum of four other coding units.

[0026] Hereinafter, in the embodiments of the present invention, the coding unit can be used to mean not only a unit for encoding but also a unit for decoding.

[0027] The prediction units may be divided into at least one square or rectangular shape of the same size within one coding unit, or the shape of one prediction unit may be different from the shape of a different prediction unit among the prediction units divided within one coding unit.

[0028] If a prediction unit for performing intra prediction based on a coding unit is not the smallest coding unit at the time of generation, intra prediction can be performed without dividing into a plurality of prediction units (N×N).

[0029] The prediction unit 110 may include an inter prediction unit that performs inter prediction and an intra prediction unit that performs intra prediction. It may determine whether to use inter prediction or intra prediction for a prediction unit, and determine specific information (e.g., intra prediction mode, motion vector, reference picture, etc.) according to each prediction method. Here, the processing unit in which prediction is performed and the processing unit in which the prediction method and specific content are determined may be different. For example, the prediction method and prediction mode may be determined for each prediction unit, and the prediction may be performed for each transform unit. Residual values (residual blocks) between the generated prediction block and the original block may be input to the transform unit 115. Information about the prediction mode and motion vectors used for prediction, along with the residual values, may be coded by the entropy coding unit 130 and transmitted to the decoder. When a specific coding mode is used, it is also possible to directly code the original block and transmit it to the decoder without generating a prediction block via the prediction unit 110.

[0030] The inter prediction unit may predict a prediction unit based on information of at least one picture between a previous picture and a subsequent picture of a current picture. The inter prediction unit may include a reference picture interpolation unit, a motion prediction unit, and a motion compensation unit.

[0031] The reference picture interpolator receives reference picture information from the memory 155 and generates sub-integer pixel information from the reference picture. In the case of luminance pixels, a DCT-based 8-tab interpolation filter with different filter coefficients can be used to generate sub-integer pixel information in 1 / 4 pixel units. In the case of chrominance signals, a DCT-based 4-tab interpolation filter with different filter coefficients can be used to generate sub-integer pixel information in 1 / 8 pixel units.

[0032] The motion prediction unit may perform motion prediction based on the reference picture interpolated by the reference picture interpolation unit. Various methods may be used to calculate a motion vector, such as a full search-based block matching algorithm (FBMA), a three-step search algorithm (TSS), or a new three-step search algorithm (NTS). The motion vector may have a motion vector value in half or quarter pixel units based on the interpolated pixels. The motion prediction unit may predict the current prediction unit using different motion prediction methods. Various methods may be used as the motion prediction method, such as a skip method, a merge method, or an advanced motion vector prediction method (AMVP).

[0033] The intra prediction unit may generate a prediction unit based on reference pixel information surrounding a current block, which is pixel information within a current picture. Since neighboring blocks of the current prediction unit are blocks on which inter prediction has been performed, if the reference pixels are pixels on which inter prediction has been performed, the reference pixels included in the blocks on which inter prediction has been performed may be replaced with reference pixel information of neighboring blocks on which intra prediction has been performed. In other words, if reference pixels are unavailable, the unavailable reference pixel information may be replaced with at least one reference pixel from available reference pixels.

[0034] In the intra prediction, the prediction mode may include a directional prediction mode that uses reference pixel information according to the prediction direction and a non-directional mode that does not use directional information when performing prediction. A mode for predicting luminance information and a mode for predicting chrominance information are different, and intra prediction mode information that predicts luminance information or predicted luminance signal information may be used to predict chrominance information.

[0035] When intra prediction is performed, if the size of the prediction unit and the size of the transform unit are the same, intra prediction for the prediction unit is performed based on the pixel located to the left of the prediction unit, the pixel located in the upper left corner, and the pixel located in the upper corner. However, when the size of the prediction unit and the size of the transform unit are different, intra prediction can be performed using reference pixels based on the transform unit. In addition, intra prediction using NxN division can be used only for the minimum coding unit.

[0036] The intra prediction method may generate a predicted block after applying an adaptive intra smoothing (AIS) filter to reference pixels according to a prediction mode. The type of AIS filter applied to the reference pixels may vary. To perform the intra prediction method, the intra prediction mode of a current prediction unit may be predicted from the intra prediction mode of a prediction unit existing in the vicinity of the current prediction unit. When predicting the prediction mode of the current prediction unit using mode information predicted from the surrounding prediction units, if the intra prediction modes of the current prediction unit and the surrounding prediction units are the same, information indicating that the prediction modes of the current prediction unit and the surrounding prediction units are the same may be transmitted using predetermined flag information. If the prediction modes of the current prediction unit and the surrounding prediction units are different, entropy coding may be performed to encode the prediction mode information of the current block.

[0037] In addition, a residual block including residual value information, which is a difference value between a prediction unit predicted based on a prediction unit generated by the prediction unit 110 and an original block of the prediction unit, may be generated. The generated residual block may be input to the transform unit 115. The transform unit 115 may transform the residual block including residual value information of the original block and the prediction unit generated by the prediction unit 110 using a transform method such as a Discrete Cosine Transform (DCT) or a Discrete Sine Transform (DST). Whether to apply the DCT or the DST to transform the residual block may be determined based on intra-frame prediction mode information of the prediction unit used to generate the residual block.

[0038] The quantization unit 120 quantizes the values converted into the frequency domain by the transformation unit 115. The quantization coefficients may vary depending on the block or the importance of the image. The values calculated by the quantization unit 120 may be provided to the inverse quantization unit 135 and the reordering unit 125.

[0039] The realignment unit 125 may perform realignment of coefficient values on the quantized residual values.

[0040] The reordering unit 125 may convert two-dimensional block configuration coefficients into one-dimensional vector forms through a coefficient scanning method. For example, the reordering unit 125 may convert two-dimensional block configuration coefficients into one-dimensional vector forms by scanning from DC coefficients to high-frequency coefficients using a zigzag scan method. Depending on the size of the transform unit and the intra-frame prediction mode, instead of the zigzag scan method, a vertical scan method in which two-dimensional block configuration coefficients are scanned in a column direction or a horizontal scan method in which two-dimensional block configuration coefficients are scanned in a row direction may be used. That is, depending on the size of the transform unit and the intra-frame prediction mode, it may be determined which scan method is used, zigzag scan, vertical scan, or horizontal scan.

[0041] The entropy coding unit 130 may perform entropy coding based on the value calculated by the reordering unit 125. The entropy coding may use various coding methods such as Exponential Golomb, Context-Adaptive Variable Length Coding (CAVLC), and Context-Adaptive Binary Arithmetic Coding (CABAC).

[0042] The entropy coding unit 130 can encode various information from the realignment unit 125 and the prediction unit 110, such as residual value coefficient information and block type information of the coding unit, prediction mode information, division unit information, prediction unit information and transmission unit information, motion vector information, reference frame information, block interpolation information, and filtering information.

[0043] The entropy coding unit 130 can entropy code the coefficient values of the coding unit input from the reordering unit 125 .

[0044] The entropy encoder 130 may store a table for performing entropy encoding, such as a variable length coding table, and may perform entropy encoding using the stored variable length coding table. When performing entropy encoding, the allocation of codewords to codenumbers of corresponding information may be changed using a method using a counter or a direct swapping method for some codewords included in the table. For example, in the case of some top codenumbers to which codewords with fewer bits are assigned in the codenumber-codeword mapping table, the mapping order of the codeword-codenumber mapping table may be adaptively changed so that a codeword with a shorter length may be assigned to the codenumber with the highest total occurrence frequency using a counter. When the number of counts in the counter reaches a predetermined threshold, the number of counts recorded in the counter may be divided in half and counting may be performed again.

[0045] For code numbers in a table that does not perform counting, if information corresponding to a code number occurs using a direct swapping method, the number of bits allocated to the corresponding code number can be reduced by converting the position with the code number immediately above, thereby performing entropy coding.

[0046] The entropy coding unit 130 may encode the merged code block flag at the current transform depth and encode the partition information flag based on the merged code block flag information. Also, the entropy coding unit 130 may combine and encode the partition information flag based on the merged code block flag information. Additional encoding methods will be described in the following embodiments of the present invention.

[0047] The inverse quantization unit 135 and the inverse transform unit 140 inversely quantize the values quantized by the quantization unit 120 and inversely transform the values transformed by the transform unit 115. Residual values generated by the inverse quantization unit 135 and the inverse transform unit 140 can be added to prediction units predicted through a motion estimation unit, a motion compensation unit, and an intra prediction unit included in the prediction unit 110 to generate reconstructed blocks.

[0048] The filter unit 145 may include at least one of a deblocking filter, an offset correction unit, and an adaptive loop filter (ALF).

[0049] The deblocking filter 145 can remove block distortion caused by boundaries between blocks in a reconstructed picture. To determine whether to perform deblocking, it can determine whether to apply a deblocking filter to a current block based on pixels included in several columns or rows included in the block. When applying a deblocking filter to a block, a strong filter or a weak filter can be applied depending on the required deblocking filtering strength. In addition, when performing vertical filtering and horizontal filtering in applying a deblocking filter, horizontal filtering and vertical filtering can be processed in parallel.

[0050] The offset correction unit may correct the offset between the deblocked image and the original image on a pixel-by-pixel basis. To perform offset correction for a specific picture, the offset correction unit may divide pixels included in the image into a certain number of regions, determine the regions to perform offsetting, and apply the offset to the corresponding regions, or may apply the offset by considering edge information of each pixel.

[0051] An adaptive loop filter (ALF) can perform filtering based on a comparison between a filtered restored image and the original image. After dividing pixels included in an image into predetermined groups, a filter to be applied to each group is determined, and differential filtering can be performed for each group. Information related to whether to apply an ALF can be transmitted for each coding unit (CU) of the luminance signal, and the magnitude and coefficients of the ALF applied to each block can vary. The ALF can have various forms, and the number of coefficients included can also vary depending on the filter. Such ALF filtering-related information (filter coefficient information, ALF On / Off information, filter type information) can be transmitted in a predetermined parameter set in the bitstream.

[0052] The memory 150 can store the reconstructed blocks or pictures calculated through the filter unit 145, and the stored reconstructed blocks or pictures can be provided to the prediction unit 110 when performing inter-frame prediction.

[0053] FIG. 2 is a block diagram illustrating a video decoder according to another embodiment of the present invention.

[0054] Referring to FIG. 2, the video decoder 200 may include an entropy decoding unit 2110 , a reordering unit 215 , an inverse quantization unit 220 , an inverse transform unit 225 , a prediction unit 230 , a filter unit 235 , and a memory 240 .

[0055] When a video bitstream is input from a video encoder, the input bitstream can be decoded in the reverse order of the video encoder.

[0056] The entropy decoding unit 210 may perform entropy decoding in the reverse order of the entropy encoding performed by the entropy encoding unit of the video encoder. For example, the VLC table used to perform entropy encoding in the video encoder may be implemented as the same variable length coding table in the entropy decoding unit to perform entropy decoding. Information for generating a prediction block from the information decoded by the entropy decoding unit 210 is provided to the prediction unit 230, and residual values obtained by entropy decoding in the entropy decoding unit may be input to the reordering unit 215.

[0057] Like the entropy coding unit, the entropy decoding unit 210 can change the codeword allocation table using a counter or direct swapping method, and can perform entropy decoding based on the changed codeword allocation table.

[0058] The entropy decoder may decode information related to intra prediction and inter prediction performed by the video encoder. As described above, if there are certain constraints on the execution of intra prediction and inter prediction in the video encoder, entropy decoding based on such constraints may be performed to receive information related to intra prediction and inter prediction for the current block. The entropy decoder may perform the decoding operations described in Figures 3 to 8 of the following exemplary embodiments of the present invention.

[0059] The entropy decoding unit 210 can decode integrated code block flag information for each transform unit, and decode partition information flags based on the size information of the transform unit and the integrated code block flag information. Also, the entropy decoding unit can decode pattern information for the transform unit based on a transform unit information combined flag, which is a combination of the integrated code block flag and the transform information flag, and can decode code block flag information and partition information flag information for the transform unit corresponding to the pattern information based on the pattern information. The entropy decoding process will be described in detail in the following embodiments of the present invention.

[0060] The reordering unit 215 may perform reordering of the bitstream entropy decoded by the entropy decoding unit 210 based on the reordering method used by the encoding unit. Coefficients expressed in a one-dimensional vector format may be restored to coefficients in a two-dimensional block format and reordered. The reordering unit may receive information related to coefficient scanning performed by the encoding unit and perform reordering by scanning in reverse based on the scanning order performed by the corresponding encoding unit.

[0061] The inverse quantization unit 220 may perform inverse quantization based on the quantization parameter provided by the encoder and the coefficient values of the reordered blocks.

[0062] The inverse transform unit 225 may perform an inverse DCT and an inverse DST on the DCT and DST performed by the transform unit on the quantization result performed by the video encoder. The inverse transform may be performed based on a transmission unit determined by the video encoder. In the transform unit of the video encoder, the DCT and DST may be selectively performed based on a plurality of pieces of information such as a prediction method, a size of the current block, and a prediction direction, and the inverse transform unit 225 of the video decoder may perform an inverse transform based on the transform information performed by the transform unit of the video encoder.

[0063] When a transform is performed, the transform can be performed on the basis of a coding unit that is not a transform unit.

[0064] The prediction unit 230 can generate a prediction block based on prediction block generation related information provided by the entropy decoding unit 210 and previously decoded block or picture information provided by the memory 240 .

[0065] As described above, similar to the operation of a video encoder, when intra prediction is performed, if the size of the prediction unit and the size of the transform unit are the same, intra prediction for the prediction unit is performed based on the pixel located to the left of the prediction unit, the pixel located in the upper left corner, and the pixel located in the upper corner. However, when intra prediction is performed, if the size of the prediction unit and the size of the transform unit are different, intra prediction can be performed using reference pixels based on the transform unit. In addition, intra prediction using NxN division can be used only for the smallest coding unit.

[0066] The prediction unit 230 may include a prediction unit determination unit, an inter prediction unit, and an intra prediction unit. The prediction unit determination unit may classify a prediction unit by a current coding unit based on various input information such as prediction unit information input from the entropy decoding unit, prediction mode information of the intra prediction method, and motion prediction-related information of the inter prediction method, and may determine whether the prediction unit performs inter prediction or intra prediction. The inter prediction unit may perform inter prediction on the current prediction unit based on information included in at least one of a picture previous to or a picture subsequent to the current picture including the current prediction unit, using information necessary for inter prediction of the current prediction unit provided by the video encoder.

[0067] In order to perform inter-frame prediction, it is possible to determine, based on the coding unit, whether the motion prediction method of the prediction unit included in the corresponding coding unit is skip mode, merge mode, or AMVP mode.

[0068] The intra prediction unit may generate a prediction block based on pixel information within a current picture. If the prediction unit is a prediction unit for which intra prediction has been performed, the intra prediction may be performed based on intra prediction mode information of the prediction unit provided by the video encoder. The intra prediction unit may include an AIS filter, a reference pixel interpolator, and a DC filter. The AIS filter performs filtering on reference pixels of the current block and may determine whether to apply a filter depending on the prediction mode of the current prediction unit and apply the filter. AIS filtering may be performed on reference pixels of the current block using the prediction mode of the prediction unit and AIS filter information provided by the video encoder. If the prediction mode of the current block is a mode that does not perform AIS filtering, the AIS filter is not applied.

[0069] The reference pixel interpolator may generate reference pixels in units of pixels less than an integer value by interpolating reference pixels when the prediction mode of the prediction unit is a prediction unit that performs intra-frame prediction based on pixel values obtained by interpolating reference pixels. When the prediction mode of the current prediction unit is a prediction mode that generates a prediction block without interpolating reference pixels, the reference pixels are not interpolated. When the prediction mode of the current block is a DC mode, the DC filter may generate a prediction block through filtering.

[0070] The reconstructed block or picture may be provided to a filter unit 235. The filter unit 235 may include a deblocking filter, an offset correction unit, and an ALF.

[0071] The video encoder may provide information on whether a deblocking filter has been applied to a corresponding block or picture, and, if a deblocking filter has been applied, information on whether a strong or weak filter has been applied. The deblocking filter of the video decoder may receive deblocking filter-related information provided by the video encoder and perform deblocking filtering on the corresponding block. As with the video encoder, vertical deblocking filtering and horizontal deblocking filtering may be performed first, and at least one of vertical deblocking filtering and horizontal deblocking filtering may be performed in the overlapping portion. Vertical deblocking filtering or horizontal deblocking filtering, which has not been performed previously, may be performed in the overlapping portion of the vertical deblocking filtering and horizontal deblocking filtering. Parallel processing of deblocking filtering is possible through this deblocking filtering process.

[0072] The offset correction unit may perform offset correction on the restored image based on the type of offset correction applied to the image during encoding and offset value information.

[0073] ALF can perform filtering based on a value obtained by comparing the restored image after filtering with the original image. ALF can be applied to a coding unit based on ALF applicability information, ALF coefficient information, etc. provided from the encoder. Such ALF information can be provided by being included in a specific parameter set.

[0074] The memory 240 can store reconstructed pictures or blocks for use as reference pictures or blocks, and can provide the reconstructed pictures to an output.

[0075] As described above, in the following embodiments of the present invention, for convenience of explanation, a coding unit is used as a coding unit, but it can also be used as a unit for performing not only encoding but also decoding. Hereinafter, the intra prediction mode encoding / decoding method using two candidate intra prediction modes described in Figures 3 to 12 according to embodiments of the present invention can be implemented in a manner suitable for the functions of each module described above in Figures 1 and 2, and such encoders and decoders are included in the scope of the present invention.

[0076] The binary codes used in the following embodiments of the present invention to indicate specific flag information are merely examples, and the same information can be expressed using other binary codes, and such embodiments are also within the scope of the present invention.

[0077] FIG. 3 is a flowchart illustrating a method for transmitting transform unit information using a quadtree structure according to another embodiment of the present invention.

[0078] Referring to FIG. 3, it is determined whether the size of the current conversion unit is larger than the minimum conversion unit (step S300).

[0079] Currently, the size of the transform unit can be calculated based on a coefficient indicating transform depth information (trafoDepth) or maximum transform unit size information, or can be calculated directly using a coefficient indicating block size information.

[0080] The integrated code block flag information is transmitted only if the size is larger than the minimum transform unit, and if the size is the minimum transform unit, the integrated code block flag information is not transmitted and each code block flag (cbf_y, cbf_u, cbf_v) can be directly coded in the current transform unit (step S340).

[0081] The code block flag cbf_luma or cbf_y may indicate whether there are one or more non-zero transform coefficients among the transform coefficient values obtained by converting the luminance signal in the current transform unit, cbf_cb may indicate whether there are one or more non-zero transform coefficients among the transform coefficient values obtained by converting the chrominance signal cb in the current transform unit, and cbf_cr may indicate whether there are one or more non-zero transform coefficients among the transform coefficient values obtained by converting the chrominance signal cr in the current transform unit.

[0082] If the size of the current transform unit is larger than the minimum transform unit, the integrated code block flag is coded at the current transform depth (step S310).

[0083] The integrated code block flag is a flag indicating whether or not there are transform quantization coefficients for the luminance signal and the chrominance signal. If the value is not 0, it means that there are one or more transform coefficients that are not 0 in the corresponding transform unit.

[0084] The integration code flag can be used as a flag that represents the Y / Cb / Cr code block flags. If any one of the Y / Cb / Cr cbfs is not 0, the integration code flag can be expressed as a non-zero value, and if all of the Y / Cb / Cr cbfs are 0, the integration code flag can be expressed as 0.

[0085] The transform depth at which the integrated code block flag is used may be fixedly predetermined, or the transform depth at which the integrated code block flag can be applied may be adaptively changed, and the applicability of the integrated code block flag may be varied for various units such as a sequence, a picture, a slice, etc. Information for adaptively changing the transform depth may be included in a Sequence Parameter Set (SPS), a Picture Parameter Set (PPS), or a Slice Header.

[0086] The division information flag is coded at the current transform depth according to the integrated code block flag information (step S320).

[0087] Currently, information about whether a transform unit is split can be transmitted via a syntax element split_transform_flag. Hereinafter, in the embodiments of the present invention, the term split information flag may be used to have the same meaning as split_transform_flag.

[0088] For example, if the current transform unit is to be split, the value of the split information flag can be set to a value other than 0, and if the current transform unit is not to be split, the value of the split information flag can be set to 0. The binary codes for representing syntax elements and syntax element information used in the embodiments of the present invention are merely examples, and other syntax elements and binary codes for other syntax elements can be used as long as they do not deviate from the essence of the present invention.

[0089] In the block information transmission method using a quadtree according to an embodiment of the present invention, division information can be transmitted differently according to the integration code flag.

[0090] When the integrated code block flag is not 0 and the current transform unit is not divided into lower transform units, the partition information flag value may be 0. When the integrated code block flag is not 0 and the current transform unit is divided into lower transform units, the partition information flag value may be non-zero. In addition, when the integrated code block flag is 0, partition information for the current transform unit is not additionally transmitted, thereby avoiding transmission of unnecessary partition information. The integrated code block flag and the partition information flag may be combined and jointly coded. When the integrated code block flag and the partition information flag are jointly coded, the procedures of steps S300 to S320 may be changed. When the integrated code block flag is applied, the coding method determines which information needs to be coded among cbf_y, cbf_u, cbf_v, and split_flag in the current transform unit, and then expresses necessary syntax element information as predetermined pattern information. Based on the pattern information, each code block flag (cbf_y, cbf_u, cbf_v) and partition information flag (split_transform_flag) in the current transform unit may be expressed. The encoding method using the integrated code flag will be described in detail below.

[0091] It is determined whether the current transform unit is to be further divided (step S330).

[0092] If the transform unit is further divided, the process returns to step S300 to determine whether the size of the divided transform unit is the smallest size transform unit. If the divided transform unit is the smallest size transform unit, the process returns to step S340 to immediately encode each transform coefficient information (cbf_y, cbf_u, cbf_v) existing in the current transform unit without transmitting the integrated code block flag information, and then terminate the procedure for encoding the transform unit information.

[0093] 4 to 6, a method for transmitting an integrated code block flag and a partition information flag based on a coding unit will be described. That is, transform coefficient information and partition information of a transform unit included in a coding unit can be transmitted for each coding unit. However, in the block information transmission method using a tree according to an embodiment of the present invention, it is also possible to transmit an integrated code block flag and a partition information flag for each transform unit.

[0094] FIG. 4 is a conceptual diagram illustrating a method for applying an integrated code block flag and a segmentation information flag according to another embodiment of the present invention.

[0095] Referring to Figure 4, the top and bottom parts of Figure 4 are conceptual diagrams illustrating a method for transmitting an integrated code block flag and a partition information flag when the current transform unit is an AZCB (All Zero Coefficient Block) in which no transform coefficients exist and the integrated code block flag is applied only to the highest transform block.

[0096] Hereinafter, in an embodiment of the present invention, an AZCB (All Zero Coefficient Block) in which no transform coefficient exists in the current transform unit may be referred to as a zero transform coefficient transform unit.

[0097] The top part of FIG. 4 shows a case where the size of the coding unit and the size of the highest-level transform unit are the same, and there are no transform coefficients included in the transform unit.

[0098] If the size of the coding unit and the size of the highest transform unit are the same and there are no transform coefficients included in the transform unit, no additional division is performed, so the integrated code block flag is set to 0 in the highest transform unit, and the size information and transform coefficient information of the current transform unit can be transmitted without transmitting the division information flag.

[0099] In other words, in the block information transmission method using a quad tree according to an embodiment of the present invention, a zero transform coefficient transform unit in which no transform coefficients exist is not divided into additional transform units, so that division information is unnecessary and no additional division information flag is transmitted.

[0100] The bottom part of FIG. 4 shows a case where the size of the coding unit is different from the size of the highest-level transform unit, and the transform coefficients included in the transform unit do not exist.

[0101] If the size of the highest transform unit is smaller than the size of the coding unit and all of the highest transform units included in the coding unit are zero transform coefficient transform units, the integrated code block flag is set to 0, and the size information and transform coefficient information of the current transform unit can be transmitted without transmitting the partition information flag.

[0102] FIG. 5 is a conceptual diagram illustrating a method for applying an integrated code block flag and a segmentation information flag according to another embodiment of the present invention.

[0103] Referring to Figure 5, the top and bottom parts of Figure 5 are conceptual diagrams illustrating a method for transmitting an integrated code flag and a split information flag when there are transform coefficients included in the current transform unit and the integrated code block flag is applied only to the highest transform block.

[0104] The top part of Figure 5 shows a case where the size of the coding unit and the size of the top-level transform unit are the same, transform coefficients exist, and the top-level transform unit is not split into additional transform units.

[0105] In the highest transform unit, the integrated code block flag can be set to a value other than 0, the partition information flag can be transmitted as 0, and the partitionability information and transform coefficient information of the current transform unit can be transmitted.

[0106] The bottom part of FIG. 5 shows a case where the size of the coding unit and the size of the top-level transform unit are the same, transform coefficients exist, and the top-level transform unit is divided into additional transform units.

[0107] In the case of a block in which the size of the highest transform unit is the same as the size of the coding unit and a transform coefficient exists in at least one transform unit among the lower-division transform units, the integration code flag is set to a non-zero value in the highest transform unit and the division information flag is transmitted as a non-zero value to indicate whether a transform coefficient exists in the transform unit included in the current coding unit and the division status.

[0108] FIG. 6 is a conceptual diagram illustrating a method for applying an integrated code block flag and a segmentation information flag according to another embodiment of the present invention.

[0109] Referring to FIG. 6, a case is shown in which the size of the highest transform unit is smaller than the coding unit and transform coefficients exist.

[0110] If the size of the highest transform unit is smaller than the coding unit and transform coefficients exist, the integrated code block flag is sent with a non-zero value and the transform unit is divided into transform units smaller in size than the current coding unit, so that the division information of the transform units included in the current coding unit can be indicated without sending the division information flag.

[0111] FIG. 7 is a conceptual diagram illustrating how an integrated code block flag and a partition information flag are applied differently depending on depth information of a transform unit according to another embodiment of the present invention.

[0112] In FIG. 7, the integrated code block flag and the division information flag can be transmitted based on the transform unit.

[0113] Referring to the top of FIG. 7, it is shown that the unified code flag is applied only when the depth of the transform unit is 0, that is, only to the top-level transform unit.

[0114] When the depth of the transform unit is 0, i.e., when the merged code block flag and the split information flag are applied only to the top-level coding unit, the merged code block flag can be sent based on whether transform coefficients exist in higher transform units relative to the top-level transform unit, and the split information flag can be sent based on whether the top-level transform unit is additionally split. In the upper part of Figure 7, since transform coefficients exist based on the top-level transform unit, the merged code block flag can be set to a non-zero value (cbf_yuv[depth]!=0) and the split information flag can be set to 1 (split_transform_flag[depth]!=0).

[0115] Referring to the bottom of FIG. 7, it is shown that the integrated code block flag and the partition information flag are applied up to a depth of 1 in the transform unit.

[0116] In the bottom block of Figure 7, when the depth of the transform unit is 0, the integrated code block flag is set to a value other than 0 because transform coefficients exist, and the partition information flag can be set to 1 because it is divided into additional lower transform units.

[0117] When the transform depth is 1, the merge code flag and split information flag can be applied again to each transform unit. For example, when the first transform unit 700, second transform unit 710, third transform unit 720, and fourth transform unit 730 are defined based on the z scan direction, the first transform unit 700 to the third transform unit 720 transmit the merge code block flag as 0 because they have no transform coefficients, and do not transmit the split information flag because all of the transform coefficients are 0 and they will not be split into additional transform units (cbf_yuv[depth]=0, split_transform_flag[depth]=0). The fourth transform unit 730 transmits the merge code flag as a non-zero value and the split information flag as 1 because it has transform coefficients and will be split into additional transform units (cbf_yuv[depth]!=0, split_transform_flag[depth]!=0).

[0118] Table 1 below shows the syntax for sending the integration code flag and the segmentation information flag.

[0119] [Table 1]

[0120] Referring to Table 1, the integrated code block flag and the division information flag can be expressed by the transform unit depth information in the transform tree syntax.

[0121] FIG. 8 is a conceptual diagram illustrating a process of decoding transform unit information in a quadtree structure according to another embodiment of the present invention.

[0122] The transform units shown on the left side of FIG. 8 indicate a case where the maximum transform unit size is 32×32 and the minimum transform unit size is 4×4.

[0123] The left side of Figure 8 is a block indicating the partitioning status of the current transform unit and whether or not transform coefficients exist, and the right side of Figure 8 is a tree structure showing how to respectively represent the integrated code block flag and the partition information flag at each depth of the transform unit.

[0124] In Figure 8, when the transform depth is 0, 800 indicates that cbf_yuv_flag is not 0, indicating that transform coefficients exist at transform unit depth 0, and split_transform_flag is 1, indicating that splitting will occur in lower transform units.

[0125] 8, for transform depth 1, 810, 820, 830, and 840 indicate information on whether transform coefficients exist in the transform units divided into transform unit depth 1 and whether the transform units of transform unit depth 1 are to be further divided. That is, since the first transform block 850 does not have any transform coefficients, it transmits the value of the integrated code block flag as 0 and does not transmit any additional partition information flags. The fourth transform block 860 is also the same as the first transform block, and since the second transform block 870 and the third transform block 880 have transform coefficients, it transmits the integrated code block flag as a non-zero value and transmits the partition information flag as 1 because they are to be divided into additional transform units.

[0126] Looking at the transform unit that has been additionally split based on the second transform block, if the current transform unit is not additionally split 880, cbf_y, cbf_u, and cbf_v of the current transform unit can each be transmitted, and if it is additionally split 890, the integrated code block flag information and split information flag for the current transform unit can be transmitted.

[0127] If the additionally divided transform unit is the smallest transform unit 895, the cbf_y, cbf_u, and cbf_v information of the smallest transform unit can be immediately transmitted.

[0128] As described above, in the block information transmission method using a quad tree according to another embodiment of the present invention and the apparatus using the method, the integrated code block flag and the partition information flag can be jointly coded.

[0129] By encoding each element of the integrated code block flag, cbf_y, cbf_u, and cbf_v, and the split_transform_flag indicating the split information, respectively, the integrated code block flag and the split information flag are combined and coded as a pattern, so that the same information can be transmitted with a smaller bit value.When joint coding is used, each element of the integrated code block flag, cbf_y, cbf_u, and cbf_v, and the split_transform_flag information indicating the split information can be combined and coded separately.

[0130] The integrated code block flag can be expressed as a single syntax element called cbf_yuv_split_flag, which is coded by combining the elements cbf_y, cbf_u, and cbf_v, which can be used to calculate the integrated code block flag, and the term "transform unit information combined flag" is also used to mean the same as cbf_yuv_split_flag.

[0131] Table 2 below is a table for performing joint coding for combining and transmitting the integration code flag and the division information flag.

[0132] [Table 2]

[0133] Referring to Table 2, the cases where each element of the integrated code block flag, cbf_y, cbf_u, and cbf_v, and the split_transform_flag indicating split information can be output can be defined by one table. For example, the transform unit information combination flag can encode the cases where each element of the integrated code block flag, cbf_y, cbf_u, and cbf_v, and the split_transform_flag indicating split information, can be output based on the pattern information.

[0134] For example, if cbf_u and cbf_v have already been coded in a transform unit of a higher unit, there is no need to code information about cbf_u and cbf_v in the lower transform unit, and if the current transform unit is the minimum coding unit, only information about cbf_y needs to be coded. In this case, only information about whether a luminance signal exists in the current transform unit can be coded via pattern 1. That is, the pattern of the current transform unit is 1, and information about whether a luminance signal exists in the current transform unit can be additionally transmitted.

[0135] As another example, if cbf_u and cbf_v have already been coded in a transform unit of a higher-level unit and the current transform unit is not the smallest-sized transform unit, information regarding whether a luminance signal exists in the current transform unit can be coded based on pattern 2. That is, the pattern of the current transform unit is 2, and information regarding whether a luminance signal exists in the current transform unit and whether the current transform unit is divided can be transmitted.

[0136] By using a pattern, it is possible to determine what information needs to be coded in the current transform unit and code only that information.Pattern information can be preferentially expressed as 4-bit information with cbf_y value as MSB, cbf_u as MSB-1, cbf_v as MSB-2, and split_flag as LSB, and flag patterns can also be binary coded using VLC code during subsequent coding.

[0137] Table 3 below shows the syntax structure of a transform unit information combination flag that is coded by combining an integration code flag and a division information flag.

[0138] [Table 3]

[0139] Referring to Table 3, a new syntax element, cbf_yuv_split_trans, can be added to the transform_tree syntax to represent luminance signal information, chrominance signal information, and split information in the current coding unit.

[0140] In a block information transmission method using a quadtree according to another embodiment of the present invention, the transform unit information joint flags of transform units of the same size existing at the same depth can be jointly coded again.

[0141] FIG. 9 is a flowchart showing a method for encoding transform coefficient information and partition information of a transform unit when a transform unit information combination flag is used.

[0142] Referring to FIG. 9, the pattern of the code block flag and the division information flag for which encoding is to be performed in transform units is encoded (step S900).

[0143] The pattern information of the code block flag and the division information flag can be coded based on Table 2.

[0144] Based on the coded pattern information, the corresponding code block flag and division information flag are coded (step S910).

[0145] Based on the coded pattern information, the values of the code block flag and division information flag corresponding to the corresponding pattern information are coded.

[0146] For example, if the pattern information is 2, information on whether a luminance signal exists in the current transform unit can be coded.

[0147] FIG. 10 is a conceptual diagram illustrating a method for combining and encoding an integration code flag and a division information flag according to another embodiment of the present invention, and integrating transform unit information of transform units existing at the same depth.

[0148] 10, each block represents a conversion unit, and the numbers written in each conversion unit represent the pattern information of the combination flag information. For convenience, in the blocks and the table described below, 0 means pattern 1, 1 means pattern 2, and 3 means pattern 4.

[0149] Referring to the left side of FIG. 10, the conversion unit is made up of four conversion units with pattern information 1, and referring to the right side of FIG. 10, the conversion unit is made up of four conversion units with pattern information 2, 4, 2, 1.

[0150] That is, in the upper transform unit, the pattern information of the lower transform unit can be combined again to generate one upper transform unit pattern information. Table 4 below shows the upper transform unit pattern information.

[0151] [Table 4]

[0152] Referring to Table 4, for the transform units on the left side of Figure 8, in the z scan direction, the first transform unit has a cbf_yuv_split_trans pattern value of 0, the second transform unit has a cbf_yuv_split_trans pattern value of 0, the third transform unit has a cbf_yuv_split_trans pattern value of 0, and the fourth transform unit has a cbf_yuv_split_trans pattern value of 0, and can have new pattern information 1. For the transform units on the left side of Figure 10, in the z scan direction, the first transform unit has a cbf_yuv_split_trans pattern value of 1, the second transform unit has a cbf_yuv_split_trans pattern value of 3, the third transform unit has a cbf_yuv_split_trans pattern value of 1, and the fourth transform unit has a cbf_yuv_split_trans pattern value of 0, and can have new pattern information 5.

[0153] Such higher-order transform block pattern information can also be defined and used as a new syntax element in the transform_tree syntax.

[0154] FIG. 11 is a flowchart for decoding block information of a quadtree structure according to another embodiment of the present invention.

[0155] Referring to FIG. 11, the integrated code block flag information in the current transform unit is decoded (step S1100).

[0156] The division information flag is decoded based on the size information of the current transform unit and the integration code flag information (step S1110).

[0157] When the transform unit information combination flag (cbf_yuv_split_flag) that combines the above-mentioned integrated code block flag and split_transform_flag information is used, the processes of steps S1100 and S1110 can be changed. As described above in Table 2, the transform unit information combination flag information of the current transform unit is decoded, and information on whether a luminance signal and a chrominance signal exist in the current transform unit or are split can be additionally decoded based on the decoded pattern information.

[0158] FIG. 12 is a flowchart illustrating a method for decoding transform unit information combination flag information according to another embodiment of the present invention.

[0159] Referring to FIG. 12, pattern information is decoded based on the transform unit information combination flag information (step S1200).

[0160] Based on the decoded pattern information, the code block flag or division information flag information corresponding to the pattern is decoded (step S1210).

[0161] That is, the pattern information is provided based on Table 2, and the code block flag information and division flag information corresponding to the pattern information can be decoded.

[0162] Although the present invention has been described above with reference to the embodiments, those skilled in the art will understand that the present invention can be modified and changed in various ways without departing from the spirit and scope of the present invention as set forth in the claims.

Claims

1. 1. A method of decoding information for use in video decoding, comprising: decoding first code block flag information for the coding unit; determining whether to decode a partition information flag based on the first code block flag information and the size information of the transform unit; When the partition information flag is decoded, if the transform unit is not further divided based on the partition information flag, decoding second code block flag information for the transform unit; Equipped with If the partitioning information indicates that the transform unit is partitioned, the transform unit is partitioned into four sub-transform units; the size information indicates a size of the transform unit; If the value of the first code block flag information is equal to a predetermined value or if the size of the transform unit is equal to or smaller than a minimum transform unit size, the partition information flag is not decoded; a method for decoding information used in video decoding, wherein, when the size of the transform unit is equal to the minimum transform unit size, the partition information flag is not decoded and the second code block flag information of the transform unit is decoded.

2. The first code block flag information is an integrated code block flag, the second code block flag information is a code block flag of a luma component that indicates whether at least one non-zero transform coefficient of the luma component of the transform unit exists in the transform unit; The method of claim 1 , wherein the first code block flag information is decoded if the transform depth of the transform unit is equal to a predetermined value.

3. 3. The method of claim 2, wherein the predetermined value indicates that the transformation depth is a top-level transformation depth.

4. The method of claim 1 , wherein the first code block flag information applies only to a predetermined transform depth within the transform unit.

5. 1. A method of encoding information for use in video encoding, comprising: encoding the first code block flag information in an encoding unit; determining whether to encode a partition information flag based on the first code block flag information and size information of a transform unit; When the partition information flag is coded, if the transform unit is not further divided based on the partition information flag, coding second code block flag information of the transform unit; Equipped with If the partitioning information indicates that the transform unit is partitioned, the transform unit is partitioned into four sub-transform units; the size information indicates a size of a conversion unit; If the value of the first code block flag information is equal to a predetermined value or if the size of the transform unit is equal to or smaller than a minimum transform unit size, the partition information flag is not coded; a method for encoding information used in video encoding, wherein, when the size of the transform unit is equal to the minimum transform unit size, the second code block flag information of the transform unit is encoded without encoding the partition information flag.

6. The first code block flag information is an integrated code block flag, the second code block flag information is a code block flag of a luma component that indicates whether at least one non-zero transform coefficient of the luma component of the transform unit exists in the transform unit; The method of claim 5 , wherein the first code block flag information is encoded if the transform depth of the transform unit is equal to a predetermined value.

7. 7. The method of claim 6, wherein the predetermined value indicates that the transformation depth is a top-level transformation depth.

8. The method of claim 5 , wherein the first code block flag information applies only to a predetermined transform depth within the transform unit.

9. 6. The method of claim 5, wherein a bitstream is generated that includes the first codeblock flag information, the partition information flag, and the second codeblock flag information.

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