Video encoding / decoding method and apparatus

Abstract

The present application relates to a video decoding method, and a video decoding method according to an embodiment of the present application includes the steps of: determining a prediction mode of a current block based on at least one of a size of the current block; and generating a prediction block of the current block based on the determined prediction mode. The step of determining the prediction mode of the current block can be based on a comparison between the size of the current block and a predetermined value.

Description

Technical Field

[0001] This invention relates to an image encoding / decoding method and apparatus, and more particularly to an encoding / decoding method for predictive pattern information. Background Technology

[0002] In recent years, the demand for multimedia data such as video on the Internet has been increasing dramatically. However, the current development speed of channel bandwidth is insufficient to fully meet the rapidly increasing volume of multimedia data. Considering the above situation, the Video Coding Expert Group (VCEG) of the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) and the Moving Picture Expert Group (MPEG) of the International Organization for Standardization / International Electrotechnical Commission (ISO / IEC) developed the first version of the video compression standard, High Efficiency Video Coding (HEVC), in February 2014.

[0003] Video compression techniques include various methods such as intra-frame prediction, inter-frame prediction, transform, quantization, entropy coding, and loop filtering. Existing image encoding / decoding methods encode / decode prediction mode information used to indicate prediction modes according to different coding units, thus limiting improvements in encoding efficiency. Summary of the Invention

[0004] Technical issues

[0005] The main objective of this invention is to solve the existing problems described above and provide a more effective method for encoding and decoding prediction pattern information.

[0006] Technical solution

[0007] An image decoding method applicable to one embodiment of the present invention may include the following steps: determining a prediction mode for the current block based on the size of the current block; and generating a prediction block for the current block based on the determined prediction mode; wherein, in the step of determining the prediction mode for the current block, the prediction mode for the current block may be determined based on a comparison result between the size of the current block and a preset value.

[0008] In the above image decoding method, the step of determining the prediction mode of the current block can be performed without entropy decoding of the prediction mode information of the current block when the size of the current block is less than or equal to a preset value, and the prediction mode of the current block can be determined as the in-frame prediction mode.

[0009] In the above image decoding method, the step of determining the prediction mode of the current block can be performed by entropy decoding of the prediction mode information of the current block when the size of the current block is greater than a preset value, and the prediction mode of the current block can be determined according to the prediction mode information of the current block obtained by entropy decoding.

[0010] In the above image decoding method, the step of determining the prediction mode of the current block can be performed without entropy decoding of the prediction mode information of the current block when the size of the current block is equal to a preset value, and the prediction mode of the current block can be determined as the in-frame prediction mode.

[0011] In the above image decoding method, the size of the current block may include at least one of the width and height of the current block.

[0012] An image encoding method applicable to one embodiment of the present invention may include the following steps: determining the prediction mode of the current block based on the size of the current block; and generating a bitstream based on the determination; wherein, the step of determining the prediction mode of the current block may determine whether or not to entropy encode the prediction mode information based on a comparison result between the size of the current block and a preset value.

[0013] In a computer-readable non-transitory recording medium containing a bitstream used in image decoding, an embodiment of the present invention is applicable. The bitstream may contain prediction mode information of the current block. In the image decoding, the prediction mode of the current block may be determined based on a comparison between the size of the current block and a preset value. If the size of the current block is less than or equal to the preset value, entropy decoding of the prediction mode information of the current block may not be performed, and the prediction mode of the current block may be determined as an in-frame prediction mode.

[0014] Technical effect

[0015] This invention can improve coding efficiency by reducing the amount of encoded information.

[0016] Furthermore, the performance of arithmetic coding and arithmetic decoding can be improved by effectively selecting the context model suitable for encoding or decoding predictive pattern information. Attached Figure Description

[0017] Figure 1 This is a block diagram illustrating an image encoding apparatus to which one embodiment of the present invention is applied.

[0018] Figure 2 This is a block diagram illustrating an image decoding apparatus to which one embodiment of the present invention is applied.

[0019] Figure 3 It is the syntax and semantics used to describe the decoding of prediction pattern information.

[0020] Figure 4 This is a flowchart illustrating the method of determining the prediction mode of the current block based on the size of the current block.

[0021] Figure 5 This is a flowchart illustrating the method of determining the prediction mode of the current block based on the size of the current block.

[0022] Figure 6 This is a flowchart illustrating the entropy encoding / decoding method for prediction pattern information based on the size of the current block.

[0023] Figure 7 This is a flowchart illustrating the entropy encoding / decoding method for prediction pattern information based on the size of the current block.

[0024] Figure 8 This is a flowchart illustrating the entropy encoding / decoding method for prediction pattern information based on the size of the current block.

[0025] Figure 9 This is a flowchart illustrating the entropy encoding / decoding method for prediction pattern information based on the size of the current block.

[0026] Figure 10 This is a flowchart illustrating a method for determining the prediction mode of the current block based on the distance between the current image and the reference image.

[0027] Figure 11 This is a flowchart illustrating a method for determining the prediction mode of the current block based on the distance between the current image and the reference image.

[0028] Figure 12 This is a flowchart illustrating an entropy encoding / decoding method for predictive pattern information based on the distance between the current image and a reference image.

[0029] Figure 13 This is a flowchart illustrating an entropy encoding / decoding method for predictive pattern information based on the distance between the current image and a reference image.

[0030] Figure 14 This is a flowchart illustrating an entropy encoding / decoding method for predictive pattern information based on the distance between the current image and a reference image.

[0031] Figure 15 This is a flowchart illustrating an image decoding method applicable to one embodiment of the present invention.

[0032] Figure 16 This is a flowchart illustrating an image decoding method applicable to one embodiment of the present invention.

[0033] Figure 17 This is a flowchart illustrating an image encoding method applicable to one embodiment of the present invention.

[0034] Figure 18 This is a flowchart illustrating an image encoding method applicable to one embodiment of the present invention.

[0035] Preferred Implementation

[0036] This invention can be modified in various ways and has many different embodiments. Specific embodiments will be illustrated and described in detail below. However, the following content is not intended to limit the invention to a particular implementation, but should be understood to include all modifications, equivalents, and substitutions within the scope of the invention's concept and technology. Similar reference numerals are used for similar constituent elements in the description of the various figures.

[0037] In describing different constituent elements, terms such as "first" and "second" may be used, but the constituent elements are not limited by these terms. These terms are merely used to distinguish one constituent element from others. For example, without departing from the scope of the claims, a first constituent element may be named a second constituent element, and similarly, a second constituent element may be named a first constituent element. The term "and / or" includes a combination of multiple related descriptions or one of multiple related descriptions.

[0038] When a constituent element is described as being "connected" or "in contact" with other constituent elements, it should be understood that it can not only be directly connected or in contact with the aforementioned other constituent elements, but also that other constituent elements may exist between the two. Conversely, when a constituent element is described as being "directly connected" or "directly in contact" with other constituent elements, it should be understood that no other constituent elements exist between the two.

[0039] The terminology used in this application is for illustrative purposes only and is not intended to limit the invention. Singular statements also have plural meanings unless the context clearly indicates otherwise. In this invention, terms such as “~comprises~” or “~consisting of~” are merely to indicate the presence of features, numbers, steps, actions, constituent elements, components, or combinations thereof described in the specification, and should not be construed as excluding the possibility of one or more other features, numbers, steps, actions, constituent elements, components, or combinations thereof being present or added.

[0040] The embodiments to which the present invention applies will now be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals will be used for the same constituent elements in the drawings, and repeated descriptions of the same constituent elements will be omitted.

[0041] Figure 1 This is a block diagram illustrating an image encoding apparatus to which one embodiment of the present invention is applied.

[0042] See Figure 1 The image encoding apparatus 100 may include an image segmentation unit 101, an intra-frame prediction unit 102, an inter-frame prediction unit 103, a subtraction unit 104, a transformation unit 105, a quantization unit 106, an entropy encoding unit 107, an inverse quantization unit 108, an inverse transformation unit 109, an addition unit 110, a filtering unit 111, and a memory 112.

[0043] Figure 1 The various components illustrated are shown separately to illustrate different features and functions of the image encoding apparatus, and do not represent that each component is composed of separate hardware or software units. That is, although the various components are listed for ease of explanation, at least two components can be combined into one component, or a component can be divided into multiple components to perform corresponding functions. The embodiments where the various components are integrated or separated as described above are included within the scope of the claims of this invention without departing from the essence of the invention.

[0044] Furthermore, some constituent elements may not be essential for performing the essential functions of this invention, but rather optional elements used to improve performance. This invention may include only the constituent parts essential for realizing the essence of the invention, excluding those merely used to improve performance, and structures including essential constituent elements other than optional elements used to improve performance are also included within the scope of the claims of this invention.

[0045] The image segmentation unit 100 can segment an input image into at least one block. The input image can be of various shapes and sizes, such as an image, strip, parallel block, or fragment. A block can refer to a coding unit (CU), prediction unit (PU), or transform unit (TU). The segmentation can be performed based on at least one of quadtree, binary tree, and ternary tree segmentation. A quadtree segmentation divides a parent block into four child blocks, each half the width and height of the parent block. A binary tree segmentes a parent block into two child blocks, each half the width or height of the parent block. A ternary tree segmentation divides the parent block into three child blocks. For example, these three child blocks can be obtained by dividing the parent block in a 1:2:1 ratio. By performing segmentation based on a binary tree as described above, the blocks can have not only square shapes but also non-square shapes.

[0046] Prediction units 102 and 103 may include an inter-frame prediction unit 103 for performing inter-frame prediction and an intra-frame prediction unit 102 for performing intra-frame prediction. After deciding whether to perform inter-frame or intra-frame prediction on a prediction unit, specific information (e.g., intra-frame prediction mode, motion vector, reference image, etc.) can be determined based on the different prediction methods. In this case, the processing unit used to perform prediction can be different from the processing unit used to determine the prediction method and specific content. For example, the prediction method and prediction mode can be determined at the prediction unit level, while prediction can be performed at the transformation unit level.

[0047] The residual value (residual block) between the generated prediction block and the original block can be input to the transform unit 105. Furthermore, prediction mode information and motion vector information used during the prediction process can be encoded together with the residual value in the entropy coding unit 107 before being transmitted to the decoder. When using a specific coding mode, the original block can also be directly encoded and transmitted to the decoding unit, without generating a prediction block through the prediction units 102 and 103.

[0048] The intra-frame prediction unit 102 can generate prediction blocks based on pixel information within the current image, i.e., reference pixel information surrounding the current block. When the prediction mode of the surrounding blocks of the current block for which intra-frame prediction needs to be performed is inter-frame prediction, reference pixels contained in the surrounding blocks for which inter-frame prediction has been applied can be replaced with reference pixels in other surrounding blocks for which intra-frame prediction has been applied. That is, if reference pixels are unavailable, they can be used after replacing unavailable reference pixel information with at least one of the available reference pixels.

[0049] In intra-frame prediction, the prediction mode can include a directional prediction mode that uses reference pixel information based on the prediction direction, and a non-directional mode that does not use directional information when performing prediction. The mode used to predict luminance information can be different from the mode used to predict chromatic difference information. In order to predict chromatic difference information, the intra-frame prediction mode information used when predicting luminance information or the predicted luminance signal information can be used.

[0050] The in-frame prediction unit 102 may include an adaptive intra-smoothing (AIS) filter, a reference pixel interpolation unit, and a mean (DC) filter. The adaptive intra-smoothing (AIS) filter is used to filter the reference pixels of the current block, and its application can adaptively determine whether to apply the filter based on the prediction mode of the current prediction unit. When the prediction mode of the current block is a mode that does not perform adaptive intra-smoothing (AIS) filtering, the adaptive intra-smoothing (AIS) filter may not be applied.

[0051] When the intra-prediction mode of the prediction unit is a prediction unit that performs intra-prediction based on the pixel value interpolated from the reference pixel, the reference pixel interpolation unit of the intra-prediction unit 102 can generate a reference pixel at a fractional unit position by interpolating the reference pixel. When the prediction mode of the current prediction unit is a prediction mode that generates a prediction block without interpolating the reference pixel, interpolation of the reference pixel can be omitted. When the prediction mode of the current block is the mean (DC) mode, the mean (DC) filter can generate a prediction block by filtering.

[0052] The inter-frame prediction unit 103 generates prediction blocks using the reconstructed reference image stored in the memory 112 and motion information. The motion information may include, for example, motion vectors, reference image indexes, list 1 prediction flags, and list 0 prediction flags.

[0053] A residual block can be generated, which contains residual information about the difference between the prediction unit generated in prediction units 102 and 103 and the original block of the prediction unit. The generated residual block can be input into the transformation unit 130 for transformation.

[0054] The inter-frame prediction unit 103 can derive prediction blocks based on information from at least one of the previous or next images of the current image. Alternatively, it can derive prediction blocks of the current block based on information from a portion of the currently encoded region within the current image. The inter-frame prediction unit 103, according to one embodiment of the present invention, may include a reference image interpolation unit, a motion prediction unit, and a motion compensation unit.

[0055] In the reference image interpolation unit, reference image information can be received from memory 112 and pixel information of integer pixels or less can be generated in the reference image. For luminance pixels, an 8-tap interpolation filter based on discrete cosine transform (DCT-based Interpolation Filter) can be used, where the filter coefficients are modified to generate pixel information of integer pixels or less in 1 / 4 pixel units. For chrominance pixels, a 4-tap interpolation filter based on discrete cosine transform (DCT-based Interpolation Filter) can be used, where the filter coefficients are modified to generate pixel information of integer pixels or less in 1 / 8 pixel units.

[0056] The motion prediction unit can perform motion prediction based on a reference image interpolated by the reference image interpolation unit. Various methods can be used to calculate motion vectors, such as the Full Search-based Block Matching Algorithm (FBMA), the Three-Step Search (TSS), and the New Three-Step Search Algorithm (NTS). Motion vectors can be based on interpolated pixels and have motion vector values ​​in 1 / 2 or 1 / 4 pixel units. In the motion prediction unit, prediction blocks for the current prediction unit can be predicted using different motion prediction methods. These methods include skipping, merging, and Advanced Motion Vector Prediction (AMVP).

[0057] The haircutting calculation unit 104 generates a residual block for the current block by performing an addition operation on the block that needs to be encoded and the prediction block generated in the in-frame prediction unit 102 or the inter-frame prediction unit 103.

[0058] The transform unit 105 can transform the residual block containing residual data using transform methods such as Discrete Cosine Transform (DCT), Discrete Sine Transform (DST), and Karhunen-Loeve Transform (KLT). In this case, the transform method can be determined based on the intra-prediction mode of the prediction unit used to generate the residual block. For example, based on the intra-prediction mode, Discrete Cosine Transform (DCT) can be used in the horizontal direction, while Discrete Sine Transform (DST) can be used in the vertical direction.

[0059] The quantization unit 106 can quantize the values ​​that have been transformed into frequency regions in the transformation unit 105. The quantization coefficients can be changed according to the block or according to the importance of the image. The values ​​calculated in the quantization unit 106 can be provided to the inverse quantization unit 108 and the entropy coding unit 107.

[0060] The aforementioned transformation unit 105 and / or quantization unit 106 may be selectively included in the image coding apparatus 100. That is, the image coding apparatus 100 may perform at least one of transformation or quantization on the residual data of the residual block, or it may skip transformation and quantization and encode the residual block. Even if neither transformation nor quantization is performed in the image coding apparatus 100, the block input to the entropy coding unit 107 is generally referred to as a transformed block. The entropy coding unit 107 performs entropy coding on the input data. Entropy coding can use various coding methods such as Exponential Golomb code, Context-Adaptive Variable Length Coding (CAVLC), and Context-Adaptive Binary Arithmetic Coding (CABAC).

[0061] The entropy coding unit 107 can encode various types of information, such as coefficient information of the transform block, block type information, prediction mode information, segmentation unit information, prediction unit information, transmission unit information, motion vector information, reference frame information, block interpolation information, and filtering information. The coefficients of the transform block can be encoded in sub-block units within the transform block.

[0062] To encode the coefficients of the transform block, several syntax elements can be used, such as Last_sig (indicating the position of the first non-zero coefficient in the reverse scan order), Coded_sub_blk_flag (indicating whether the sub-block contains at least one non-zero coefficient), Sig_Coeff_flag (indicating whether a coefficient is non-zero), Abs_greater1_flag (indicating whether the absolute value of a coefficient is greater than 1), Abs_greater2_flag (indicating whether the absolute value of a coefficient is greater than 2), and Sign_flag (indicating the sign of a coefficient). The remaining values ​​of coefficients not encoded using the above syntax elements can be encoded using the remaining_coeff syntax element.

[0063] In the inverse quantization unit 108 and the inverse transform unit 109, the values ​​quantized in the quantization unit 106 are inverse quantized, and the values ​​transformed in the transform unit 105 are inverse transformed. The residual values ​​generated in the inverse quantization unit 108 and the inverse transform unit 109 can be merged with the prediction units predicted by the motion estimation unit, motion compensation unit, and in-frame prediction unit 102 included in the prediction units 102 and 103 to generate a reconstructed block. The addition unit 110 generates the reconstructed block by performing an addition operation on the prediction blocks generated in the prediction units 102 and 103 and the residual blocks generated by the inverse transform unit 109.

[0064] The filtering unit 111 may include at least one of a deblocking filter, an offset correction unit, and an adaptive loop filter (ALF).

[0065] Deblocking filters can remove block distortion caused by boundaries between blocks in a reconstructed image. To determine whether deblocking is necessary, the pixels contained in several columns or rows within a block can be used as a basis to determine whether a deblocking filter should be applied to the current block. When applying a deblocking filter to a block, a strong filter or a weak filter can be used depending on the required deblocking filtering intensity. Furthermore, when applying a deblocking filter, horizontal and vertical filtering can be processed in parallel while performing vertical and horizontal filtering.

[0066] The offset correction unit can correct the offset between the deblocked image and the original image on a pixel-by-pixel basis. To perform offset correction on a specific image, one can divide the pixels contained in the image into a certain number of regions, determine the regions that need to be offset, and apply the offset to the corresponding regions, or apply the offset while taking into account the edge information of each pixel.

[0067] Adaptive Loop Filtering (ALF) is performed based on a comparison between the filtered reconstructed image and the original image. After dividing the pixels in the image into specific groups, it can be determined which filter should be applied to the corresponding group, thus performing different filters in each group. For information related to whether ALF is applicable, the luminance signal can be transmitted according to each coding unit (CU), and the shape and filtering coefficients of the applicable ALF can be changed according to each block. Furthermore, regardless of the characteristics of the target block, an ALF of the same shape (fixed shape) can be applied.

[0068] The memory 112 can store the reconstructed blocks or images calculated by the filtering unit 111, and the stored reconstructed blocks or images can be provided to the prediction units 102 and 103 when performing inter-screen prediction.

[0069] Next, an image decoding apparatus to which one embodiment of the present invention is applied will be described with reference to the accompanying drawings. Figure 2 This is a block diagram illustrating an image decoding apparatus 200 to which one embodiment of the present invention is applied.

[0070] See Figure 2 The image decoding device 200 may include an entropy decoding unit 201, an inverse quantization unit 202, an inverse transform unit 203, an addition unit 204, a filtering unit 205, a memory 206, and prediction units 207 and 208.

[0071] When the image bitstream generated by the image encoding device 100 is input into the image decoding device 200, the input bitstream can be decoded in the reverse order of the process performed by the image encoding device 100.

[0072] The entropy decoding unit 201 can perform entropy decoding in the reverse order of the entropy encoding performed in the entropy encoding unit 107 of the image coding apparatus 100. For example, it can use various methods corresponding to those performed in the image encoder, such as Exponential Golomb code, Context-Adaptive Variable Length Coding (CAVLC), and Context-Adaptive Binary Arithmetic Coding (CABAC). The entropy decoding unit 201 can decode the syntax elements described above, namely Last_sig, Coded_sub_blk_flag, Sig_coeff_flag, Abs_greater1_flag, Abs_greater2_flag, Sign_flag, and remaining_coeff. Furthermore, the entropy decoding unit 201 can decode information related to intra-frame prediction and inter-frame prediction performed in the image coding apparatus 100.

[0073] The inverse quantization unit 202 generates a transform block by performing inverse quantization on the quantized transform block. According to... Figure 1 The inverse quantization unit 108 in the middle works in essentially the same way.

[0074] The inverse transform unit 203 generates a residual block by performing an inverse transform on the transform block. At this time, the transform method can be determined based on information related to the prediction method (inter-frame or intra-frame prediction), the block size and / or shape, and the intra-frame prediction mode. Figure 1 The inverse transformation unit 109 in the middle works in essentially the same way.

[0075] The addition unit 204 generates a reconstruction block by performing an addition operation on the prediction blocks generated in the in-frame prediction unit 207 or the inter-frame prediction unit 208 and the residual blocks generated by the inverse transformation unit 203. Figure 1 The addition unit 110 in the middle works in essentially the same way.

[0076] The filter unit 205 is used to reduce various types of noise generated in the reconstruction block.

[0077] The filtering unit 205 may include a deblocking filter, an offset correction unit, and an adaptive loop filter (ALF).

[0078] Information related to whether a deblocking filter has been applied to a corresponding block or image can be received from the image encoding device 100, and information related to whether a strong or weak filter was applied when a deblocking filter was applied. The image decoding device 200 can receive the deblocking filter-related information provided by the image encoding device 100, and then perform deblocking filtering on the corresponding block in the image decoding device 200.

[0079] The offset correction unit can perform offset correction on the reconstructed image based on the type of offset correction applicable to the image during encoding and offset value information.

[0080] The adaptive loop filter (ALF) can be applied to the encoding unit based on information such as whether the ALF is applicable and the ALF coefficient information provided from the image encoding apparatus 100. The ALF information described above can be provided in a manner included in a specific parameter set. The filtering unit 205 follows the same procedure as... Figure 1 The filtering section 111 in the middle works in essentially the same way.

[0081] The memory 206 stores the reconstructed blocks generated by the addition unit 204. According to... Figure 1 The memory 112 in the middle works in essentially the same way.

[0082] Prediction units 207 and 208 can generate prediction blocks based on prediction blocks generated from prediction blocks provided by entropy decoding unit 201 and previously decoded blocks or image information provided by memory 206.

[0083] Prediction units 207 and 208 may include an intra-frame prediction unit 207 and an inter-frame prediction unit 208. Although not shown separately, prediction units 207 and 208 may also include a prediction unit determination unit. The prediction unit determination unit can receive various types of information input from the entropy decoding unit 201, such as prediction unit information, prediction mode information of the intra-frame prediction method, and motion prediction-related information of the inter-frame prediction method, and distinguish prediction units from the current decoding unit, thereby determining whether the prediction unit performs inter-frame prediction or intra-frame prediction. The inter-frame prediction unit 208 may use the information required for inter-frame prediction of the current prediction unit provided by the image coding apparatus 100, and perform inter-frame prediction on the current prediction unit based on information contained in at least one of the previous or next images of the current image containing the current prediction unit. Alternatively, it may perform inter-frame prediction based on information of a reconstructed portion of the current image containing the current prediction unit.

[0084] To perform inter-frame prediction, the motion prediction method of the prediction unit contained in the corresponding coding unit can be determined based on the coding unit. This method can be Skip Mode, Merge Mode, or Advanced Motion Vector Prediction Mode (AMVP Mode).

[0085] The in-frame prediction unit 207 generates prediction blocks using the reconstructed pixels surrounding the blocks that need to be encoded in the current period.

[0086] The in-frame prediction unit 207 may include an adaptive intra-smoothing (AIS) filter, a reference pixel interpolation unit, and a mean (DC) filter. The adaptive intra-smoothing (AIS) filter is used to filter the reference pixels of the current block, and its application can be adaptively determined based on the prediction mode of the current prediction unit. Adaptive intra-smoothing (AIS) filtering can be performed on the reference pixels of the current block using the prediction mode of the prediction unit provided from the image coding apparatus 100 and the adaptive intra-smoothing (AIS) filter information. When the prediction mode of the current block is a mode that does not perform adaptive intra-smoothing (AIS) filtering, the adaptive intra-smoothing (AIS) filter may not be applied.

[0087] When the prediction mode of the prediction unit is a prediction unit that performs intra-frame prediction based on the pixel value interpolated from the reference pixel, the reference pixel interpolation unit of the intra-frame prediction unit 207 can generate a reference pixel at a fractional unit position by interpolating the reference pixel. The generated reference pixel at the fractional unit position can be used as the prediction pixel for the pixel in the current block. When the prediction mode of the current prediction unit is a prediction mode that generates a prediction block without interpolating the reference pixel, the reference pixel can be generated without interpolation. When the prediction mode of the current block is the mean (DC) mode, the mean (DC) filter can generate the prediction block by filtering.

[0088] The prediction unit 207 in the picture is in accordance with... Figure 1 The in-screen prediction unit 102 works in essentially the same way.

[0089] The inter-frame prediction unit 208 generates inter-frame prediction blocks using reference images stored in the memory 206 and motion information. Figure 1 The inter-image prediction unit 103 in the middle works in essentially the same way.

[0090] Next, various embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0091] This specification provides a method for effectively encoding / decoding prediction pattern information of the current block.

[0092] Figure 3 It is the syntax and semantics used to describe the decoding of prediction pattern information.

[0093] See Figure 3 When the current slice is not an I-slice (slice_type != I) and the current coding unit (CU) is not in skip mode (cu_skip_flag[x0][y0] == 0), entropy decoding can be performed on the prediction mode information (pred_mode_flag).

[0094] Specifically, a value of 0 for the prediction mode information (pred_mode_flag) indicates inter-frame prediction mode (MODE_INTER), while a value of 1 indicates intra-frame prediction mode (MODE_INTRA). Furthermore, the absence of the prediction mode information (pred_mode_flag) can be considered as intra-frame prediction mode (MODE_INTRA).

[0095] The encoding / decoding method for predictive pattern information applicable to one embodiment of the present invention can be determined based on the size of the current block. The size of the current block can refer to at least one of the width, height, or area of ​​the current block.

[0096] As the size of the current block increases, there is a statistically significant increase in the probability of performing inter-frame prediction rather than intra-frame prediction. Considering the characteristics described above, the prediction mode for the current block can be determined based on its size.

[0097] Figure 4 as well as Figure 5 This is a flowchart illustrating the method of determining the prediction mode of the current block based on the size of the current block.

[0098] See Figure 4 When the size of the current block is greater than or equal to a preset value (S401-Yes), the prediction mode of the current block can be determined as the inter-frame prediction mode (S402). However, when the size of the current block is less than the preset value (S401-No), the prediction mode of the current block can be determined based on the prediction mode information obtained from the bitstream (S402).

[0099] That is, in Figure 4When the size of the current block is greater than or equal to a preset value (S401-Yes), the prediction mode of the current block can be implicitly determined as inter-frame prediction without obtaining prediction mode information.

[0100] Figure 5 and Figure 4 The difference is that when the size of the current block is below a certain value (S501 - Yes), the prediction mode of the current block can be determined as the in-frame prediction mode (S502). However, when the size of the current block is greater than a preset value (S501 - No), the prediction mode of the current block can be determined based on the prediction mode information obtained from the bit stream (S503).

[0101] That is, in Figure 5 When the size of the current block is below a preset value (S501-Yes), the prediction mode of the current block can be implicitly determined as in-frame prediction without obtaining prediction mode information.

[0102] In addition, Figure 5 The pre-defined value can be the minimum size of the coding block. That is, when the current block size is the minimum size of the coding block, the prediction mode of the current block can be implicitly determined to be in-frame prediction without obtaining prediction mode information. Here, the coding block can be a coding unit, and the minimum size of the coding block can be 4×4. As an example, when the current block size is 4×4, the prediction mode of the current block can be implicitly determined to be in-frame prediction without obtaining prediction mode information. Conversely, when the current block size is not 4×4, the prediction mode of the current block can be determined based on the prediction mode information obtained from the bitstream.

[0103] That is, when the width or height of the current block is less than a preset value, the prediction mode of the current block can be implicitly determined as in-frame prediction without entropy decoding of the prediction mode information.

[0104] Table 1 below is an example of an entropy encoding method for predictive pattern information based on the current block size, as described above.

[0105] Table 1

[0106]

[0107]

[0108] In Table 1, entropy decoding can be performed on the prediction mode information when the size of the current block is not 4×4, while entropy decoding will not be performed on the prediction mode information when the size of the current block is not 4×4.

[0109] That is, when the width and height of the current block are equal to the preset values, the prediction mode of the current block can be implicitly determined as in-frame prediction without entropy decoding of the prediction mode information.

[0110] Figure 6 as well as Figure 7 This is a flowchart illustrating the entropy encoding / decoding method for prediction pattern information based on the current block size. (See also...) Figure 3 The explanation assumes that a prediction mode value of 0 indicates inter-frame prediction mode (MODE_INTER), a prediction mode value of 1 indicates intra-frame prediction mode (MODE_INTRA), and the absence of prediction mode information is considered as intra-frame prediction mode (MODE_INTRA). Figure 6 as well as Figure 7 Please provide an explanation.

[0111] See Figure 6 When at least one of the width or height of the current block is greater than or equal to a preset value (S601-Yes), the prediction mode information of the current block can be entropy encoded / decoded (S602).

[0112] However, if at least one of the width or height of the current block is less than a preset value (S601-No), the prediction mode information of the current block cannot be regarded as an in-frame prediction mode because entropy encoding / decoding is not performed on the prediction mode information of the current block.

[0113] Table 2 below is an applicable reference. Figure 6 An embodiment of an entropy encoding method for predictive pattern information based on the size of the current block is described.

[0114] Table 2

[0115] coding_unit(x0,y0,cbWidth,cbHeight,treeType){ descriptor if (slice_type != I) { cu_skip_flag[x0][y0] ae(v) if(cu_skip_flag[x0][y0]==0&&(cbWidth≥64||cbHeight≥64)) pred_mode_flag ae(v) }

[0116] In Table 2, when the width or height of the current block is greater than or equal to a preset value (64), the prediction mode information can be entropy decoded, while in the opposite case, the prediction mode information will not be entropy decoded.

[0117] That is, when the width and height of the current block are less than the preset values, the prediction mode of the current block can be implicitly determined as in-frame prediction without entropy decoding of the prediction mode information.

[0118] Table 3 below is another embodiment of the entropy coding method for predictive pattern information based on the size of the current block.

[0119] Table 3

[0120]

[0121] In Table 3, when the width and height of the current block are greater than or equal to the preset value (128), the prediction mode information can be entropy decoded, while in the opposite case, the prediction mode information will not be entropy decoded.

[0122] That is, when the width or height of the current block is less than a preset value, the prediction mode of the current block can be implicitly determined as in-frame prediction without entropy decoding of the prediction mode information.

[0123] See Figure 7 When the area of ​​the current block is greater than or equal to a preset value (S701-Yes), the prediction mode information of the current block can be entropy encoded / decoded (S702).

[0124] However, when the area of ​​the current block is less than the preset value (S701-No), since the prediction mode information of the current block is not entropy encoded / decoded, the prediction mode information of the current block cannot be regarded as the in-frame prediction mode.

[0125] Table 4 below is an applicable reference. Figure 7 An embodiment of an entropy encoding method for predictive pattern information based on the size of the current block is described.

[0126] Table 4

[0127]

[0128]

[0129] In Table 4, the prediction mode information can be entropy decoded when the area of ​​the current block is greater than or equal to the preset value (8192), and will not be entropy decoded when the opposite is true.

[0130] That is, when the width or height of the current block is less than a preset value, the prediction mode of the current block can be implicitly determined as in-frame prediction without entropy decoding of the prediction mode information.

[0131] Figure 8 This is a flowchart illustrating the entropy encoding / decoding method for prediction pattern information based on the current block size. The prediction pattern information is entropy encoded / decoded using Context-Adaptive Binary Arithmetic Coding (CABAC), which can utilize a single context model.

[0132] See Figure 8 When the size of the current block is less than a preset value (S801-No), the probability of the initial context model of the prediction mode information can be increased (S802).

[0133] In step S802, the probability of the initial context model can be increased by a predefined value.

[0134] Alternatively, in step S802, the probability of the initial context model can be increased inversely proportional to the size of the current block. Alternatively, the probability of the initial context model can be decreased proportionally to the size of the current block.

[0135] This is because as the size of the current block decreases, the probability of performing intra-frame prediction increases. Therefore, the smaller the size of the current block, the higher the probability that the prediction mode information value is 1 (i.e., intra-frame prediction), while the larger the size of the current block, the higher the probability that the prediction mode information value is 0 (i.e., inter-frame prediction).

[0136] Furthermore, in the entropy decoding method for predicting pattern information, it is not necessary to execute... Figure 8 Instead of performing step S801, only step S802 is executed. Specifically, the size of the current block can be compared with a preset value, and the probability of the initial context model of the prediction mode information can be increased inversely proportional to the size of the current block.

[0137] Figure 9 This is a flowchart illustrating the entropy encoding / decoding method for prediction pattern information based on the size of the current block.

[0138] exist Figure 9 In this paper, a novel context model is proposed as an alternative to, for example, [the following is a separate, unrelated sentence:] Figure 8 The diagram illustrates how to increase the probability of the initial context model by adding predictive pattern information. Specifically, in... Figure 9 In the entropy encoding / decoding method for the predicted pattern information illustrated, two or more independent context models can be used.

[0139] See Figure 9 When the size of the current block is greater than or equal to a preset value (S901 - Yes), the first context model can be used to perform entropy encoding / decoding of the prediction mode information (S902). Conversely, when the size of the current block is less than a preset value (S901 - No), the second context model can be used to perform entropy encoding / decoding of the prediction mode information (S903).

[0140] The second context model can be a context model with a higher probability of predicting mode information value of 1 (i.e., in-frame prediction) compared to the first context model.

[0141] The encoding / decoding method for predictive mode information applicable to one embodiment of the present invention can be determined based on the distance between the current image and the reference image.

[0142] The distance (delta_poc) between the current image and the reference image can be induced by either Mathematical Formula 1 or Mathematical Formula 2 as shown below. delta_poc can be defined as the minimum absolute difference between the image sequence number (POC) of the current image and the image sequence number (POC) of the reference image.

[0143]

Mathematical Formula 1

[0144] delta_poc=abs(currPoc-refpoc(l0,0))

[0145]

Mathematical Formula 2

[0146]

[0147] In mathematical expressions 1 and 2, abs() is the function for calculating absolute values, currPoc is the image sequence number (POC) of the current image, and refpoc(l,i) can refer to the image sequence number (POC) of the image with the i-th reference index in the reference list l. Furthermore, ref_list(l) can refer to the set of indices of all reference images contained in the reference list l.

[0148] Furthermore, as the distance between the current image and the reference image increases, there is a statistically significant increase in the probability of performing intra-frame prediction rather than inter-frame prediction. Considering the properties described above, the prediction mode for the current block can be determined based on the distance between the current block and the reference image.

[0149] Figure 10 as well as Figure 11 This is a flowchart illustrating a method for determining the prediction mode of the current block based on the distance between the current image and the reference image.

[0150] See Figure 10When the distance between the current image and the reference image is greater than or equal to a preset value (S1001 - Yes), the prediction mode of the current block can be determined as the in-frame prediction mode (S1002). However, when the distance between the current image and the reference image is less than the preset value (S1001 - No), the prediction mode of the current block can be determined based on the prediction mode information obtained from the bitstream (S1003).

[0151] That is, in Figure 10 When the distance between the current image and the reference image is greater than or equal to a preset value (S1001-Yes), the prediction mode of the current block can be implicitly determined as in-frame prediction without obtaining prediction mode information.

[0152] Figure 11 and Figure 10 Unlike other methods, when the distance between the current image and the reference image is below a certain value (S1101 - Yes), the prediction mode of the current block can be determined as the inter-image prediction mode (S1102). However, when the distance between the current image and the reference image is greater than a preset value (S1101 - No), the prediction mode of the current block can be determined based on the prediction mode information obtained from the bitstream (S1103).

[0153] That is, in Figure 11 When the distance between the current image and the reference image is below a preset value (S1101-Yes), the prediction mode of the current block can be implicitly determined as inter-image prediction without obtaining prediction mode information.

[0154] Figure 12 as well as Figure 13 This is a flowchart illustrating an entropy encoding / decoding method for predicting pattern information based on the distance between the current image and a reference image. (See also...) Figure 3 The explanation assumes that a prediction mode value of 0 indicates inter-frame prediction mode (MODE_INTER), a prediction mode value of 1 indicates intra-frame prediction mode (MODE_INTRA), and the absence of prediction mode information is considered as intra-frame prediction mode (MODE_INTRA). Figure 12 Please provide an explanation.

[0155] See Figure 12 When the distance between the current image and the reference image is less than a preset value (S1201-No), the prediction mode information of the current block can be entropy encoded / decoded (S1202).

[0156] However, when the distance between the current block and the reference image is greater than or equal to a preset value (S1201-No), the prediction mode information of the current block cannot be regarded as an in-frame prediction mode because the prediction mode information of the current block will not be entropy encoded / decoded.

[0157] See Figure 13 When the distance between the current image and the reference image is greater than or equal to a preset value (S1301 - Yes), the probability of the initial context model of the prediction mode information can be increased (S1302). In step S1302, the probability of the initial context model can be increased according to a preset value.

[0158] Alternatively, in step S1302, the probability of the initial context model can be increased proportionally to the distance between the current image and the reference image.

[0159] This is because as the distance between the current image and the reference image increases, the probability of performing intra-frame prediction increases. Therefore, the smaller the distance between the current image and the reference image, the higher the probability of the prediction mode information value being 1 (i.e., intra-frame prediction), while the larger the distance between the current image and the reference image, the higher the probability of the prediction mode information value being 0 (i.e., inter-frame prediction).

[0160] Furthermore, in the entropy encoding / decoding method for predicting pattern information, it is not necessary to perform... Figure 13 Instead of performing step S1301, only step S1302 is executed. Specifically, instead of comparing the distance between the current image and the reference image with a preset value, the probability of the initial context model predicting the mode information can be increased proportionally to the distance between the current image and the reference image.

[0161] Figure 14 This is a flowchart illustrating an entropy encoding / decoding method for predictive pattern information based on the distance between the current image and a reference image.

[0162] exist Figure 14 In this paper, a novel context model is proposed as an alternative to, for example, [the following is a separate, unrelated sentence:] Figure 13 The diagram illustrates how to increase the probability of the initial context model by adding predictive pattern information. Specifically, in... Figure 14 In the entropy encoding / decoding method for the predicted pattern information illustrated, two or more independent context models can be used.

[0163] See Figure 14When the distance between the current image and the reference image is greater than or equal to a preset value (S1401 - Yes), the second context model can be used to perform entropy encoding / decoding of the prediction mode information (S1402). Conversely, when the distance between the current image and the reference image is less than a preset value (S1401 - No), the first context model can be used to perform entropy encoding / decoding of the prediction mode information (S1403).

[0164] The second context model can be a context model with a higher probability of predicting mode information value of 1 (i.e., in-frame prediction) compared to the first context model.

[0165] Furthermore, the encoding / decoding method for the prediction mode information can be determined by simultaneously considering the size of the current block and the distance between the current image and the reference image.

[0166] As an example, when the size of the current block is less than or equal to the first threshold and the distance between the current image and the reference image is greater than the second threshold, entropy encoding / decoding of the prediction mode information of the current block can be omitted. In the case described above, because entropy encoding / decoding of the prediction mode information of the current block is not performed, it cannot be considered as an in-frame prediction mode.

[0167] In addition, in Tables 1 to 4, Figure 6 , Figures 7 to 12 The text explains the case where the prediction mode information is not present, and it is considered an in-frame prediction mode. However, as shown in the reference... Figure 3 The explanation provided is that prediction mode information may not be considered as intra-frame prediction if it is not available. That is, when slice_type is I-Slice, the prediction mode is considered as intra-frame prediction; when slice_type is not I-Slice and cu_skip_flag is 1, it is considered as inter-frame prediction; and in other cases (i.e., when slice_type is not I-Slice and cu_skip_flag is 0), it can be considered as inter-frame prediction.

[0168] Table 5 below is an example of an entropy decoding method for prediction mode information based on the current block size, under the assumptions described above (i.e., considered as inter-frame prediction without signaling to pred_mode_flag).

[0169] Table 5

[0170]

[0171] In Table 5, when the width or height of the current block is less than the preset value (64), the prediction mode information can be entropy decoded, while in the opposite case, the prediction mode information will not be entropy decoded.

[0172] That is, when the width and height of the current block are greater than or equal to the preset values, the prediction mode of the current block can be implicitly determined as inter-frame prediction without entropy encoding / decoding the prediction mode information.

[0173] Table 6 below is another embodiment of the entropy decoding method for prediction mode information based on the current block size, under the assumptions described above (i.e., considered as inter-frame prediction without signaling to pred_mode_flag).

[0174] Table 6

[0175]

[0176]

[0177] In Table 6, when the width and height of the current block are less than the preset value (128), the prediction mode information can be entropy decoded, while in the opposite case, the prediction mode information will not be entropy decoded.

[0178] That is, when the width or height of the current block is greater than or equal to a preset value, the prediction mode of the current block can be implicitly determined as inter-frame prediction without entropy encoding / decoding the prediction mode information.

[0179] Table 7 below is an example of an entropy decoding method for prediction mode information based on the size of the current block, under the assumptions described above (i.e., considered as inter-frame prediction without signaling to pred_mode_flag).

[0180] Table 7

[0181]

[0182] In Table 7, when the area of ​​the current block is less than the preset value (8192), the prediction mode information can be entropy decoded, while in the opposite case, the prediction mode information will not be entropy decoded.

[0183] That is, when the area of ​​the current block is greater than or equal to a preset value, the prediction mode of the current block can be implicitly determined as inter-frame prediction without entropy decoding of the prediction mode information.

[0184] As explained in Tables 4 to 7, when the size of the current block is greater than or equal to a preset value, the prediction mode information (pred_mode_flag) does not need to be encoded / decoded, and the prediction mode of the current block can be regarded as inter-frame prediction.

[0185] Under the premise described above (i.e., considering it as inter-frame prediction without signaling to pred_mode_flag), Figure 6 , Figure 7 as well as Figure 12 The conditions can also be changed. That is, in Figure 6 The code can be modified so that if at least one of the width or height of the current block is greater than or equal to a preset value (S601 - Yes), entropy encoding / decoding of the prediction mode information (pred_mode_flag) is not performed, but only if the opposite is true (S601 - No) is entropy encoding / decoding performed (S602). Similarly, in Figure 7 The code can be modified so that when the area of ​​the current block is greater than or equal to a preset value (S701 - Yes), entropy encoding / decoding of the prediction mode information (pred_mode_flag) is not performed, but only when the opposite condition is met (S701 - No) is entropy encoding / decoding performed (S702). Similarly, in... Figure 12 The algorithm can be modified to perform entropy encoding / decoding on the prediction mode information (pred_mode_flag) when the distance between the current image and the reference image is greater than or equal to a preset value (S1201-Yes), and only when the opposite is true (S1201-No), it does not perform entropy encoding / decoding on the prediction mode information (pred_mode_flag).

[0186] In addition, see Figures 4 to 16 The illustrated embodiments can be executed in the image encoding device 100 and the image decoding device 200.

[0187] However, the order in which the above embodiments are applied may be different in the image encoding device 100 and the image decoding device 200, and the order in which the above embodiments are applied may also be the same in the image encoding device 100 and the image decoding device 200.

[0188] Figure 15 This is a flowchart illustrating an image decoding method applicable to one embodiment of the present invention.

[0189] See Figure 15The image decoding device can determine the prediction mode of the current block based on at least one of the distance between the current image and the reference image and the size of the current block (S1501).

[0190] Next, the image decoding device can generate a prediction block for the current block based on the determined prediction mode (S1502).

[0191] The step of determining the prediction mode of the current block (S1501) can, if the size of the current block is greater than or equal to a preset value, not perform entropy decoding on the prediction mode information of the current block, and determine the prediction mode of the current block as the inter-frame prediction mode. Alternatively, if the size of the current block is less than a preset value, the prediction mode of the current block can be determined based on the prediction mode information of the current block.

[0192] Furthermore, in the step of determining the prediction mode of the current block (S1501), if the size of the current block is less than a preset value, entropy decoding of the prediction mode information of the current block can be omitted, and the prediction mode of the current block can be determined as the in-frame prediction mode. Alternatively, if the size of the current block is greater than or equal to the preset value, the prediction mode of the current block can be determined based on the prediction mode information of the current block.

[0193] The size of the current block can be at least one of the width, height, and area of ​​the current block.

[0194] Furthermore, in the step of determining the prediction mode of the current block (S1501), if the distance between the current image and the reference image is greater than or equal to a preset value, entropy decoding of the prediction mode information of the current block can be omitted, and the prediction mode of the current block can be determined as the in-frame prediction mode. Conversely, if the distance between the current image and the reference image is less than a preset value, the prediction mode of the current block can be determined based on the prediction mode information of the current block.

[0195] Furthermore, in the step of determining the prediction mode of the current block (S1501), if the distance between the current image and the reference image is less than a preset value, entropy decoding of the prediction mode information of the current block can be omitted, and the prediction mode of the current block can be determined as the inter-frame prediction mode. Alternatively, if the distance between the current image and the reference image is greater than or equal to a preset value, the prediction mode of the current block can be determined based on the prediction mode information of the current block.

[0196] The distance between the current image and the reference image can be the minimum difference between the image order count (POC) of the current image and the image order count (POC) of the reference image of the current block.

[0197] Figure 16 This is a flowchart illustrating an image decoding method applicable to one embodiment of the present invention.

[0198] See Figure 16 The image decoding device can perform entropy decoding on the prediction mode information of the current block based on at least one of the distance between the current image and the reference image and the size of the current block (S1601).

[0199] Next, the image decoding device can generate a prediction block for the current block based on the prediction mode information obtained from entropy decoding (S1602).

[0200] The step of entropy decoding of the prediction mode information of the current block (S1601) may include: increasing the initial context model probability of the prediction mode information of the current block when the size of the current block is less than a preset value; and entropy decoding of the prediction mode information of the current block using the initial context model.

[0201] Furthermore, the step of entropy decoding the prediction mode information of the current block (S1601) may include: determining the context model of the prediction mode information of the current block as a first context model when the size of the current block is greater than or equal to a preset value, and determining the context model of the prediction mode information of the current block as a second context model when the size of the current block is less than the preset value; and performing entropy decoding on the prediction mode information of the current block using the determined context model. The second context model may be a context model whose prediction mode information value has a higher probability of indicating the value of the prediction mode within the frame compared to the first context model.

[0202] Furthermore, the step of entropy decoding of the prediction mode information of the current block (S1601) may include: increasing the initial context model probability of the prediction mode information of the current block when the distance between the current image and the reference image is greater than or equal to a preset value; and entropy decoding of the prediction mode information of the current block using the initial context model.

[0203] Furthermore, the step of entropy decoding the prediction mode information of the current block (S1601) may include: determining the context model of the prediction mode information of the current block as a second context model when the distance between the current block and the reference image is greater than or equal to a preset value, and determining the context model of the prediction mode information of the current block as a first context model when the size of the current block is less than a preset value; and performing entropy decoding on the prediction mode information of the current block using the determined context model. The second context model may be a context model whose prediction mode information value has a higher probability of indicating the value of the prediction mode within the image compared to the first context model.

[0204] Figure 17 This is a flowchart illustrating an image encoding method applicable to one embodiment of the present invention.

[0205] See Figure 17 The image encoding apparatus can determine whether or not to entropy encode the prediction mode information of the current block based on at least one of the distance between the current image and the reference image and the size of the current block (S1701). The step of determining whether or not to encode the prediction mode information based on at least one of the distance between the current image and the reference image and the size of the current block has been described in [reference needed]. Figure 6 , Figure 7 as well as Figure 12 Detailed explanations have been provided, so repeated explanations will be omitted here.

[0206] Next, the image encoding device can generate a bitstream based on the above decision (S1702). Specifically, if it is decided not to perform entropy encoding on the prediction mode information of the current block, the image encoding device can generate a bitstream that does not contain the prediction mode information of the current block.

[0207] Figure 18 This is a flowchart illustrating an image encoding method applicable to one embodiment of the present invention.

[0208] See Figure 18 The image coding apparatus can perform entropy coding on the prediction mode information of the current block based on at least one of the distance between the current image and the reference image and the size of the current block (S1801). The step of performing entropy coding on the prediction mode information of the current block based on at least one of the distance between the current image and the reference image and the size of the current block has been described in [reference needed]. Figure 8 , Figure 9 , Figure 13 as well as Figure 14 Detailed explanations have been provided, so repeated explanations will be omitted here.

[0209] Next, the image encoding device can generate a bitstream containing prediction mode information encoded by entropy (S1802).

[0210] The exemplary methods in this disclosure are described as a sequence of actions for clarity of explanation, but this is not intended to limit the order in which the steps are executed. The steps may be executed simultaneously or in different orders if necessary. To implement the methods in this disclosure, additional steps may be added to the example steps, or only the remaining steps may be included, or additional steps may be added after excluding a portion of the steps.

[0211] The various embodiments described herein are not a list of all possible combinations, but are merely illustrative of representative forms of the disclosure. The matters described in the various embodiments may be applied independently or in combination of two or more.

[0212] Furthermore, the various embodiments described in this disclosure can be implemented using hardware, firmware, software, or a combination thereof. When implemented in hardware, they can be implemented using one or more application-specific integrated circuits (ACICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, and microprocessors.

[0213] The scope of this disclosure includes software or device-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that are executable on a device or computer and are applicable to actions in methods applicable to various embodiments, as well as a device or computer-executable non-transitory computer-readable medium storing the software or instructions as described above.

[0214] Industry availability

[0215] This invention can be used as an apparatus for encoding / decoding images.

Claims

1. An image decoding method, characterized in that, Includes the following steps: The prediction pattern for the current block is determined based on the size of the current block; and, Based on the prediction pattern determined above, a prediction block for the current block is generated; In the step of determining the prediction mode for the current block, the prediction mode for the current block is determined based on the comparison result between the size of the current block and a preset value. The size of the current block includes its width and height. Specifically, when the width and height of the current block are both equal to the preset values, the prediction mode of the current block is determined to be the in-screen prediction mode, and entropy decoding is not performed on the prediction mode information of the current block.

2. The image decoding method according to claim 1, characterized in that: In the steps of determining the prediction mode for the current block, When the size of the current block is greater than a preset value, the prediction mode information of the current block is entropy decoded, and the prediction mode of the current block is determined based on the prediction mode information of the current block obtained by the entropy decoding.

3. An image encoding method, characterized in that, Includes the following steps: The prediction pattern for the current block is determined based on the size of the current block; and, A bitstream is generated based on the above decision; In the step of determining the prediction mode of the current block, the determination of whether or not to entropy encode the prediction mode information is based on the comparison result between the size of the current block and a preset value. The size of the current block includes its width and height. Specifically, when the width and height of the current block are both equal to the preset values, the prediction mode of the current block is determined to be the in-screen prediction mode, and the prediction mode information of the current block is not entropy coding.

4. A computer-readable, non-transitory recording medium, characterized in that: In a computer-readable, non-transitory recording medium containing the bitstream used in image decoding, The aforementioned bitstream contains prediction mode information for the current block. In the aforementioned image decoding, the prediction mode for the current block is determined based on the comparison between the current block size and a preset value. The size of the current block includes its width and height. When the width and height of the current block are both equal to the preset values, the prediction mode information of the current block is not entropy decoded, and the prediction mode of the current block is determined to be the in-frame prediction mode.

Images