KR-102962344-B1 - METHOD AND APPARATUS FOR QUANTIZATION MATRIX ENCODING/DECODING AND RECORDING MEDIUM FOR STORING BITSTREAM

KR102962344B1KR 102962344 B1KR102962344 B1KR 102962344B1KR-102962344-B1

Abstract

In the present disclosure, a video decoding method is provided, comprising the steps of: determining one or more adaptive parameter sets including a set of quantization matrices composed of a plurality of quantization matrices; determining one or more adaptive parameter sets including a set of quantization matrices applied to a current picture or a current slice among the one or more adaptive parameter sets; de-quantizing the transform coefficients of a current block of a current picture or a current slice based on the set of quantization matrices of the determined adaptive parameter sets; and restoring the current block based on the de-quantized transform coefficients, wherein the adaptive parameter set includes encoding information applied to one or more pictures or slices.

Inventors

임성창
강정원
이하현
이진호
김휘용

Assignees

한국전자통신연구원

Dates

Publication Date: 20260508
Application Date: 20200615
Priority Date: 20190614

Claims (20)

A step of decoding one or more sets of adaptive parameters including a set of quantization matrices composed of multiple quantization matrices; Among the above one or more sets of adaptive parameters, a set of adaptive parameters including a set of quantization matrices applied to a current picture or a current slice is determined, wherein the current picture or the current slice includes a current block; A step of determining the quantization matrix of the current block based on the set of quantization matrices of the above-mentioned adaptive parameter set; A step of inversely quantizing the transformation coefficients of the current block based on the quantization matrix; and Based on inversely quantized transformation coefficients, the method includes the step of obtaining residual samples of the current block, and The quantization matrix of the current block is selected from the set of quantization matrices of the set of adaptation parameters based on at least one of the prediction mode, color component, and magnitude of the current block, and A video decoding method characterized in that the quantization matrix of the current block is selected identically when the prediction mode of the current block is an in-frame block copy mode and when the prediction mode of the current block is an inter-frame prediction mode.
In paragraph 1, The above adaptive parameter set includes an adaptive parameter set identifier indicating an identifier of the above adaptive parameter set, and The set of adaptation parameters for the current picture or the current slice is determined based on a quantization matrix set identifier obtained from the bitstream, and A video decoding method characterized in that the adaptive parameter set for the current picture or the current slice has an adaptive parameter set identifier having a value corresponding to the quantization matrix set identifier.
In paragraph 2, A video decoding method characterized in that the quantization matrix set identifier is obtained from the bitstream when the quantization matrix allow flag obtained from the bitstream indicates that the current picture or the current slice can use the quantization matrix set of the one or more adaptation parameter sets.
delete
In paragraph 1, The above set of adaptation parameters is, It includes adaptive parameter set type information indicating one of the encoding information types included in the above adaptive parameter set, and A video decoding method in which the adaptive parameter set for the current picture or the current slice is such that the adaptive parameter set type information indicates a quantization matrix type.
In paragraph 5, The above encoding information types are, A video decoding method characterized by including one of the above-mentioned quantization matrix type, adaptive loop filter type, or chrominance scaling and luminance mapping type.
In paragraph 1, Secondary transformation quantization matrix allowance information indicating whether it is allowed to apply a set of quantization matrices of one or more adaptation parameter sets to a block to which a secondary transformation is applied is obtained from a bitstream, and A video decoding method characterized in that, when the second transformation quantization matrix allowance information indicates that the quantization matrix set of the adaptation parameter set determined for the block to which the second transformation is applied is not applied, and the second transformation usage information for the current block indicates that the current block has undergone a second transformation, the inverse quantization of the transformation coefficients is performed based on the basic quantization matrix.
In Paragraph 7, The above fundamental quantization matrix is, A video decoding method characterized by being composed of quantization coefficients of the same value within a quantization matrix.
delete
delete
In paragraph 1, The above set of quantization matrices is, A video decoding method characterized by including first quantization matrices used for a block with a maximum height and width of 2, second quantization matrices used for a block with a maximum height and width of 4, third quantization matrices used for a block with a maximum height and width of 8, fourth quantization matrices used for a block with a maximum height and width of 16, fifth quantization matrices used for a block with a maximum height and width of 32, and sixth quantization matrices used for a block with a maximum height and width of 64.
In Paragraph 11, The first quantization matrices used in blocks where the maximum values of the height and width are 2 are, A video decoding method characterized by including only a quantization matrix used for a block regarding a Cr component while inter-frame prediction or intra-frame block copy prediction, and a quantization matrix used for a block regarding a Cb component while inter-frame prediction or intra-frame block copy prediction.
In paragraph 1, The decoding of the current quantization matrix within the set of quantization matrices of the above one or more adaptation parameter sets is, A video decoding method characterized by being performed based on a restoration method of one of a quantization matrix copy mode, a prediction mode between quantization matrices, and a DPCM mode within the quantization matrix.
In Paragraph 13, The determination of the above restoration method of the above current quantization matrix is, If a quantization matrix copy mode flag obtained from a bitstream indicates that the quantization matrix copy mode is applied to the current quantization matrix, the restoration method of the current quantization matrix is determined to be the quantization matrix copy mode, and If the above quantization matrix copy mode flag indicates that the above quantization matrix copy mode is not applied, an additional prediction mode flag between quantization matrices is obtained from the bitstream, and If the prediction mode flag between the quantization matrices indicates that the prediction mode between the quantization matrices is applied to the current quantization matrix, the restoration method of the current quantization matrix is determined as the prediction mode between the quantization matrices, and A video decoding method characterized in that when the prediction mode flag between the quantization matrices indicates that the prediction mode between the quantization matrices is not applied, the restoration method of the current quantization matrix is determined as a DPCM mode within the quantization matrix.
In Paragraph 13, A video decoding method characterized in that, when the method for restoring the current quantization matrix is in the quantization matrix copy mode, a quantization matrix decoded earlier than the current quantization matrix is set as a reference quantization matrix, and the current quantization matrix is restored to be identical to the reference quantization matrix.
In paragraph 15, When the maximum values of the height and width of the current block are 2, the previously decoded quantization matrix with maximum values of height and width of 2 is determined as the reference quantization matrix, and When the maximum values of the height and width of the current block are 4, the previously decoded quantization matrix with maximum values of height and width of 4 is determined as the reference quantization matrix, and When the maximum values of the height and width of the current block are 8, the previously decoded quantization matrix with maximum values of height and width of 8 is determined as the reference quantization matrix, and When the maximum height and width of the current block is 16, a previously decoded quantization matrix with a maximum height and width of 8 is determined as the reference quantization matrix, and When the maximum height and width of the current block are 32, a previously decoded quantization matrix with a maximum height and width of 8 is determined as the reference quantization matrix, and A video decoding method characterized in that when the maximum values of the height and width of the current block are 64, a previously decoded quantization matrix having maximum values of the height and width of 8 is determined as the reference quantization matrix.
In Paragraph 13, If the above recovery method of the above current quantization matrix is a prediction mode between the above quantization matrices, the quantization matrix decoded earlier than the above current quantization matrix is set as the reference quantization matrix, and After obtaining the difference quantization matrix coefficients representing the difference between the matrix coefficients of the current quantization matrix and the matrix coefficients of the reference quantization matrix, A video decoding method characterized by determining the matrix coefficients of the current quantization matrix according to the sum of the matrix coefficients of the reference quantization matrix and the differential quantization matrix coefficients.
In Paragraph 17, When the maximum values of the height and width of the current block are 2, the previously decoded quantization matrix with maximum values of height and width of 2 is determined as the reference quantization matrix, and When the maximum values of the height and width of the current block are 4, the previously decoded quantization matrix with maximum values of height and width of 4 is determined as the reference quantization matrix, and When the maximum values of the height and width of the current block are 8, the previously decoded quantization matrix with maximum values of height and width of 8 is determined as the reference quantization matrix, and When the maximum height and width of the current block is 16, a previously decoded quantization matrix with a maximum height and width of 8 is determined as the reference quantization matrix, and When the maximum height and width of the current block are 32, a previously decoded quantization matrix with a maximum height and width of 8 is determined as the reference quantization matrix, and A video decoding method characterized in that when the maximum values of the height and width of the current block are 64, a previously decoded quantization matrix having maximum values of the height and width of 8 is determined as the reference quantization matrix.
A step of determining one or more sets of adaptive parameters including a set of quantization matrices composed of multiple quantization matrices; Among the above one or more sets of adaptive parameters, a set of adaptive parameters including a set of quantization matrices applied to a current picture or a current slice is determined, wherein the current picture or the current slice includes a current block; A step of determining the quantization matrix of the current block based on the set of quantization matrices of the determined set of adaptive parameters; A step of quantizing the transformation coefficients of the current block based on the quantization matrix; and The quantization matrix of the current block is selected from the set of quantization matrices of the set of adaptation parameters based on at least one of the prediction mode, color component, and magnitude of the current block, and A video encoding method characterized in that the quantization matrix of the current block is selected identically when the prediction mode of the current block is an intra-frame block copy mode and when the prediction mode of the current block is an inter-frame prediction mode.
In a computer-readable recording medium storing a bitstream generated by encoding video by a video encoding method, The above video encoding method is, A step of determining one or more sets of adaptive parameters including a set of quantization matrices composed of multiple quantization matrices; Among the above one or more sets of adaptive parameters, a set of adaptive parameters including a set of quantization matrices applied to a current picture or a current slice is determined, wherein the current picture or the current slice includes a current block; A step of determining the quantization matrix of the current block based on the set of quantization matrices of the determined set of adaptive parameters; A step of quantizing the transformation coefficients of the current block based on the quantization matrix; and The quantization matrix of the current block is selected from the set of quantization matrices of the set of adaptation parameters based on at least one of the prediction mode, color component, and magnitude of the current block, and A computer-readable recording medium characterized in that the quantization matrix of the current block is selected identically when the prediction mode of the current block is an in-frame block copy mode and when the prediction mode of the current block is an inter-frame prediction mode.

Description

Method and apparatus for quantization matrix encoding/decoding and recording medium for storing bitstream The present invention relates to a method and apparatus for encoding/decoding an image, and more specifically, to a method and apparatus for encoding/decoding an image based on a quantization matrix. Recently, the demand for high-resolution, high-quality video, such as HD (High Definition) and UHD (Ultra High Definition) video, has been increasing across various application fields. As video data becomes higher in resolution and quality, the relative volume of data increases compared to conventional video data; consequently, transmission and storage costs increase when video data is transmitted using existing wired or wireless broadband lines or stored using existing storage media. To address these issues arising from the increase in video data resolution and quality, high-efficiency video encoding and decoding technologies for video with higher resolution and quality are required. Various video compression technologies exist, such as inter-frame prediction technology that predicts pixel values in the current picture from previous or subsequent pictures, intra-frame prediction technology that predicts pixel values in the current picture using pixel information within the current picture, transformation and quantization technology for compressing the energy of residual signals, and entropy coding technology that assigns short codes to values with high frequency and long codes to values with low frequency; by utilizing these video compression technologies, video data can be effectively compressed for transmission or storage. Conventional quantization matrix encoding/decoding only considers the prediction mode, color components, and magnitude, so there are limitations in the objective and subjective image quality. FIG. 1 is a block diagram showing the configuration according to one embodiment of an encoding device to which the present invention is applied. FIG. 2 is a block diagram showing the configuration according to one embodiment of a decoding device to which the present invention is applied. Figure 3 is a diagram schematically showing the segmentation structure of an image when encoding and decoding an image. Figure 4 is a diagram illustrating an example of an in-screen prediction process. Figure 5 is a diagram illustrating an example of an inter-frame prediction process. Figure 6 is a diagram illustrating the process of transformation and quantization. Figure 7 is a diagram illustrating reference samples available for in-screen prediction. FIG. 8a is a diagram illustrating the operation method of a device for encoding a quantization matrix according to an embodiment of the present invention. And FIG. 8b is a diagram for explaining the operation method of a device for decoding a quantization matrix according to one embodiment of the present invention. FIGS. 9 to 17 illustrate an embodiment of a method for constructing a quantization matrix based on at least one of a prediction mode, a color component, and a magnitude. FIGS. 18 to 20 are drawings illustrating syntax elements that signal information on whether a quantization matrix is used in a parameter set or header according to an embodiment of the present invention. FIGS. 21 to 26 are drawings for explaining the fundamental matrices used in the quantization/inverse quantization process according to one embodiment of the present invention. FIGS. 27 to 59 are diagrams illustrating the process of entropy encoding/decoding information of a quantization matrix prediction method according to an embodiment of the present invention. FIGS. 60 to 61 are drawings illustrating a process of performing prediction between quantization matrices according to the size of the quantization matrix according to an embodiment of the present invention. FIGS. 62 to 64 are drawings for illustrating a mapping table refMap according to an embodiment of the present invention. FIGS. 65 to 73 are drawings for illustrating a scanning method for quantization matrix coefficients according to an embodiment of the present invention. FIGS. 74 to 76 are drawings for explaining the process of restoring a quantization matrix according to an embodiment of the present invention. FIGS. 77 to 88 are drawings for explaining syntax element information, semantics of syntax element information, and encoding/decoding process required to implement a quantization matrix encoding/decoding method, apparatus, and a recording medium storing a bitstream in an encoder/decoder according to an embodiment of the present invention. FIGS. 89 to 100 are drawings for explaining the fundamental matrix used in the quantization/inverse quantization process according to one embodiment of the present invention. FIGS. 101 to 110 illustrate syntax element information, semantics of syntax element information, and examples of encoding/decoding processes required to implement a quantization matrix encoding/decoding method