# US 2019/0174129 A1 · Image processing device and method for improving coding efficiency of quantization matrices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174129 A1 - Document ID: US20190174129A1 - Status: Published application - Kind: A1 - Application number: 16/258,685 - Filed: 2019-01-28 - Published: 2019-06-06 - Earliest claimed: 2012-02-29 - Assignees: Sony Corporation - Applicants: Sony Corporation - Inventors: Junichi TANAKA; Yoshitaka MORIGAMI - Web page: https://patentgrep.com/patent/US20190174129A1 ## CPC - H04N 19/124: Quantisation - H04N 19/122: Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type - H04N 19/126: Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers - H04N 19/18: the unit being a set of transform coefficients - H04N 19/30: using hierarchical techniques, e.g. scalability (H04N19/63 takes precedence) - H04N 19/463: by compressing encoding parameters before transmission - H04N 19/59: involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution - H04N 19/61: in combination with predictive coding - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image processing device and method that enable suppression of a reduction in coding efficiency. The image processing device dequantizes quantized data generated through decoding, using a default quantization matrix having a same size as a block size that is a unit of processing in which dequantization is performed, when in a copy mode in which a quantization matrix is copied, quantization matrix reference data identifying a reference destination of the quantization matrix matches quantization matrix identification data identifying the quantization matrix. The device and method can be applied to an image processing device. ## Claims ### Claim 1 An image processing device, comprising: circuitry configured to decode encoded data including a replacement difference coefficient, which is a difference between a replacement coefficient used to replace a (0, 0) coefficient of a 32×32 quantization matrix and a (0, 0) coefficient of an 8×8 quantization matrix to generate quantized data; set, a 32×32 default quantization matrix as the current quantization matrix, when a current quantization matrix is copied and as a condition that difference value between a value of identification information identifying a reference quantization matrix and a value of identification information identifying the current quantization matrix is equal to 0; set the 32×32 quantization matrix as the current quantization matrix by using a nearest neighboring interpolation process against the 8×8 quantization matrix including the sum of the replacement difference coefficient and the replacement coefficient as the (0, 0) coefficient of the 8×8 quantization matrix and by replacing the (0, 0) coefficient with the replacement coefficient, when the current quantization matrix is not copied; and dequantize the quantized data using the current quantization matrix, thereby improving coding efficiency. ### Claim 2 (depends on 1) The image processing device according to claim 1, wherein the circuitry is configured to: decode the encoded data including a difference coefficient, which is a difference between each coefficient of the 8×8 quantization matrix; and set, when the current quantization matrix is not copied, the 8×8 quantization matrix by adding the difference coefficient. ### Claim 3 (depends on 2) The image processing device according to claim 2, wherein the circuitry is configured to: decode the encoded data whose syntax is a group of difference coefficients. ### Claim 4 (depends on 3) The image processing device according to claim 3, wherein the circuitry is configured to: decode the replacement difference coefficient, and then decode the difference coefficient. ### Claim 5 (depends on 4) The image processing device according to claim 4, wherein the circuitry is configured to: decode the encoded data including an initial difference coefficient, which is a difference between the replacement coefficient and an initial value of a coefficient set to a quantization matrix; and set, when the current quantization matrix is not copied, the replacement coefficient by adding the initial difference coefficient into the initial value. ### Claim 6 (depends on 5) The image processing device according to claim 5, wherein the circuitry is configured to: decode the encoded data whose syntax is the initial difference coefficient and the group of difference coefficients. ### Claim 7 (depends on 6) The image processing device according to claim 6, wherein the circuitry is configured to: decode the initial difference coefficient, and then decode the group of difference coefficients. ### Claim 8 (depends on 7) The image processing device according to claim 7, wherein the circuitry is configured to: decode the encoded data whose syntax is the encoded initial difference coefficient and the encoded group of difference coefficients using signed exponential Golomb coding. ### Claim 9 (depends on 8) The image processing device according to claim 8, wherein the circuitry is configured to: decode the initial difference coefficient using signed exponential Golomb coding, and then decode the group of difference coefficients using signed exponential Golomb coding. ### Claim 10 (depends on 9) The image processing device according to claim 9, wherein the circuitry is configured to: dequantize the quantized data to generate transform coefficient data; and inversely transform the transform coefficient data. ### Claim 11 (depends on 10) The image processing device according to claim 10, wherein the circuitry is configured to: dequantize the quantized data using the 32×32 quantization matrix to generate the transform coefficient data; and inversely transform the transform coefficient data using a transformation unit of 32×32. ### Claim 12 An image processing method comprising: decoding encoded data that includes a replacement difference coefficient which is a difference between a replacement coefficient used to replace a (0, 0) coefficient of a 32×32 quantization matrix and a (0, 0) coefficient of an 8×8 quantization matrix, to generate quantized data; setting a 32×32 default quantization matrix as the current quantization matrix, when a current quantization matrix is copied and as a condition that a difference value between a value of identification information identifying a reference quantization matrix and a value of identification information identifying the current quantization matrix is equal to 0; setting the 32×32 quantization matrix as the current quantization matrix by using a nearest neighboring interpolation process against the 8×8 quantization matrix including the sum of the replacement difference coefficient and the replacement coefficient as the (0, 0) coefficient of the 8×8 quantization matrix and by replacing the (0, 0) coefficient with the replacement coefficient, when the current quantization matrix is not copied; and dequantizing the quantized data generated in the decoding, using the current quantization matrix, thereby improving coding efficiency. ### Claim 13 (depends on 12) The image processing method according to claim 12, wherein the decoding decodes the encoded data including a difference coefficient, which is a difference between each coefficient of the 8×8 quantization matrix; and the setting sets, when the current quantization matrix is not copied, the 8×8 quantization matrix by adding the difference coefficient. ### Claim 14 (depends on 13) The image processing method according to claim 13, wherein the decoding decodes the encoded data whose syntax is a group of difference coefficients. ### Claim 15 (depends on 14) The image processing method according to claim 14, wherein the decoding decodes the replacement difference coefficient, and then decodes the difference coefficient. ### Claim 16 (depends on 15) The image processing method according to claim 15, wherein the decoding decodes the encoded data including an initial difference coefficient, which is a difference between the replacement coefficient and an initial value of a coefficient set to a quantization matrix; and the setting sets, when the current quantization matrix is not copied, the replacement coefficient by adding the initial difference coefficient into the initial value. ### Claim 17 (depends on 16) The image processing method according to claim 16, wherein the decoding decodes the encoded data whose syntax is the initial difference coefficient and the group of difference coefficients. ### Claim 18 (depends on 17) The image processing method according to claim 17, wherein the decoding decodes the initial difference coefficient, and then decodes the group of difference coefficients. ### Claim 19 (depends on 18) The image processing method according to claim 18, wherein the decoding decodes the encoded data whose syntax is the encoded initial difference coefficient and the encoded group of difference coefficients using signed exponential Golomb coding. ### Claim 20 (depends on 19) The image processing method according to claim 19, wherein the decoding decodes the initial difference coefficient using signed exponential Golomb coding, and then decodes the group of difference coefficients using signed exponential Golomb coding. ### Claim 21 (depends on 20) The image processing method according to claim 20, wherein the dequantizing dequantizes the quantized data to generate transform coefficient data; and the method further comprises inversely transforming the transform coefficient data. ### Claim 22 (depends on 21) The image processing method according to claim 21, wherein the dequantizing dequantizes the quantized data using the 32×32 quantization matrix to generate the transform coefficient data; and the inversely transforming inversely transforms the transform coefficient data using a transformation unit of 32×32.