Patents by Inventor Moonmo Koo
Moonmo Koo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11979609Abstract: The present disclosure, in a method of decoding a video signal, provides a method including checking whether a transform skip is applied to a current block; acquiring a transform index indicating transform types applied to a horizontal direction and a vertical direction of the current block from among a plurality of predefined transform types from the video signal when the transform skip is not applied to the current block; and performing an inverse primary transform on the current block using the transform types indicated by the transform index, wherein the transform types applied to the horizontal direction and the vertical direction of the current block are determined from among transform types defined according to an intra prediction mode of the current block based on the transform index.Type: GrantFiled: April 12, 2023Date of Patent: May 7, 2024Assignee: LG ELECTRONICS INC.Inventors: Seunghwan Kim, Medhi Salehifar, Moonmo Koo, Jaehyun Lim
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Publication number: 20240146976Abstract: The present disclosure provides a method for decoding a video signal, the method comprising the steps of: decoding, from a bitstream, a syntax element indicating the last non-zero region, wherein the last non-zero region represents a region including the last non-zero transform coefficient in a scan order; splitting a current block into multiple sub-regions; and based on the syntax element, determining the last non-zero region of the current block among the split sub-regions.Type: ApplicationFiled: January 5, 2024Publication date: May 2, 2024Inventors: Moonmo KOO, Seunghwan KIM
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Publication number: 20240146966Abstract: According to the disclosure of the present disclosure: an LFNST set index for a current block may be derived on the basis of an intra prediction mode on the basis of the intra prediction mode for the current block being a WAIP mode, the LFNST set index may be derived as predetermined one value; and on the basis of the intra prediction mode for the current block being an NAIP mode, the LFNST set index may be derived as one of predetermined N values. Accordingly, it is possible to maximize the coding performance that can be brought about by LFNST within the implementation complexity allowed by a next standard.Type: ApplicationFiled: April 12, 2022Publication date: May 2, 2024Inventors: Moonmo KOO, Jaehyun LIM, Seunghwan KIM, Jie ZHAO
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Publication number: 20240146965Abstract: An image decoding method performed by means of a decoding device according to the present invention comprises the steps of: deriving quantized transform coefficients with respect to a target block from a bitstream; performing inverse quantization with respect to the quantized transform coefficients with respect to the target block and deriving transform coefficients; deriving residual samples with respect to the target block on the basis of reduced inverse transform with respect to the transform coefficients; and generating a reconstructed picture on the basis of the residual samples with respect to the target block and prediction samples with respect to the target block. The reduced inverse transform is performed on the basis of a reduced inverse transform matrix. The reduced inverse transform matrix is a non-square matrix of which the number of columns is smaller than the number of rows.Type: ApplicationFiled: December 19, 2023Publication date: May 2, 2024Inventors: Mehdi SALEHIFAR, Seunghwan KIM, Moonmo KOO, Jaehyun LIM
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Patent number: 11973951Abstract: An image decoding method according to the present document can comprise the steps of: acquiring, from a bitstream, intra prediction mode information and an LFNST index; deriving, as a cross-component linear model (CCLM) mode, an intra prediction mode of a chroma block on the basis of the intra prediction mode information; changing the intra prediction mode of the chroma block from the CCLM mode to an intra prediction mode of a luma block corresponding to the chroma block; determining an LFNST set, including LFNST matrices, on the basis of the intra prediction mode of the luma block; selecting one of the LFNST matrices on the basis of the LFNST set and the LFNST index; and deriving transform coefficients for the chroma block on the basis of the selected LFNST matrix.Type: GrantFiled: January 10, 2022Date of Patent: April 30, 2024Assignee: LG ELECTRONICS INC.Inventors: Moonmo Koo, Seunghwan Kim, Jaehyun Lim
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Patent number: 11973963Abstract: An image decoding method according to the present disclosure includes deriving transform coefficients through dequantization based on the quantized transform coefficients for the target block; deriving modified transform coefficients based on an inverse reduced secondary transform (RST) for the transform coefficients; deriving residual samples for the target block based on an inverse primary transform for the modified transform coefficients; and generating a reconstructed samples based on the residual samples, and prediction samples derived based on an intra prediction mode for the target block, wherein the inverse RST is performed based on a transform kernel matrix selected from a transform set including a plurality of transform kernel matrices, the transform set is determined based on a mapping relationship according to the intra prediction mode applied to the target block, and a plurality of intra prediction modes including the intra prediction mode of the target block are mapped to one transform set.Type: GrantFiled: December 27, 2022Date of Patent: April 30, 2024Assignee: LG ELECTRONICS INC.Inventors: Moonmo Koo, Mehdi Salehifar, Seunghwan Kim, Jaehyun Lim
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Publication number: 20240137512Abstract: An image decoding method according to the present document comprises a step for performing inverse first-order transform and inverse non-separable transform on a residual sample. The inverse non-separable transform is performed on the basis of a transform index indicating a predetermined transform kernel matrix, the inverse first-order transform is performed on the basis of a multiple transform selection (MTS) index indicating MTS for a horizontal transform kernel and a vertical transform kernel, and a syntax element bin string for the transform index is derived on the basis of first context information when a tree type for a split structure of a target block is not a single tree type and is derived on the basis of second context information when the tree type is the single tree type.Type: ApplicationFiled: December 5, 2023Publication date: April 25, 2024Inventors: Moonmo KOO, Jaehyun LIM, Junghak NAM, Seunghwan kim
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Patent number: 11968398Abstract: The present disclosure provides a method of reconstructing a video signal based on a reduced secondary transform, which includes: obtaining a secondary transform index from the video signal; deriving a secondary transform corresponding to the secondary transform index, wherein the secondary transform represents a reduced secondary transform, and the reduced secondary transform represents a transform outputting L (L<N) transform coefficient data (L×1 transform coefficient vectors) based on inputted N residual data (N×1 residual vectors); obtaining a transform coefficient block by performing an entropy decoding and a dequantization for a current block (N×N); performing an inverse secondary transform for the transform coefficient block using the reduced secondary transform; performing an inverse primary transform for a block which the inverse secondary transform is applied to; and reconstructing the current block using a block which the inverse primary transform is applied to.Type: GrantFiled: February 14, 2023Date of Patent: April 23, 2024Assignee: LG Electronics Inc.Inventors: Moonmo Koo, Mehdi Salehifar, Seunghwan Kim, Jaehyun Lim
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Patent number: 11968397Abstract: A video decoding method according to the present document is characterized by comprising: a step for deriving transform coefficients through inverse quantization on the basis of quantized transform coefficients for a target block; a step for deriving modified transform coefficients on the basis of an inverse reduced secondary transform (RST) of the transform coefficients; and a step for generating a reconstructed picture on the basis of residual samples for the target block on the basis of an inverse primary transform of the modified transform coefficients, wherein the inverse RST using a transform kernel matrix is performed on transform coefficients of the upper-left 4×4 region of an 8×8 region of the target block, and the modified transform coefficients of the upper-left 4×4 region, upper-right 4×4 region, and lower-left 4×4 region of the 8×8 region are derived through the inverse RST.Type: GrantFiled: January 19, 2023Date of Patent: April 23, 2024Assignee: LG Electronics Inc.Inventors: Moonmo Koo, Seunghwan Kim, Jaehyun Lim
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Publication number: 20240129467Abstract: The present disclosure provides a method for reconstructing a video signal, which includes: obtaining a transform coefficient block by performing an entropy decoding and a dequantization for a current block; deriving a secondary transform corresponding to a specific area in the transform coefficient block, wherein the specific area represents an area including a top-left block of the transform coefficient block; performing an inverse secondary transform for each of subblocks within the specific area using the secondary transform; performing an inverse primary transform for a block which the inverse secondary transform is applied to; and reconstructing the current block using a block which the primary inverse transform is applied to.Type: ApplicationFiled: December 18, 2023Publication date: April 18, 2024Inventors: Moonmo KOO, Mehdi SALEHIFAR, Seunghwan KIM, Jaehyun LIM
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Publication number: 20240129476Abstract: An image decoding method, according to the present document, may comprise the steps of: deriving transform coefficients for a current block on the basis of residual information; determining whether a significant coefficient is present in a second region excluding a first region in the top-left end of the current block; parsing a LFNST index from a bitstream if the significant coefficient is not present in the second region; deriving modified transform coefficients by applying a LFNST matrix, derived on the basis of the LFNST index, to transform coefficients of the first region; and deriving residual samples of the current block on the basis of an inverse primary transform of the modified transform coefficients.Type: ApplicationFiled: December 7, 2023Publication date: April 18, 2024Inventors: Moonmo KOO, Jaehyun LIM, Junghak NAM, Seunghwan KIM
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Patent number: 11962779Abstract: An image decoding method according to the present document comprises the steps of: deriving flag information indicating whether valid coefficients are present in a second area excluding a first area of the upper left corner of the current block; parsing an MTS index from a bitstream on the basis of the flag information indicating the absence of valid coefficients in the second area; and deriving residual samples for the current block by applying a conversion kernel derived on the basis of the MTS index to conversion coefficients of the first area, wherein the flag information may be derived by determining, for each scan sub-block in which the valid coefficients are scanned, whether the valid coefficients are present in the second area.Type: GrantFiled: November 9, 2020Date of Patent: April 16, 2024Assignee: LG Electronics Inc.Inventors: Moonmo Koo, Seunghwan Kim, Mehdi Salehifar, Jaehyun Lim
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Publication number: 20240121394Abstract: An image decoding method according to the present document may be characterized by including the steps of: determining whether to parse an MTS index for applying MTS to the current block; and applying the MTS to the current block on the basis of the MTS index to derive residual samples for the current block, wherein whether to parse the MTS index is determined on the basis of a flag value indicating whether a transform coefficient for a luma component of the current block is present, and the MTS index is not parsed when the flag value is 0.Type: ApplicationFiled: October 8, 2020Publication date: April 11, 2024Inventors: Moonmo KOO, Jaehyun LIM, Seunghwan KIM, Mehdi SALEHIFAR
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Publication number: 20240114166Abstract: Embodiments of the present disclosure provide a method and device for processing a video signal. A method for decoding an image signal according to an embodiment of the present disclosure comprises the steps of: determining a non-separable transform set index indicating a non-separable transform set used for a non-separable transform of a current block from among non-separable transform sets predefined on the basis of an intra-prediction mode of the current block; determining. as a non-separable transform matrix, a transform kernel indicated by a non-separable transform index for the current block from among transform kernels included in the non-separable transform set indicated by the non-separable transform set index; and applying the non-separable transform matrix to an upper left region which of the current block, which is determined according to the width and height of the current block, wherein each of the predefined non-separable transform sets includes two transform kernels.Type: ApplicationFiled: November 27, 2023Publication date: April 4, 2024Inventors: Moonmo KOO, Mehdi Salehifar, Seunghwan Kim, Jaehyun Lim
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Publication number: 20240114159Abstract: The present invention relates to a video signal decoding method based on a Multiple Transform Selection (MTS).Type: ApplicationFiled: November 1, 2023Publication date: April 4, 2024Inventors: Moonmo Koo, Mehdi Salehifar, Seunghwan Kim, Jaehyun Lim
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Patent number: 11949873Abstract: An image decoding method according to the present document comprises a step of applying an inverse primary transform to a transform coefficient so as to derive residual samples for a current block, wherein: the inverse primary transform is performed on the basis of an MTS index received from a bitstream; the MTS index is parsed on the basis of an effective coefficient not existing in a second area that excludes the left top first area of the current block; and the first area is a left top 16×16 area of the current block.Type: GrantFiled: November 9, 2020Date of Patent: April 2, 2024Assignee: LG Electronics Inc.Inventors: Moonmo Koo, Seunghwan Kim, Mehdi Salehifar, Jaehyun Lim
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Patent number: 11943474Abstract: Embodiments in the present specification provide a video signal processing method and device. A method of processing a video signal according to an embodiment in the present specification comprises the steps of: acquiring an intra-prediction mode for a current block from the video signal; determining a modified intra-prediction mode from the intra-prediction mode for the current block on the basis of the width and height of and the intra-prediction mode for the current block; and applying a transform determined on the basis of the modified intra-prediction mode. The accuracy of prediction can be further improved by deriving a modified intra-prediction mode according to a wide-angle intra-prediction mode according to the shape of and an intra-prediction mode for a current block.Type: GrantFiled: December 1, 2022Date of Patent: March 26, 2024Assignee: LG ELECTRONICS INC.Inventors: Moonmo Koo, Jaehyun Lim, Seunghwan Kim
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Patent number: 11943479Abstract: A method for processing a video signal includes determining a horizontal transform type index for a horizontal transform kernel and a vertical transform type index for a vertical transform kernel of a transform block in the video signal, determining a transform region in which a significant transform coefficient exists in the transform block based on the horizontal transform type index, the vertical transform type index, and a size of the transform block, and applying inverse-transform to the transform region based on the horizontal transform type index and the vertical transform type index. A width of the transform region is determined based on a comparison between the horizontal transform type index and a reference value, and a height of the transform region is determined based on a comparison between the vertical transform type index and the reference value.Type: GrantFiled: January 2, 2020Date of Patent: March 26, 2024Assignee: LG ELECTRONICS INC.Inventors: Moonmo Koo, Jaehyun Lim, Seunghwan Kim
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Patent number: 11943445Abstract: An image decoding method according to the present document may comprise the steps of: receiving image information including residual information and an LFNST index from a bitstream; deriving a transform coefficient on the basis of the residual information; deriving a flag variable related to whether LFNST is applied to a current block on the basis of the LFNST index; and performing the LFNST on the basis of the flag variable and the transform coefficient, wherein the flag variable is derived for each color component of the current block.Type: GrantFiled: November 11, 2022Date of Patent: March 26, 2024Assignee: LG Electronics Inc.Inventors: Moonmo Koo, Jie Zhao, Hyeongmoon Jang, Seunghwan Kim, Jaehyun Lim
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Patent number: 11943456Abstract: An image decoding method according to the present document comprises the steps of: deriving a transform coefficient for a current block on the basis of residual information; deriving a residual sample by applying, to the transform coefficient, at least one of LFNST and MTS; and generating a reconstructed picture on the basis of the residual samples, wherein the LFNST is performed on the basis of an LFNST index indicating an LFNST kernel, the MTS is performed on the basis of an MTS index indicating an MTS kernel, and the LFNST index may be parsed before the MTS index.Type: GrantFiled: July 11, 2022Date of Patent: March 26, 2024Assignee: LG ELECTRONICS INC.Inventors: Moonmo Koo, Jaehyun Lim, Seunghwan Kim