Abstract: Techniques are described for express and implied signaling of transform mode selections in video coding. Information derived from coefficient samples in a given transform unit (TU) or prediction unit (PU) may constrain or modify signaling of certain syntax elements at the coding block (CB), TU, or PU levels. For instance, based on the spatial locations of decoded coefficients, the spatial patterns of coefficients, or the correlation with the coefficients in neighboring blocks, various syntax elements such as the transform type and related flags/indices or secondary transform modes/flags indices, a residual coding mode, intra and inter prediction modes, and scanning order may be disabled or constrained. In another case, if the coefficient samples match a desired spatial pattern or have other desired properties then a default transform type, a default secondary transform type, a default intra and inter prediction mode or other block level modes may be inferred at the decoder side.

Abstract: The present invention provides a method for encoding a video signal based on an Edge Adaptive Graph-Based Transform (EA-GBT) including detecting a step edge or a ramp edge from a residual signal; generating a graph signal based on at least one of the step edge or the ramp edge; obtaining an EA-GBT coefficient by performing the EA-GBT for the graph signal; quantizing the EA-GBT coefficient; and entropy-encoding the quantized EA-GBT coefficient.

Abstract: The present invention provides a method for encoding a video signal on the basis of a graph-based separable transform (GBST), the method comprising the steps of: generating an incidence matrix representing a line graph; training a sample covariance matrix for rows and columns from the rows and columns of a residual signal; calculating a graph Laplacian matrix for rows and columns on the basis of the incidence matrix and the sample covariance matrix for rows and columns; and obtaining a GBST by performing eigen decomposition of the graph Laplacian matrix for rows and columns.

Abstract: The present invention, with respect to a method of processing video data, provides a method of processing video data, provides a method characterized by comprising the steps of: performing a clustering for the video data; generating at least one data cluster as a result of the clustering; generating at least one Graph laplacian matrix corresponding to the at least one data cluster; performing conversion optimization on the basis of multiple graph-based models, wherein the multiple graph-based models respectively include at least one graph laplacian matrix; and generating an optimized conversion matrix according to the results of performing the conversion optimization.

Abstract: The present invention provides a method for encoding a video signal on the basis of a graph-based separable transform (GBST), the method comprising the steps of: generating an incidence matrix representing a line graph; training a sample covariance matrix for rows and columns from the rows and columns of a residual signal; calculating a graph Laplacian matrix for rows and columns on the basis of the incidence matrix and the sample covariance matrix for rows and columns; and obtaining a GBST by performing eigen decomposition of the graph Laplacian matrix for rows and columns.

Abstract: The present invention provides a method for encoding a video signal based on an Edge Adaptive Graph-Based Transform (EA-GBT) including detecting a step edge or a ramp edge from a residual signal; generating a graph signal based on at least one of the step edge or the ramp edge; obtaining an EA-GBT coefficient by performing the EA-GBT for the graph signal; quantizing the EA-GBT coefficient; and entropy-encoding the quantized EA-GBT coefficient.

Abstract: The present invention provides a method for performing a transform, the method comprising the steps of: deriving a row transform set, a column transform set, and a permutation matrix on the basis of a given transform matrix (H) and error tolerance parameter; obtaining a row-column transform (RCT) coefficient on the basis of the row transform set, the column transform set, and the permutation matrix; and performing a quantization and an entropy encoding on the RCT coefficient, wherein the permutation matrix represents a matrix obtained by permutating a row of an identity matrix.

Abstract: The present invention, with respect to a method of processing video data, provides a method of processing video data, provides a method characterized by comprising the steps of: performing a clustering for the video data; generating at least one data cluster as a result of the clustering; generating at least one Graph laplacian matrix corresponding to the at least one data cluster; performing conversion optimization on the basis of multiple graph-based models, wherein the multiple graph-based models respectively include at least one graph laplacian matrix; and generating an optimized conversion matrix according to the results of performing the conversion optimization.

Abstract: The present invention provides a method for encoding a video signal by using a single optimized graph, comprising the steps of: obtaining a residual block; generating graphs from the residual block; generating an optimized graph and an optimized transform by combining the graphs, wherein the graphs are combined on the basis of an optimization step; and performing a transform for the residual block on the basis of the optimized graph and the optimized transform.

Abstract: A method for encoding a video signal includes: a step of selecting a transform parameter set via an optimization process for a target block, wherein the transform parameter set comprises a vertical transform set, a horizontal transform set and a transform order parameter set; a step of updating, on the basis of the selected transform parameter set, a transform block having a singleton coefficient, wherein the single ton coefficient represents a single coefficient obtained on the basis of the transform order parameter set; a step of obtaining a transform coefficient for the target block on the basis of the updated transform block; a step of quantizing the transform coefficient; and a step of entropy encoding the quantized transform coefficient.

Abstract: The present invention provides a method for encoding a video signal by using a single optimized graph, comprising the steps of: obtaining a residual block; generating graphs from the residual block; generating an optimized graph and an optimized transform by combining the graphs, wherein the graphs are combined on the basis of an optimization step; and performing a transform for the residual block on the basis of the optimized graph and the optimized transform.