An image decoding method according to the present document may comprise the steps of: deriving a first variable indicating whether there is a valid coefficient in a region excluding a DC region from a current block; deriving a second variable indicating whether there is a valid coefficient in a second region excluding a first region formed at the upper left end of the current block; when the first variable indicates that the valid coefficient exists in the region excluding the DC region, and the second variable indicates that the valid coefficient does not exist in the second region, parsing an LFNST index from the bitstream; and applying an LFNST matrix derived on the basis of the LFNST index to transform coefficients in the first region, to derive the modified transform coefficients.

In one embodiment, an apparatus comprises a storage device and a processor. The storage device stores a plurality of images captured by a camera. The processor: accesses visual data associated with an image captured by the camera; determines a tile size parameter for partitioning the visual data into a plurality of tiles; partitions the visual data into the plurality of tiles based on the tile size parameter, wherein the plurality of tiles corresponds to a plurality of regions within the image; compresses the plurality of tiles into a plurality of compressed tiles, wherein each tile is compressed independently; generates a tile-based representation of the image, wherein the tile-based representation comprises an array of the plurality of compressed tiles; and stores the tile-based representation of the image on the storage device.

A method for decoding an encoded video bit stream in a video decoder is provided that includes determining a scan pattern type for a transform block to be decoded, decoding a column position X and a row position Y of a last non-zero coefficient in the transform block from the encoded video bit stream, selecting a column-row inverse transform order when the scan pattern type is a first type, selecting a row-column inverse transform order when the scan pattern type is a second type, and performing one dimensional (1D) inverse discrete cosine transformation (IDCT) computations according to the selected transform order to inversely transform the transform block to generate a residual block.

A method for decoding an encoded video bit stream in a video decoder is provided that includes determining a scan pattern type for a transform block to be decoded, decoding a column position X and a row position Y of a last non-zero coefficient in the transform block from the encoded video bit stream, selecting a column-row inverse transform order when the scan pattern type is a first type, selecting a row-column inverse transform order when the scan pattern type is a second type, and performing one dimensional (1D) inverse discrete cosine transformation (IDCT) computations according to the selected transform order to inversely transform the transform block to generate a residual block.

This application relates to the image processing field, and provides an encoding method and an encoder. The method includes: determining an encoding quantization parameter QP; precoding a to-be-encoded block by using the encoding QP to obtain encoding result information; adjusting the encoding QP based on the encoding result information; and performing real encoding on the to-be-encoded block by using an adjusted encoding QP. This can improve image compression performance.

A program for generating a significant video stream causes a computer to function as coding parameter extraction means for extracting a coding parameter of each macroblock for each frame from an original video stream, macroblock selection means for selecting a significant macroblock that has a coding parameter satisfying a predetermined condition, and significant video stream generation means for generating a significant video stream in which frames of the original video stream temporally synchronized with the frames of the coding parameter in the significant macroblocks are combined in time series.

There are disclosed techniques for block wise encoding and decoding. The techniques may be applied to encoders, decoders, and methods for encoding and/or decoding. In one example, there is provided a technique to decode (resp. decode) a predetermined block of the picture by assigning, based on a first signalization in the data stream, the predetermined block to the first set or the second set, sorting the assigned set of intra-prediction modes according to intra-prediction modes used for neighboring blocks, neighboring the predetermined block, to obtain a list of intra prediction modes, deriving, for the predetermined block, from the data stream, an index into the list of intra prediction modes, predicting the predetermined block using an intra prediction mode onto which the index points. The decoder (resp. encoder), if the assigned set is the first set of intra-prediction modes, in sorting the assigned set, uses a second mapping which maps each intra-prediction mode of the second set of prediction modes onto a representative one in the first set of intra-prediction modes.

There are disclosed techniques for block wise encoding and decoding. The techniques may be applied to encoders, decoders, and methods for encoding and/or decoding. In one example, there is provided a technique to decode (resp. decode) a predetermined block of the picture by assigning, based on a first signalization in the data stream, the predetermined block to the first set or the second set, sorting the assigned set of intra-prediction modes according to intra-prediction modes used for neighboring blocks, neighboring the predetermined block, to obtain a list of intra prediction modes, deriving, for the predetermined block, from the data stream, an index into the list of intra prediction modes, predicting the predetermined block using an intra prediction mode onto which the index points. The decoder (resp. encoder), if the assigned set is the first set of intra-prediction modes, in sorting the assigned set, uses a second mapping which maps each intra-prediction mode of the second set of prediction modes onto a representative one in the first set of intra-prediction modes.

The present invention generally relates to a technology of effectively performing video analysis of a compressed video (e.g., H.264 AVC, H.265 HEVC) in a video analysis system. More specifically, the present invention relates to a video analysis technology of a compressed video (e.g., CCTV video) in which branching in the video analysis process is performed with referring to motion vectors which have been obtained by parsing the compressed video, so that computing resource for the video analysis of the compressed video may be lowered. The present invention may provide an advantage of lowering the computer resource which is required for analyzing a compressed video (e.g., CCTV video).

The present invention provides a method for decoding a video signal including extracting an inter prediction mode of a current block from the video signal; generating two non-square prediction blocks using two motion vectors according to the inter prediction mode; performing a non-square transform on the two non-square prediction blocks to obtain two non-square prediction blocks on a frequency domain; updating the two non-square prediction blocks on the frequency domain using a correlation coefficient or a scaling coefficient; and generating a reconstruction block based on the updated non-square prediction blocks on the frequency domain and a residual block.