Disclosed herein are a video-decoding method and apparatus and a video encoding method and apparatus, and more particularly a method and an apparatus which perform region-differential image encoding/decoding using a recovered image. In accordance with an encoding method according to an embodiment, a recovered low-quality image is generated by performing encoding on an original image and a recovered high-quality image is generated using the recovered low-quality image. An image is segmented into multiple regions, and encoded reconstruction information for generating a reconstructed high-quality image is generated by performing encoding on the image.

Disclosed herein are a video-decoding method and apparatus and a video encoding method and apparatus, and more particularly a method and an apparatus which perform region-differential image encoding/decoding using a recovered image. In accordance with an encoding method according to an embodiment, a recovered low-quality image is generated by performing encoding on an original image and a recovered high-quality image is generated using the recovered low-quality image. An image is segmented into multiple regions, and encoded reconstruction information for generating a reconstructed high-quality image is generated by performing encoding on the image.

This application provides a method and apparatus for processing non-sequential point cloud media, a device, and a storage medium. The method includes: processing non-sequential point cloud data of a static object using a Geometry-based Point Cloud Compression (GPCC) coding scheme to obtain a GPCC bitstream; encapsulating the GPCC bitstream to generate an item of at least one GPCC region; encapsulating the item of the at least one GPCC region to generate at least one piece of non-sequential point cloud media of the static object; transmitting media presentation description (MPD) signaling of the at least one piece of non-sequential point cloud media; receiving a first request message transmitted by a video playback device; and transmitting first non-sequential point cloud media, the item of the GPCC region being used to represent a GPCC component of a three-dimensional (3D) spatial region corresponding to the GPCC region, and the non-sequential point cloud media including: an identifier of the static object, so that a user can purposefully request non-sequential point cloud media of a same static object a plurality of times, thereby improving the user experience.

This application provides a method and apparatus for processing non-sequential point cloud media, a device, and a storage medium. The method includes: processing non-sequential point cloud data of a static object using a Geometry-based Point Cloud Compression (GPCC) coding scheme to obtain a GPCC bitstream; encapsulating the GPCC bitstream to generate an item of at least one GPCC region; encapsulating the item of the at least one GPCC region to generate at least one piece of non-sequential point cloud media of the static object; transmitting media presentation description (MPD) signaling of the at least one piece of non-sequential point cloud media; receiving a first request message transmitted by a video playback device; and transmitting first non-sequential point cloud media, the item of the GPCC region being used to represent a GPCC component of a three-dimensional (3D) spatial region corresponding to the GPCC region, and the non-sequential point cloud media including: an identifier of the static object, so that a user can purposefully request non-sequential point cloud media of a same static object a plurality of times, thereby improving the user experience.

Various concepts which further improve multi-view/layer coding concepts, are described.

Various concepts which further improve multi-view/layer coding concepts, are described.

To mitigate some problems of the pixel color mapping being used in HDR video decoding of the type of SLHDR, a high dynamic range video encoding circuit (300) is taught, configured to encode a high dynamic range image (IM_HDR) of a first maximum pixel luminance (PB_C1), together with a second image (Im_LWRDR) of lower dynamic range and corresponding lower second maximum pixel luminance (PB_C2), the second image being functionally encoded as a luma mapping function (400) for decoders to apply to pixel lumas (Y_PQ) of the high dynamic range image to obtain corresponding pixel lumas (PO) of the second image, the encoder comprising a data formatter (304) configured to output to a video communication medium (399) the high dynamic range image and metadata (MET) encoding the luma mapping function (400), the functional encoding of the second image being based also on a color lookup table (CL(Y_PQ)) which encodes a multiplier constant (B) for all possible values of the pixel lumas of the high dynamic range image, and the formatter being configured to output this color lookup table in the metadata, characterized in that the high dynamic range video encoding circuit comprises: —a gain determination circuit (302) configured to determine a luma gain value (G_PQ) which quantifies a ratio of an output image luma for a luma position equal to a correct normalized luminance position divided by an output luma for the luma of the pixel of the high dynamic range image, wherein the high dynamic range video encoding circuit comprises a color lookup table determination circuit (303) configured to determine the color lookup table (CL(Y_PQ)) based on values of the luma gain value for various lumas of pixels present in the high dynamic range image. Similarly we teach how the same principles can be embodied in a SLHDR-type video decoder.

To mitigate some problems of the pixel color mapping being used in HDR video decoding of the type of SLHDR, a high dynamic range video encoding circuit (300) is taught, configured to encode a high dynamic range image (IM_HDR) of a first maximum pixel luminance (PB_C1), together with a second image (Im_LWRDR) of lower dynamic range and corresponding lower second maximum pixel luminance (PB_C2), the second image being functionally encoded as a luma mapping function (400) for decoders to apply to pixel lumas (Y_PQ) of the high dynamic range image to obtain corresponding pixel lumas (PO) of the second image, the encoder comprising a data formatter (304) configured to output to a video communication medium (399) the high dynamic range image and metadata (MET) encoding the luma mapping function (400), the functional encoding of the second image being based also on a color lookup table (CL(Y_PQ)) which encodes a multiplier constant (B) for all possible values of the pixel lumas of the high dynamic range image, and the formatter being configured to output this color lookup table in the metadata, characterized in that the high dynamic range video encoding circuit comprises: —a gain determination circuit (302) configured to determine a luma gain value (G_PQ) which quantifies a ratio of an output image luma for a luma position equal to a correct normalized luminance position divided by an output luma for the luma of the pixel of the high dynamic range image, wherein the high dynamic range video encoding circuit comprises a color lookup table determination circuit (303) configured to determine the color lookup table (CL(Y_PQ)) based on values of the luma gain value for various lumas of pixels present in the high dynamic range image. Similarly we teach how the same principles can be embodied in a SLHDR-type video decoder.

A video processing method includes performing a conversion between a video comprising a video unit and a bitstream of the video according to a rule. The rule specifies whether or how to include, in an adaptation parameter set (APS), information related to a scaling list of the video is based on a first syntax element. The first syntax element indicates whether the APS includes chroma component related syntax elements and is independent of one or more syntax elements in a sequence parameter set (SPS).

An image encoding apparatus comprises a selector configured to select a prediction operation, for prediction of samples of a current region of a current image with respect to one or more of a group of reference samples, from a set of candidate prediction operations, at least some of which define, as an intra-image prediction operation, a prediction direction between a current sample to be predicted and a group of reference samples in the same image; and an intra-image predictor configured to derive predicted samples of a current image region from reference samples of the same image in response to selection, by the selector, of an intra-image prediction operation for the current image region; in which: the current region comprises at least a subset of a current coding tree unit (CTU) in an array of CTUs; the group of references samples is disposed, with respect to the current image region at one or more predetermined sides of the current image region; and the selector is configured to inhibit the selection of a prediction operation for the current region, for which at least some of the reference samples at one or more of the predetermined sides of the current image region are disposed in a CTU other than the current CTU.