A method of multi-scale neural image compression with intra-prediction residuals is performed by at least one processor and includes downsampling an input image, generating a current predicted image, based on a previously-recovered predicted image, and generating a prediction residual based on a difference between the downsampled input image and the generated current predicted image. The method further includes encoding the generated prediction residual, decoding the encoded prediction residual, and generating a currently-recovered predicted image based on an addition of the current predicted image and the decoded prediction residual. The method further includes upsampling the currently-recovered predicted image, generating a scale residual based on a difference between the input image and the upsampled currently-recovered predicted image, and encoding the scale residual.

A method, computer program, and computer system is provided for video encoding and decoding. Video data including one or more frames is received. One or more quantization parameters associated with the received video data are determined for frame generation or enhancement of a target frame from among the one or more frames. The video data is decoded based on the determined quantization parameters.

Methods, systems, and devices for coefficient scaling for high-precision image and video coding are described. A example method of video processing includes performing a conversion between a current block of a video and a bitstream representation of the video according to a rule, wherein the rule specifies that the conversion includes during encoding, skipping applying a forward transform to residual coefficients of the current block prior to including in the bitstream representation, or during decoding, reconstructing residual coefficients of the current block from the bitstream representation without applying an inverse transform, and wherein the rule further specifies that a scale factor is applied to the residual coefficients independent of a size of the current block.

Methods, systems, and devices for coefficient scaling for high-precision image and video coding are described. A example method of video processing includes performing a conversion between a current block of a video and a bitstream representation of the video according to a rule, wherein the rule specifies that the conversion includes during encoding, skipping applying a forward transform to residual coefficients of the current block prior to including in the bitstream representation, or during decoding, reconstructing residual coefficients of the current block from the bitstream representation without applying an inverse transform, and wherein the rule further specifies that a scale factor is applied to the residual coefficients independent of a size of the current block.

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.

Methods and systems for frame rate scalability are described. Support is provided for input and output video sequences with variable frame rate and variable shutter angle across scenes, or for input video sequences with fixed input frame rate and input shutter angle, but allowing a decoder to generate a video output at a different output frame rate and shutter angle than the corresponding input values. Techniques allowing a decoder to decode more computationally-efficiently a specific backward compatible target frame rate and shutter angle among those allowed are also presented.

Methods and systems for frame rate scalability are described. Support is provided for input and output video sequences with variable frame rate and variable shutter angle across scenes, or for input video sequences with fixed input frame rate and input shutter angle, but allowing a decoder to generate a video output at a different output frame rate and shutter angle than the corresponding input values. Techniques allowing a decoder to decode more computationally-efficiently a specific backward compatible target frame rate and shutter angle among those allowed are also presented.

In a method and a device for encoding or decoding an image according to the present invention, motion information for bidirectional prediction of a current block may be derived on the basis of an inter mode previously defined in the device for encoding or decoding an image, and inter prediction may be performed on the current block on the basis of the motion information, wherein the motion information for bidirectional prediction is adjusted to be motion information for unidirectional prediction according to the predefined inter mode.

A video data stream having a video encoded thereinto is provided. The video data stream comprises an indication that indicates whether or not one or more scalable nesting supplemental enhancement information messages comprising timing information for each of one or more output layer sets are present within the video data stream.

A video data stream having a video encoded thereinto is provided. The video data stream comprises an indication that indicates whether or not one or more scalable nesting supplemental enhancement information messages comprising timing information for each of one or more output layer sets are present within the video data stream.