The coding efficiency of scalable video coding is increased by substituting missing spatial intra prediction parameter candidates in a spatial neighborhood of a current block of the enhancement layer by use of intra prediction parameters of a co-located block of the base layer signal. By this measure, the coding efficiency for coding the spatial intra prediction parameters is increased due to the improved prediction quality of the set of intra prediction parameters of the enhancement layer, or, more precisely stated, the increased likelihood, that appropriate predictors for the intra prediction parameters for an intra predicted block of the enhancement layer are available thereby increasing the likelihood that the signaling of the intra prediction parameter of the respective enhancement layer block may be performed, on average, with less bits.

The coding efficiency of scalable video coding is increased by substituting missing spatial intra prediction parameter candidates in a spatial neighborhood of a current block of the enhancement layer by use of intra prediction parameters of a co-located block of the base layer signal. By this measure, the coding efficiency for coding the spatial intra prediction parameters is increased due to the improved prediction quality of the set of intra prediction parameters of the enhancement layer, or, more precisely stated, the increased likelihood, that appropriate predictors for the intra prediction parameters for an intra predicted block of the enhancement layer are available thereby increasing the likelihood that the signaling of the intra prediction parameter of the respective enhancement layer block may be performed, on average, with less bits.

A method for decoding a data stream representative of an image split into blocks. The method includes: for a current block, determining whether the size of the current block is less than or equal to a threshold, and if so, decoding information indicating a coding mode of the block among first and second coding modes, and reconstructing the current block according to the indicated coding mode, and otherwise reconstructing according to the first coding mode. According to the first coding mode, the current block is reconstructed using an inverse transform of a transformed prediction residue decoded for the current block, and according to the second coding mode the current block is reconstructed, for each pixel, by obtaining a prediction of the pixel from another previously decoded pixel belonging to the current block or to a previously decoded block, and reconstructing the pixel from the prediction and a decoded prediction residue.

Given a sequence of images in a first codeword representation, methods, processes, and systems are presented for integrating reshaping into a next generation video codec for encoding and decoding the images, wherein reshaping allows part of the images to be coded in a second codeword representation which allows more efficient compression than using the first codeword representation. A variety of architectures are discussed, including: an out-of-loop reshaping architecture, an in-loop-for intra pictures only reshaping architecture, an in-loop architecture for prediction residuals, and a hybrid in-loop reshaping architecture. Syntax methods for signaling reshaping parameters, and image-encoding methods optimized with respect to reshaping are also presented.

A lossy method of compressing data, such as image data, which uses wrap-around wavelet compression is described. Each data value is divided into two parts and the first parts, which comprise the most significant bits from the data values, are compressed using wrap-around wavelet compression. Depending upon the target compression ratio and the compression ratio achieved by compressing just the first parts, none, one or more bits from the second parts, or from a data value derived from the second parts, may be appended to the compressed first parts. The method described may be lossy or may be lossless. A corresponding decompression method is also described.

A lossy method of compressing data, such as image data, which uses wrap-around wavelet compression is described. Each data value is divided into two parts and the first parts, which comprise the most significant bits from the data values, are compressed using wrap-around wavelet compression. Depending upon the target compression ratio and the compression ratio achieved by compressing just the first parts, none, one or more bits from the second parts, or from a data value derived from the second parts, may be appended to the compressed first parts. The method described may be lossy or may be lossless. A corresponding decompression method is also described.

Embodiments of this application provide a video transmission method, apparatus, and system, to reduce an end-to-end transmission delay of video data. The method includes: A transmit end obtains a first frame of image of the video data, where the first frame of image includes a plurality of sub-images, and the plurality sub-images include a first sub-image and a second sub-image; the transmit end performs layered encoding on the first sub-image to obtain a plurality of layers of bitstreams of the first sub-image; the transmit end sends the plurality of layers of bitstreams of the first sub-image to a receive end; the receive end decodes the plurality of layers of bitstreams of the first sub-image to obtain the first sub-image.

There are included a data processing unit that trains a neural network; and an encoding unit that generates encoded data in which model header information that identifies a model of the neural network, layer header information that identifies a layer of the neural network, and layer-by-layer edge weight information are encoded.

Examples described herein relate to decoding and encoding signals. A method of performing signal enhancement operations on one or more portions of a signal is described, wherein the performing is based at least in part on information embedded in one or more values received in one or more encoded data layers transmitted within a stream of encoded data, and wherein said values are associated with transformed coefficients intended to be processed by a decoder for deriving elements of the signal, wherein the information indicates an impairment associated with a portion of the signal.

Examples described herein relate to decoding and encoding signals. A method of performing signal enhancement operations on one or more portions of a signal is described, wherein the performing is based at least in part on information embedded in one or more values received in one or more encoded data layers transmitted within a stream of encoded data, and wherein said values are associated with transformed coefficients intended to be processed by a decoder for deriving elements of the signal, wherein the information indicates an impairment associated with a portion of the signal.