Encoding and decoding residual image data using probabilistic models

摘要

A method of encoding video data comprises encoding video data having a first resolution in conformity with HEVC 13 to obtain video data of a base layer 14 and decoding the base-layer video data in conformity with HEVC 15. The decoded base-layer video data is up sampled 16 to generate decoded video data having a second resolution higher than the first resolution. A difference is formed 17 between the generated decoded video data having the second resolution and the original video data to generate data of a residual image. The residual-image data is compressed 18, 19 to generate video data of an enhancement layer 20. The compression of the residual data does not involve temporal or spatial prediction but is carried out by the application of a discrete cosine transform to the data and the employment of a parametric probabilistic model of the discrete cosine transform coefficients. This parametric model is then used to choose quantisers from a pool of available quantisers for quantizing the residual data. The method can be used to provide a Ultra high definition (UHD) codec with low complexity based on scalable encoding.