Intra Block-DPCM with Layer Separation of Screen Content in VVC

An intra coding algorithm with layer separation is proposed. This algorithm is designed on top of an adopted tool in VVC, called Block DPCM (BDPCM), and benefits from texture information in a neighborhood to derive intensity levels of background and foreground layers. This information is used to reduce large rate of residual in case of incorrect layer prediction by BDPCM. For this purpose, three inter-layer transition states are defined that are either implicitly or explicitly conveyed to the decoder. Once a transition is signaled, the decoder corrects the prediction value using the derived layer information. Experiments on screen contents show a BD-rate gain of about 10% percent over VVC Test Model (VTM) and 1% over the regular BDPCM, with the cost of computational complexity.