Adaptive reshaping for next generation video codec

Various earlier work in MPEG/JCTVC have shown that out-loop reshaping, which modifies the video signal in preprocessing before encoding and post-processing after decoding in an end-to-end video compression workflow, can improve subjective quality of coded High Dynamic Range (HDR) and Wider Color Gamut (WCG) content compressed using HEVC. However, the requirement of not making normative changes to the HEVC specification has significantly constrain the design and optimization of the reshaper. In April 2018, The Joint Video Experts Team (JVET) has launched a project to develop a new video coding standard to be known as Versatile Video Coding (VVC). This opens the door to exploit possibilities of the reshaper design inside of the core video codec. In this paper, an in-loop architect of reshaper is presented. Preliminary results suggest that the in-loop reshaping architect can retain the functionality of out-loop reshaper. In addition, the in-loop design can resolve many limitations of the out-loop design and can be used as a general coding tool for general video content not limited to HDR.