公开(公告)号：US20220094951A1

公开(公告)日：2022-03-24

申请号：US17029730

申请日：2020-09-23

Applicant: ATI TECHNOLOGIES ULC

Inventor： Wei GAO ,  Yang LIU ,  Ihab AMER ,  Ying LUO ,  Shu-Hsien Samuel WU ,  Edward HAROLD ,  Feng PAN ,  Crystal SAU ,  Gabor SINES

IPC: H04N19/186 ,  H04N19/119 ,  H04N19/176 ,  H04N19/30 ,  H04N19/136 ,  H04N19/147 ,  H04N19/96

Abstract: An encoder encodes an image portion by recursively partitioning the portion into a partitioning hierarchy of levels. The top level has a single block representing the entire portion and each lower level has four smaller blocks representing a corresponding larger block at a higher level. A palette table is generated for each bottom-level block based on the pixels of the associated block. For each successively higher level, the encoder generates a palette table for each current-level block by selecting palette colors based on the palette colors from the four palette tables for the associated four blocks at the next-lowest level. A color index map is then generated based on a final palette table selected from the palette tables generated for the partitioning hierarchy. A representation of the portion is then encoded using the final palette table and the color index map to generate a corresponding segment of an encoded bitstream.