公开(公告)号：US10484695B2

公开(公告)日：2019-11-19

申请号：US15798495

申请日：2017-10-31

Applicant: GOOGLE LLC

Inventor： Joseph Young ,  Dake He

IPC: H04N19/159 ,  H04N19/176 ,  H04N11/02 ,  H04N19/129 ,  H04N19/18 ,  H04N19/60 ,  H04N19/13 ,  H04N19/124 ,  H04N19/44 ,  H04N19/91 ,  H04N19/122

Abstract: Coding using level maps is disclosed. A method includes coding a scan position, in a forward scan direction, corresponding to an end-of-block and coding, in a backward scan direction, a non-zero map indicating positions of the transform block containing non-zero transform coefficients. The method also includes coding, in the backward scan direction, lower-range level maps, each lower-range level map having a respective map level up to a maximum map level, the lower-range level map indicating which absolute values of the non-zero transform coefficients are equal to the respective map level and which absolute values of the non-zero transform coefficients are greater than the respective map level. The method also includes coding a coefficient residual map, each residual coefficient of the coefficient residual map corresponding to a respective non-zero transform coefficient of the transform block having an absolute value exceeding the maximum map level.