Coefficient Constraint LIC with ADMM

Local Intensity Compensation (LIC) is an intra-frame motion compensation for video coding, and was a candidate for HEVC. LIC compensates a target block using motion vectors of reference blocks and linear coefficients of the blocks; thus, from a view point of data compression, not only compensation error but also the range of the motion vectors and coefficients should be as small as possible. Our previous work employs Alternating Direction Method of Multipliers (ADMM) to obtain reference blocks and their coefficients of LIC. This paper proposes to limit the range of coefficients, and experimental results tell us that the proposed method shows almost equivalent compensation accuracy to the conventional method.