Method on warp delta signaling improvements

Abstract

Systems and methods for encoding and decoding using warp motion modes are provided. A method includes receiving a bitstream that includes a coded picture; obtaining warp information that is signaled in the bitstream, the warp information including a warp type indicating a number of parameters to be corrected by delta values, the number of parameters defining warp motion for predicting a current block of the coded picture; obtaining at least one delta value from the bitstream that is a delta of at least one parameter that defines the warp motion for predicting the current block; obtaining a warp model based on the warp information and the at least one delta value; and predicting the current block by performing warped motion compensation using the warp model.