IMAGE ENCODING METHOD AND IMAGE DECODING METHOD

摘要

An image encoding method including the following: an acquisition step (S101) in which image-format information is acquired; a determination step (S102) in which a luminance-signal subsampling method is determined; a storage step (S103) in which said subsampling method is stored in a memory; an acquisition step (S104) in which the subsampling method is acquired from said memory; a first subsampling step (S105) in which luminance signals for surrounding pixels are subsampled; a computation step (S106) in which parameters for a linear model are computed using the subsampled luminance signals and color differences for the surrounding pixels; a second subsampling step (S107) in which the luminance signals for a block to be encoded are subsampled; and a computation step (S108) in which predicted color differences for the block to be encoded are computed using said subsampled luminance signals and the aforementioned linear-model parameters.