IMAGE ENCODING METHOD, IMAGE DECODING METHOD, IMAGE ENCODER, IMAGE DECODER, IMAGE ENCODING PROGRAM AND IMAGE DECODING PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide an image encoding method capable of automatically establishing an operation expression of a filter.SOLUTION: An image encoding method which encodes an input image signal comprises: a filter generation step in which an operation expression of an image quality improvement filter used inside an encoding loop is adaptively configured for each input image signal using genetic programming; encoding step in which operational expression is encoded; a filtering step in which filter processing is performed to the input image signal with an operational expression of an image quality improvement filter; estimating step in which an encoding amount R for expressing procedure of adaptive configuration is estimated; a deriving step in which a square error sum D between original images is derived based on a restoration image and an input image signal derived by using an operational expression; and a cost calculation step in which lagrange cost C is obtained by C=D+λR using lagrange undetermined multiplier λ, and minimization standard when adaptively configuring the image quality improvement filter is the lagrange cost C.