IMAGE ENCODER, IMAGE DECODER, AND COMPUTER-READABLE RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an image encoder and decoder by which a maximum compression rate can be obtained with image quality at a visually prescribed level or more. SOLUTION: The image encoder is characterized by having the an area image generating processing means that uses a received image and an area division image to conduct generating processing of each area image, an area division image coding processing means that applies encoding processing to the area division image based on a reversible compression system to generate area division image encoding data, a 1st area image encoding means that encodes an image of a prescribed area divided by the area division processing means based on an irreversible compression system, a 2nd area image encoding means that applies image encoding to the other area based on the image quality being a requirement and an encoded data coupling processing means that couples the area division image encoding data to the encoded data of each area into one set of encoded data.