METHOD AND DEVICE FOR COMPRESSING IMAGE, IMAGE COMPRESSION PROGRAM AND IMAGE PROCESSOR

• Main Authors: MORIYA KAZUYOSHI, TOKUNAGA TAKAHARU, KAWAMURA MIYUKI
• Format: Patent
• Language: English
• Published: 20.03.2003
• Edition: 7
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PROBLEM TO BE SOLVED: To provide an image compressing method capable of performing reversible compression about a transparent color while performing reversible compression of the entire image information with a value representing transparence allocated as a pixel value. SOLUTION: Input image information is used to divide an input image into a plurality of pixel blocks, and reversible AOT coding is subsequently applied to each pixel in each pixel block. In the case the entire pixels in the AOT coded pixel block are transparent or non-transparent, a discrimination code αCC=0 or 1 is outputted. In the case transparent pixels and non-transparent pixels are mixed and also, the transparence/non-transparence of each pixel can be discriminated with a threshold, a discrimination code CC=α2 and a threshold M are outputted. In the case transparent pixels and non-transparent pixels are mixed and also, the transparence/non-transparence of each pixel can not be discriminated with the threshold, a discrimination code αCC=3 and data showing the transparence/non-transparence of the entire pixels are outputted.