To compress image information quantity while suppressing deterioration in an image.
An orthogonal transform section 2 applies orthogonal transform to an image signal divided into blocks each comprising a plurality of pixels to output orthogonal transform coefficient, an area division section 7 divides the orthogonal transform coefficient from a scan section 3 into a plurality of frequency areas, adders 8a to 8d calculate a sum of absolute values of the orthogonal transform coefficients by each of a plurality of divided frequency areas, a threshold value setting section 9 sets a threshold value used for threshold value processing on the basis of the absolute sum of the orthogonal transform coefficients by each frequency area, a threshold value processing section 4 executes the threshold value processing for the orthogonal transform coefficient from the scan section 3 on the basis of the set threshold value to compress the orthogonal transform coefficient.
HATTORI SHINICHI
OBARA EIJI
ASANO KENICHI
SATO HIDENORI
NEMOTO AYAKO
MOTOYAMA NOBUAKI
