IMAGE CODING SYSTEM

摘要

PURPOSE:To obtain a system converting input image data whose luminance is corrected while taking a characteristic of a display device or the like into account into a code suitable for obtaining a decoded image with less visual deterioration with respect to an original image at a high compression efficiency. CONSTITUTION:The image coder 1 uses a frequency characteristic correction section 11 and an inverse gamma correction section 12 to apply inverse luminance correction to input image data thereby once restoring the data into luminance data before the correction. A control section 13 applies orthogonal transformation or the like to the luminance data and a quantization section 14 applies quantization to a transformation coefficient. Then a variable length coding section 15 and a code generating section 16 are used to code the data and the coded data are sent to a transmission line. An image decoder 2 applies inverse generating processing to the coding to decode the image into an original image and it is outputted on a display device 34.