To provide an image coding system that shifts up bits denoting a converted signal with a prescribed frequency band to encode each tile resulting from dividing an image into a plurality of tiles where a target area and non- target areas are intermingled with each other.
The image coding system is provide with a tile division section 2 that divides an image into tiles, a ROI decision section 3 that discriminates a target area in the image, a tile classification section 4 that classifies each of the tiles depending on whether each tile belongs to the discriminated target area or not, a discrete wavelet transform section 5 that transforms each of the tiles into a signal with frequency bands, and an entropy coding section 8 that designates any of a plurality of conversion coefficients corresponding to a tile classified to be partly included in the ROI by the tile classifications section and subjected to discrete wavelet transform, applies bit shift-up to the bit denoting the designated conversion coefficient with a prescribed frequency band for quantization and applies entropy coding to the quantized data for encoding.
SATO MAKOTO
KAJIWARA HIROSHI
