Image encoding apparatus, image decoding apparatus, control methods thereof, and non- transitory computer-readable storage medium

Abstract

An encoding apparatus comprises a dividing unit that divides RAW image data into a plurality of tiles, a generating unit that generates planes of a plurality of channels having mutually-different components for each of the tiles, a transforming unit that frequency-transforms the plane of each channel and generates sub-band data of a plurality of resolution levels, a controller that divides each of the plurality of sub-band data into the same number of segments to divide the sub-band data into a plurality of segments corresponding to the same regions, and determines first quantization parameters common for the plurality of sub-band data in each segment, a quantizing unit that, based on the determined first quantization parameters, quantizes each sub-band data, and an encoder that encodes a quantization result on a sub-band-by-sub-band basis.