Image encoding apparatus and control method therefor

Abstract

An image encoding apparatus includes a plane conversion unit which generates, from image data of one frame of the moving image data, a plurality of planes each formed from a single component, a frequency conversion unit which generates a plurality of subbands for each plane by performing frequency conversion for each plane, a quantization unit which quantizes coefficients in each subband using a quantization parameter, an encoder which encodes the quantized coefficient data, and a control unit which updates the quantization parameter so that a code amount of the encoded data becomes equal to a target code amount set for each plane. The control unit updates the quantization parameter by accumulating a difference between the target code amount set for each plane and a generated code amount of each plane, and distributing the accumulated differences to the plurality of planes.