Image capturing apparatus having a function for encoding raw image control method therof, and non-transitory computer-readable storage medium

Abstract

This invention provides an apparatus having an image capturing unit, a transforming unit which transforms RAW image obtained by the image capturing unit into a plurality of channels, and an encoder which performs a frequency transformation, quantization, and encoding for each channel, where the apparatus comprises a classifying unit which, based on a sub-band of a low-frequency component obtained by the frequency transformation for a channel, in which a luminance component is predominant, obtained by the transforming unit, classifies a luminance of each region in a case where one screen is divided into a plurality of regions; and an estimation unit which, for each luminance, computes an index value representing a degree of difference between data before/after the quantization for each region, and estimates an image quality based on the index value.