This invention provides an image encoding apparatus operable to encode RAW image data obtained from a capturing sensor that has a color filter array in which a plurality of filters for each of three primary colors and a plurality of filters for a specific color for luminance are arranged in an N×N pixel region, where the image encoding apparatus comprises a conversion unit which converts the RAW image data into a plurality of planes each configured by a single color component; and an encoding unit which encodes each of the planes, wherein the conversion unit, for each component representing the three primary colors, by referencing pixel values of the same component in the N×N pixel region, generates a plane configured by a low-frequency component data and a plane configured by a high-frequency component.