An image coding apparatus for coding RAW data of an image of a Bayer array separates the RAW data respectively into separate planes of data of a plurality of color components constituting the Bayer array, determines a coding method for coding each plane from a plurality of coding methods, generates a coding parameter on the basis of the determined coding method, and codes each plane on the basis of the generated coding parameter, wherein when a coding-target plane is a plane to be coded later among the plurality of planes of the same color, a coding parameter for coding the plane to be coded later is generated by using a result of the coding of the plane to be coded earlier among the plurality of planes of the same color.