1. A color image encoding method using residue transform for encoding an original color image formed with at least two or more components, the method comprising: obtaining, for each component of the original color image, a residue corresponding to the difference of the original color image and a predicted image generated from a restored image; selecting whether or not to transform the residue by using a relation between residues of respective components of the original color image; and transforming the residue and encoding the transformed residue if the transforming of the residue is selected, or if the transforming of the residue is not selected, encoding the obtained residue, wherein the encoding of the obtained residue includes at least quantization.