The image processing apparatus includes a determining part configured to determine, from a difference between information on color of a first pixel in a first image and information on color of a second pixel corresponding to the first pixel in a second image, whether or not the first image includes color blur due to defocus, the first and second images being generated by an image-pickup system and whose focus states are mutually different. The apparatus further includes a correcting part configured to perform on the first image a correction process that corrects the color blur determined by the determining part.