An image processing apparatus includes an input control unit that receives an input of image data and a first image-processing unit that performs first image processing on image data received from an image reading unit thereby obtaining first-processed image data. A first output control unit selectively-outputs the first-processed image data to any of the input control unit and an external storage unit. A second image-processing unit receives the first-processed image data from the input control unit and performs second image processing on the first-processed image data thereby obtaining second-processed image data, and a second output control unit outputs the second-processed image data.