PURPOSE: To provide the computer image system with which images having high image quality are obtainable and printing block copies are easily formable.

CONSTITUTION: Two kinds of image data; low-resolution data and high-resolution data, of the same images are prepd. for the image data, such as color image data and line drawing data. A design operation is carried out by using the low-resolution image data. The data is replaced with the high-resolution data for printing after production of a sample. The printing block copy is thus produced.