An image correcting personal computer displays on its monitor a correction screen consisting of a main display area, a sub display area and a parameter adjusting area. The main display area is divided into a plural number of split image display sections displaying split images corresponding to the same fragment of an image to correct. The split image display sections may display the split images in conditions corrected differently from each other, by changing the correction parameters on the parameter adjusting area while selecting one of the split image display sections, except a referential display section that displays the split image in default conditions corrected with fixed correction parameter values.