Apparatus for and method of making measurement on printed sheet

A printed sheet measurement apparatus initially captures images on a reference sheet and a printed sheet to store respective image data. Next, both of the image data are displayed on a display element, and a pair of corresponding points are specified for each of the image data. A judgment is made as to whether or not the pair of corresponding points on each of the images are spaced at least a predetermined distance apart from each other. If not, the corresponding points are specified again. After the corresponding points are determined, the coordinates of the corresponding points are stored. The coordinates of an objective point at which a colorimetric value is to be computed is computed based on the corresponding points. Next, a colorimetric value on the coordinates is measured. Thus, the printed sheet measurement apparatus measures the calorimetric values in precisely corresponding positions on the respective images if there is a difference in coordinate relationship between the reference sheet and the printed sheet.