A new projection pattern control technique is presented in an attempt to solve the problem whereby an image having an ideal intensity distribution cannot be photographed when measurement conditions, such as object color or object surface reflection, change. The proposed technique can adjust the intensity distribution of a projection pattern automatically, according to changes in the measurement conditions. An image with an ideal intensity distribution can then be obtained in a short time, approximately three projections on average. Thus, the speed, robustness, and practicality of 3-D image measurement can be improved.