Because the 3-D shape measurement technique using optimal intensity-modulation pattern projection (OIMP)
method can detect a lot of stripes numbers by one projection, the application is expected by the spread of the digital
camera and the pattern projector. However, there is a problem that the accuracy of stripes recognition decreases in the
case of the intensity range of the observation image of the measurement object is insufficient. Or since two images are
needed to convert the observation image by the image correction method, saying, OIMP method, the measurement time
is long. In order to solve above problem, we propose an image analysis method based on Fourier transform technique to
correct the intensity of the observation image. By this method, the stripes can be extracted only using a single
observation image, and then, a fast 3-D shape measurement is realizable.