New image processing method for phase plate diffraction image

The principle of measuring large scale form and position errors using CCD detector, laser diode fiber and phase plate alignment technique was introduced. According to the characters of phase plate diffraction image, a new image processing method projecting method was proposed. Compared with the mean method in time, the projecting method uses the mean method in space. So the method can eliminate the effect of interference fringe introduced by the window glass of a CCD and also the air turbulence is restrained. Because the projecting can make a two-dimension image changed into two one-dimension images, so the data processing is very fast.