Linearly coded profilometry with a coding light that has isosceles triangle teeth: Even-number-sample decoding method

A new triangulation-based optical profilometry-linearly coded profilometry (LCP)-is presented. In this method, a linear coding technique is introduced. It uses a periodic sawtoothlike structure light to code the surface being measured and the phase-shifting technique to decode the profile. A coding light that has isosceles triangle teeth is proposed. To realize the decoding, at least three samples are needed. When more than three samples are used, higher accuracy can be obtained. A decoding method of LCP with an even number of samples is provided. This method has been realized in my laboratory and the experimental results verify the reliability of LCP. Because the coding method used in LCP is simpler than that used in phase-measuring profilometry, LCP has a faster measuring speed. (C) 1997 Optical Society of America.