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In order to get continuous and one-point-width of edge line, a method for noise-supprssion in accordance with rough extent of image is presented. After getting the edge lineby way of wavelets transform, a suit of improvements for edge line is established and adopted. Finally, a satisfied result is obtained with piece grain image segmented successfully.

In 3D projecting grating profilometry, we are often persecuted by some disgusted phenomenon of images, such as reflecting flare, overlapping of grating and other noise. All these can bring a bigger error in image processing. The intention of this paper is to propose some special filter and other methods of image processing. The technique we applied is based on peculiarity of projecting grating profilometry image, which has obvious directionality. We used the nonsymmetrical multi band-pass filters to reject the high frequency noise along the grating and other component except base frequency part. The result obtained from the processed image by multi band-pass filter is much better than that from primary image. The method is propitious to measure some smooth surfaces.

The shift step must be an accurate value in the traditional algorithm of phase-measuring profilometry technology, the result error is found in unequal step-shifting in which one or more step is not the accurate value. So the phase shifter is expensive to meet the high precision. In this paper, the software is made to give a chart of error phase in any unequal step phase-shifting, and a calibration algorithm is presented to give the correct phase based on this error-phase chart. With the help of computer emulator written by us, the calibration algorihtm based on checking proved to be correct. So the precise request of phase shifter is reduced greatly.

The surface profile is presented various, that forming cause of the specific trace is different. The specific trace is distributed as two types, from its criterion. First, the criterion of the specific trace is large, surpass a millimeter, is called grand specific trace; Second, the criterion is small, more or less the same length micron, is called micron specific trace. Using projection, contracting beam micrography, two-dimensions adusting image mode exchange, low-pass filter off noise, wavelet, and intelligent mode phase reconstruction, the surface profile of recognizing specific trace is given exactly and rapidly, that is a new optical image processing technology in recognition and diagnosis. This paper introduces the speciality above the technology and gave typical examples.

This paper described principle of some projection technologies, attached importance to some measurement technologies in engineering and measurement in complicated profile of fine-micro body. The optoelectronical system and the image processing system are supplied. The typical measurement result are obtained. It is proven that the projection technology is a composite technology, which has extensive applications in many ways.