The Research On Processing Technology Of Laser Interference Pattern

With the development of the high accurate measurement technology of the image, the image processing technology plays an important part in high accurate measurement. The theories, methods and techniques related to image processing technology are investigated in this dissertation, which mainly include image preprocessing, sub-pixel locating and the application in multi-degree of freedom measurement. The main works and contributions obtained in this dissertation include as follows:1. Summarize the common image pre-processing methods and point out their merits and faults. Discuss the boundary effect of Gaussian Low-Pass Filtering(GLPF). To improve it, the zero-order Gaussian Filtering for an Open Profile(GFO) is used.2. Analyze the spin-filer algorithm which is widely used in interference figure processing. Utilizing the low-pass filter combined with the GFO, the orientation diagram could be calculated accurately.3. Summarize the common sub-pixel algorithm and inject the robust estimation algorithm into sub-pixel locating. In the displacement measurement based on the principle of laser interference, the Gaussian quadrics fitting algorithm is used to fix the central position of facula and raise the location accuracy.4. Analyze the measurement of length based on laser interference. In its measurement, the interference fringe should be tracked and counted. To avoid its disadvantage, a novel method of length measurement based on two sphere waves'interference is been introduced. The simulation results shows that the measurement could be high accurate in a short range. At last, the paper discuss the multi-degrees of freedom measurement based on laser interference.