Research On Optical Implementation Method Of Non-sampled Direction Filtering

Optical non-sampled directional filtering is an application method combinating optical information processing and non-sampled direction filtering theory. It gives full play to the superiority of parallelism, high speed, large capacity, small size and other advantages about photon optical information processing technology. More importantly,the multi-directional filtering can reduce time consuming, which has important theoretical and practical value.Based on the theory of directional filter, its basic concepts, structures and several examples have been introduced. Then we describe the concept of non-sampled directional filter, and analysis the advantages or disadvantages between the non-sampled filter and sampled filter according to related theory. Finally is generated a non-sampled filter bank of eight directional decomposition and reconstruction. In order to introduce the concept of non-sampled contourlet transform, which provides the theoretical basis for optical non-sampled directional filter and optical non-sampled contourlet filter, we combine the theories of the non-sampled directional filter bank and non-sampled pyramid filter bank.The 4 f system is an important optical path for the realization of optical non-sampled direction filter and optical non-sampled contourlet transform. According to the principles of Fourier optics, we analyze the basic principles and structures of 4 f system and construct the 4 f system which is needed by optical non-sampled direction filter and optical non-sampled contourlet transform. On the one hand, considering the frequency characteristics of the image space, the limited scope of space filter and the system noise, the restrictive conditions on the sizes of input image, filter image and output image were given. On the other hand, the image loading equipment and image acquisition equipment have special requirements in terms of the time domain filter and frequency domain filter. So we split and storage time domain filter, correct 、normalize and quantization the frequency domain filter respectively. Then the final form of optical filter were given. Finally, the feasibility of filter has been demonstrated by system simulation and optical experiment.