The Distortion Target Recognition Based On Maximum Average Correlation Height Algorithm

Detection of targets with cluttered background by hybrid optoelectronics correlator is the front technology in this field. The hybrid optoelectronics correlator combines the high-speed and the parallelism of the optical system with the controllable and programmable of the electronic system, so it has the advantage of high speed recognition and high positioning accuracy. The hybrid optoelectronics correlators include two forms, namely Joint transform correlator (JTC) and Vander Lugt Correlator (VLC). In the JTC, the recognition result of the target and template is a pair of the correlation peak, the location of the pair of correlation peak represents the relative position of the target and template. Therefore, by determining the location of the correlation peak, the position of the target can be determined. In the VLC, the recognition result of the target is a correlation peak. The target position can be determined by the position of the correlation peak.The target recognized by optical correlator is based on the principle of correlation matching. Only when the detected target is same as the pre-established template, the correlation peak will be output. If the target has the distortion (scale distortion or rotation distortion) relatively the template, the correlation peak will weaken rapidly, so that the target cannot be recognized.In this paper, started from the synthetic discriminant function, the distortion target recognition technology in the optical correlator is further researched. First, through the optimization of the existing Maximum Average Correlation Height filter, the scale invariant or rotation invariant recognition is achieved in the VLC.Second, the method of combining the wavelet band-pass filter with the Maximum Average Correlation Height algorithm is proposed, the Mexican Hat Maximum Average Correlation Height filter is designed. The scale distortion or rotation distortion tolerance of a single filter in the VLC is expanded.Third, the method of combining the Sobel edge detector with the Maximum Average Correlation Height algorithm is proposed, the performance of the Maximum Average Correlation Height filter is improved. The scale distortion or rotation distortion tolerance of a single filter in the VLC is further expanded. Combining the Sobel edge detector, the Maximum Average Correlation Height reference template is designed. The scale invariant or rotation invariant recognition is achieved in JTC using the Maximum Average Correlation Height reference template.Finally, the method of combining the Gauss frequency domain low-pass filter with the Maximum Average Correlation Height algorithm is proposed, the Gauss Maximum Average Correlation Height filter is designed. The recognition of Hybrid distortion target (existing the scale distortion and rotation distortion simultaneously) in VLC is achieved by a single filter.In this paper, the designed filters are completed the computer simulation experiment, the designed Maximum Average Correlation Height reference template is completed the optical recognition experiment. The experimental results show that the scale distortion tolerance of the optimized Maximum Average Correlation Height filter in VLC is0.76～1.36times, the rotation distortion tolerance is-15～20degrees. The scale distortion tolerance of the designed Mexican Hat Maximum Average Correlation Height filter in VLC is0.79～1.46times, the rotation distortion tolerance is-35～35degrees. The scale distortion tolerance of the improved Maximum Average Correlation Height filter by Sobel edge detector is0.76～1.56times, the rotation distortion tolerance range is80degrees. The scale distortion tolerance of Maximum Average Correlation Height reference template in JTC is0.93～1.21times, the rotation distortion tolerance range is20degrees. The designed Gauss Maximum Average Correlation Height filter can recognize the hybrid distortion target with the VLC, the distortion tolerance is rotation-8～24degrees and scaling0.92～1.16times.