分析了使用VLC进行光学相关识别时目标图像长宽比的变化对匹配滤波器畸变容限和输出相关峰值的影响。利用非约束纯相位匹配滤波器算法和迂回相位编码方法设计匹配滤波器，对具有确定面积和透过率而长宽比不同的矩形目标进行光学相关识别。模拟和实验结果表明：随着目标图像长宽比增加，匹配滤波器畸变容限减小，相关峰值降低。VLC更容易识别长宽比趋近1的目标图像。

The effect of the aspect ratio change of target images on the distortion tolerance of matched filter and output correlation peak value is analyzed when VLC is used for the optical correlation recognition according to the diffraction theory. The matched filter was designed with the algorithm for the unconstrained phase-matched-only filter and the method of the detour phase coding. The optical correlation recognition was carried out to the rectangular targets whose area and transmissivity are fixed but the length-width ratio is different. The simulated and tested results show that the image symmetry becomes better,the distortion tolerance of matched filter and the correlation peak value are decreased with the increase of the aspect ratio of the target image,and VLC is easier to recognize the target image whose aspect ratio approaches to 1.