基于噪音谱分析的新型指数空间匹配滤波器设计

光学相关识别过程中,为减小输入场景中背景噪音对输出相关点的影响,通过分析背景噪音和目标图像的傅里叶谱,在匹配滤波函数中引入一由背景噪音傅里叶谱确定的指数函数,通过指数函数对匹配滤波函数振幅进行非线性调制,使设计的指数型空间匹配滤波器对背景噪音谱透过率小于目标图像谱透过率,从而增加输出相关平面上的信噪比,以实现相关点的正确探测。模拟结果表明当参量m由0增加到1.2时,相关峰值下降2.28倍,信噪比增加3倍。模拟和实验结果均表明:与纯相位匹配滤波器相比其抗噪能力得到明显改善。

Design of exponent type space matched filter based on analysis of background noise Fourier spectrum

In order to limit the influence of background noise on correlation spot on the output correlation plane,the Fourier spectrum of the matched filter function and the background noise were compared,and the amplitude of the matched filter was nonlinearly modulated based on the exponent function relying on the Fourier spectrum of the background noise.It enables the filter to reduce the transmittance in the area of the intense noise Fourier spectrum relative to the transmittance for input image Fourier spectrum.The signal-to-noise ratio on the output correlation plane was improved and the detection of the correlation spots was realized.The results of computer simulation show that the correlation peak value reduces 2.28 times and the signal-to-noise ratio increases 3 times when m changes into 1.2 from 0.The results of simulation and experiment show that the anti-noise capability of exponent type space matched filter is imprved obviously.