Javidi B, Painchaud D
Appl Opt. 1996 Jan 10;35(2):318-31. doi: 10.1364/AO.35.000318.
The use of nonlinear techniques in the Fourier plane of pattern-recognition correlators can improve the correlators' performance in terms of discrimination against objects similar to the target object, correlation-peak sharpness, and correlation noise robustness. Additionally, filter designs have been proposed that provide the linear correlator with invariance properties with respect to input-signal distortions and rotations. We propose simple modifications to presently known distortion-invariant correlator filters that enable these filter designs to be used in a nonlinear correlator architecture. These Fourier-plane nonlinear filters can be implemented electronically, or they may be implemented optically with a nonlinear joint transform correlator. Extensive simulation results are presented that illustrate the performance enhancements that are gained by the unification of nonlinear techniques with these filter designs.
在模式识别相关器的傅里叶平面中使用非线性技术，可以在区分与目标物体相似的物体、相关峰锐度和相关噪声鲁棒性方面提高相关器的性能。此外，还提出了一些滤波器设计，使线性相关器具有针对输入信号失真和旋转的不变性。我们对目前已知的失真不变相关器滤波器提出了简单的修改，使这些滤波器设计能够用于非线性相关器架构。这些傅里叶平面非线性滤波器可以通过电子方式实现，也可以用非线性联合变换相关器以光学方式实现。文中给出了大量的仿真结果，说明了将非线性技术与这些滤波器设计相结合所获得的性能提升。
