空间平移不变和角度受限下转动不变的特征识别与滤波器的设计

徐原能等人曾提出借助于circular harmonic expansion(圆谐波展开),设计空间平移不变和转动不变的滤波器系统,用于特征识别。本文在他们的基础上提出一种实现空间平移不变和在一定的角度范围内转动不变的特征识别方法,给出相应的滤波器设计具体公式。虽然转动不变的角度范围受到限制,但能够提高系统的信噪比,同时,不需要通过测量靶与待识别图象之间的相关函数的相位因子,来判定转动角度,而是代之直接测量相关函数的绝对值,由此推算转动角度。本文还列举一个具体的例子,来演示滤波器的设计方法,并与徐原能方案 关键词：

SPACE-INVARIANT AND ROTATION-INVARIANT IN A GIVEN ANGLE RANGE PATTERN RECOGNITION AND THEIR FILTER DESIGN

Hsu et al have proposed a method of filter design for space-invariant and rotation-invariant digital pattern recognition in terms of circular harmonic expansion. Based on their method, we suggest a new filter design for space-invariant and rotation-invariant in a given angle range pattern recognition system. Although rotation-invariant angle is restricted to centain extents, the ratio of signal to noise might be increased, meanwhile we need not measure the phase factor of correlation function between target and recognition image in order to determine the rotation angle instead of directly measuring the absolute value of correlation function. We also give one simple example to demonstrate this design and compare it withthat suggested by Hsu et al.