A NONLINEAR METHOD FOR EDGE DETECTION OF LOW SNR IMAGE
低信噪比图象边缘提取的非线性方法

A nonlinear method for detecting the edge of low-SNR image is developed. This method adopts the filtering in large window to smooth the noise and the nonlinear diffe-rential operator in small window to detect the edges. A criterion of noise-guided threshold selection is introduced to segment the derivative image so that the threshold can be determined automatically. In large window's filtering, the technique of 2-D convolution implementation by two 1-D convolutions in series is taken to reduce the storage space of the filter. Finally, the performance of this method is evaluated, and experimental results are given.