基于梯度的边缘检测算法，主要是针对阶跃形边缘的检测。Morrone等人提出的基于局部能量和相位一致性的边缘检测方法，则同时适用于阶跃形和屋脊形两类边缘的检测。根据等Q分解原则设计了一组基于Hilbert变换的正交滤波器对，并根据广义相位理论提取滤波后的局部能量和相位信息，在分析了噪声影响和展频处理后，通过计算相位一致性检测图像中的边缘。由于基于相位一致性的边缘检测具有不受光照条件影响，无需计算局部能量极值的特点，因此，在边缘检测的准确率与定位精度上，取得了较好的试验效果。

Gradient based edge detection methods are mainly focus on step edges. However local energy based edge detection methods and phase congruency based edge detection methods are effective both to step and peak edges. According to the characters of mammals visual cortex, this paper designs a group of quadrature filters by Hilbert transforms, by which the local energy and phase congruency are calculated. After noise analyzing and frequency distribution analyzing, edges are detected according to phase congruency value. As phase congruency based edge detection method is insensitive to variations in image illumination, and it makes looking for the maxima in local energy become unnecessary, we get good experimental result on the location and accuracy of edge detection.