一种改进的SAR影像边缘检测方法

由于SAR影像具有乘性相干斑噪声，某些对光学影像有较好检测性能的边缘检测算子，对于SAR影像并不适用，因此本文提出了一种将改进后的Ratio算子与Canny算子相组合的新方法。首先采用多种客观评价指标，得出经典方法中的Lee滤波能有效去除噪声，且最大限度保留了梯度信息，适用于边缘检测；然后对边缘检测具有恒虚警特性的Ratio算子进行改进，改进后的算子更利于影像归一化处理；最后利用改进后的Ratio算子与Canny算子组合成新方法。试验结果证明，组合后的新方法显著提高了边缘检测正确率和定位精度，改善了边缘连续性，具有一定的有效性和实用性。

An Improved Edge Detection Algorithm for SAR Images

For the SAR image with multiplicative noise, some edge detectors in optical image effectively does not apply in the SAR image.An improved edge detection algorithm for SAR image is presented.Three steps are involved.Firstly, a variety of evaluation index are used, which concluded that Lee filter can effectively remove the noise, and retain the gradient information to the maximum extent, suitable for SAR edge detection.And then put forward an improved Ratio detector, which is more conducive to image normalization.Finally, propose a new edge detector which combined the improved Ratio detector and Canny detector.The results indicate that new algorithm has a good performance in the edge detection and positioning accuracy, improves the edge continuity.