Abstract: In the light of contradiction of reducing speckle and effectively keeping details in speckle filtering for SAR images, this paper proposes a image denoising method of SAR（Synthetic Aperture Radar） image which is based on edge detection and four interpolation subdivision. The method firstly detects the edge of SAR image by canny operator, and then uses four interpolation subdivision to carry on image denoising and edge image denoising respectively. Then it carries on the reconstruction of the edges information in the edge region and gets a new denoising image. Finally, the experimental results are evaluated by two evaluation indexes including Equivalent Number of Looks（ENL） and Edge Save Index（ESI）. Experimental results show that the method proposed in this paper is a more effective method than classical method of image denoising and effectively realizes both denoising and edge preservation.

Key words: Synthetic Aperture Radar（SAR）, edge detection, canny operator, four interpolation subdivision, image denoising

摘要： 针对SAR图像相干斑滤波中存在的降低相干斑与有效保持细节信息这一矛盾，提出了一种基于四点插值细分的SAR图像去噪的新算法，将四点插值细分规则运用到图像去噪中，并与边缘检测相结合。先用canny算子提取图像边缘，进而通过四点插值细分方法分别对边缘图像和原始图像进行去噪，然后再对边缘信息进行边缘信息的重构，得到新的去噪图像。并通过等效视数、边缘保持指数等评价指标对去噪结果进行了评价。实验结果表明，与其他去噪方法相比，该算法在有效地去噪的同时，可有效地保留图像的边缘信息，具有较好的去噪结果。

关键词: 合成孔径雷达, 边缘检测, canny算子, 四点插值细分, 图像去噪