Overview of Speckle Noise Suppression Methods in SAR Image Based on NLM

Due to the diffuse reflection of the ground in SAR image and its serious speckle noise, the technology of noise suppression is an important research content. In this paper, the technology of noise suppression and various improved methods based on non-local means (NLM) are introduced. Besides, the experimental comparison of each NLM filter method is carried out. Finally, the possible research directions of NLM in future are considered and discussed.