Fast non-local Lee filter for SAR image despeckling using directional projection

This paper combines the Lee filter with the non-local mean filter, and a new similarity measure is derived based on the statistics of speckle noise, which extended the non-local means from the additive noise to the multiplicative noise. Also directional projection is adopted to accelerate the process of similarity computation. The results show its effectiveness. Experimental results illustrate that the proposed method can effectively smooth the speckle while preserving the details with reduced complexity.