This paper presented a image de-noising algorithm based on dictionary learning.It implemented dictionary learning by substituting error restriction for non-zero number restriction on the base of K-SVD method.By analyzing effection on peak signal-to-noise ratio of denoising by different nonzeros number,it proposed implementing dictionary learning by using different number non-zero respectively for low-noise image and high-noise image to obtain sparsity represetation of image and restore original image.The re...