In order to preserve the edges and details of the image better,a modified block-matching and 3D filtering algorithm based on the directed diffusion is proposed.First,the block-matching and 3D filtering result is divided into three perpendicular subbands by using the wavelet decomposition.Second,by adding the diffusion operator and diffusion coefficients to the directed diffusion equation,the diffusion speed can be accelerated and edges can not be blurred quickly.Then we diffuse the subband of the high-frequ...