Abstract:A bidirectional enhanced diffusion filter image de-noising model is presented. The diffusion equation is firstly simplified and analyzed to establish bidirectional diffusion coefficient. Hence, the twoway process of smoothing and sharpening can be achieved by the model in the diffusion process, To further enhance the strength of the smoothing and sharpening, image enhancement is used to enhance the overall outline of the image using wavelet transform, thus weakening texture detail of the image. Then, the threshold will be designed and improved, and it will be automatically controlled by maximum image gray value and iterative times, which can retain the image edge and detail features. The proposed model is be simulated. The experimental result shows that the new model is ideal, and it can improve the performance of de-noising and the protection of edge. The texture detail information is satisfactory. The peak signal to noise ratio is promoted drastically. Therefore,the performance is better than classical algorithms.