denoising medical images using calculus of variations

we propose a method for medical image denoising using calculus of variations and local variance estimation by shaped windows. this method reduces any additive noise and preserves small patterns and edges of images. a pyramid structure-texture decomposition of images is used to separate noise and texture components based on local variance measures. the experimental results show that the proposed method has visual improvement as well as a better snr,rmse and psnr than common medical imgae denoising methods.  experimental results in mr denoising show that snr,psnr and rmse have been improved by 19,9 and 21 percents respectively.