Abstract: The current paper describes processing of liver images via histogram equalization,Wiener filtering and median filtering.The gray level transformation technique was used for gray adjustment of the images after the processing.The images are put together and an analytical comparison is carried out for quality evaluation.The innovative gray level transformation technology after median filtering yields exquisite images,with clear tissue structure and stronger layered effect in the interest area,and thus it is significant to clinical diagnosis.The technology can attain gray level normalization display without manual adjustment of the window breadth,which facilitates computerized automatic identification.