Ultrasound Medical Image Denoising Based on Multi-direction Median Filter

In this paper, a method for removing ultrasound medical image noise is proposed. This method improves the original median filter by designing a suit of directional templates. In order to obtain local directions, a filter, which combines Gaussion blur with direction parameter, is designed. Then, directional templates based on local directions mentioned above are used as the filter for reducing spark noise. At last, the finial denoising result of each pixel is obtained from the filtered image or the original noise-polluted image by judging their differences. If the difference between two corresponding pixels of the two images is less than a threshold, the current pixel value of the noise-polluted image is kept. Otherwise, the one of the filtered image is used. The proposed method preserves the contour and the texture areas, which increases visual effects. Experiment results show the proposed method achieves sound performance on the synthetic images created by Field II.