Adaptive median filter algorithm to remove impulse noise in x-ray and CT images and speckle in ultrasound images

摘要

An adaptive median filter algorithm to remove impulse noise in x-ray images and speckle in ultrasound images is presented. The ordinary median filter tends to distort or lose fine details in an image. Also, a significant amount of the original information in the image is altered. The proposed algorithm considers the local variability over the entire image to ensure that the fine details are preserved and more than 90 percent of the original information is retained. The robustness of the algorithm is demonstrated by applying it to images from different modalities like diagnostic x-ray, CT, portal imaging and ultrasound.