A FAST FILTERING ALGORITHM FOR IMAGE-ENHANCEMENT

In this paper, a filtering algorithm for fast image enhancement is des cribed. The algorithm tries to make the minimum modification on the or iginal image structures while it performs noise smoothing at a given f iltering level. The filtered image is a weighted combination of four s ubimages obtained from low-pass filtering the original image along fou r major directions. The weighting on each subimage is controlled by th e differences between these subimages and the original image. The resu lting image is then nonsymmetrically sharpened to enhance the image st ructure boundaries. The overall effect of this filtering structure is effective adaptive noise reduction and edge enhancement with an effici ent implementation using array processors. The high regularity and par allelism of the algorithm also makes it suitable for its efficient imp lementation using very large scale integrated (VLSI) circuits or multi processor systems. The performance of the algorithm in effectively red ucing image noise and preserving/enhancing important image structures is discussed and demonstrated using several MR images from a low-field -strength MR imaging system.