Comparison of gradient operator based pseudocolored enhanced medical images

In this paper pseudocoloring is taken as the tool for enhancing the gray medical images. Medical images like X-ray, CT scan, MRI and Ultrasound images are generally gray images. Human beings can only discern a few dozen gray level values while they can distinguish thousands of colors, the use of color for human interpretation could only improve the diagnosis process. This paper develops a number of nonlinear pseudocolor coding methods based on various gradients operators values. Firstly, we get the gradient image and we define two thresholds to delimit the different extents according to gray values. We used some techniques for the comparison like Roberts´s operator technique, Four neighbours operator technique, Sobel operator technique, Prewitt operator technique and Canny operator technique. Then the pseudocoloring is carried out with nonlinear sine transforms after that they are compared with one another so as to get better results. Due to the choice of three parameters k1, k2 and k3 in the mapping functions, this method adds the flexibility. It can make the outline of the medical images clearer and effectively highlight the disease areas, so the results improve doctor´s diagnosis.