Contrast enhancement of sports images using modified sigmoid mapping function

Current video and image systems are typically of limited use in poor visibility conditions such as in poor illumination, rain, fog, smoke, and haze. These conditions severely limit the range and effectiveness of imaging systems because of the severe reduction in contrast. The contrast of any image is a very important characteristic which decides the quality of image. Our chief goal in this paper is to develop a contrast enhancement technique to recover a sports image shot with poor illumination to improve its quality. In our method contrast enhancement is done based on a modified sigmoid mapping function. Several methods are proposed for gray scale images wherein while dealing with color images the procedure becomes complicated. In this method processing is done on RGB color planes and the results are found to be satisfactory. We provide simulation results of our technique applied to real images, which are hard to be contrasted by other conventional techniques.