الملخص

Modern digital camera technology has produced huge services for the users from different ages and specifications .It made it easer to have images, but the user still needs to enhance those images, which have some problems when taken by the camera, for not applying enough light, as taking it in cloudy weather or on bright light or dark area or taking it from a far distance, all these reasons make the picture not clear having ambiguous details and colors. So, through this research we used some image contrast enhancement techniques to adjust the light for dark images, to make them have deep detail, sharp edges and better quality. Contrast problem is one of the most problems that face those who work on research field or normal users.             The aim of this research is to improve the contrast of images that have bad contrast using both classical techniques and intelligence techniques. Among intelligence techniques we chose the fuzzy logic methods, to have images contain better colors all over the image and make the images look brighter. By studying the classical and fuzzy logic methods, we proposed a method named (Fuzzy Hyperbolic Threshold), the proposed method gave very good results. We applied the methods on gray, colored images and on a video, and used (Matlab 7) to implement those methods.