On Current Contrast Enhancement Techniques for Remote Sensing Images

Input images that are captured by remote sensing devices are sometimes not really in good brightness and con-trast. Therefore, a process known as a digital image contrast enhancement is normally required to increase the quality of these low Contrast images. Histogram Equalization (HE) has been an essential addition to the Image Enhancement world and other Enhancement techniques like Classical Histogram Equalization(CHE),Adaptive Histogram Equalization (AHE), BiHistogram Equalization (BHE) and Recursive Mean Separate Histogram Equalization (RMSHE) methods enhance contrast of remote sensing images but brightness is not well preserved, which gives an unpleasant look to the final image obtained. hence improvement in these old techniques are done by various researchers in the world. This paper contain a survey of all the current techniques used to enhance contrast of remote sensing images with results, advantages and disadvantages of these techniques.