New adaptive image contrast enhancement method
Tian-Hu Yu, Sanjit K. Mitra · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1993
In direct methods of contrast enhancement, a contrast measure is first defined, which is then modified by a mapping function to generate the pixel value of the enhanced image. Various mapping functions such as the square root function, the exponential function, etc., have been introduced for the contrast measure modification. However, these functions do not produce satisfactory contrast enhancement results and are usually sensitive to noise and digitization effects. In addition, they are computationally complex from the point of view of implementation. In this paper, we propose a simple polynomial mapping function for the contrast measure modification. The polynomial function is ready to implement on digital computers and provides very satisfactory contrast enhancement. We also introduce an adaptive clipping technique to control the dynamic range of the output image.