Non-linear transform algorithm for image contrast enhancement
Jinshan Wang · Guangdian gongcheng · 2006
Contrast type of original image is determined by a new criterion. Gray transform parameters are directly obtained by the new criterion. Global enhancement is implemented to the original image. After making discrete stationary wavelet transform to the enhanced image, details enhancement is done by certain nonlinear operator in the high frequency sub-bands of each decomposition level respectively. Experimental results show that the new algorithm can enhance the global contrast of image effectively; meanwhile it also emphasizes the detail information of the target in the image well.