  There are several images that do not have uniform brightness which pose a
challenging problem for image enhancement systems. As histogram equalization
has been successfully used to correct for uniform brightness problems, a
histogram equalization method that utilizes human visual system based
thresholding(human vision thresholding) as well as logarithmic processing
techniques were introduced later . But these methods are not good for
preserving the local content of the image which is a major factor for various
images like medical and aerial images. Therefore new method is proposed here.
This method is referred as "Human vision thresholding with enhancement
technique for dark blurred images for local content preservation". It uses
human vision thresholding together with an existing enhancement method for dark
blurred images. Furthermore a comparative study with another method for local
content preservation is done which is further extended to make it suitable for
contrast improvement. Experimental results shows that the proposed methods
outperforms the former existing methods in preserving the local content for
standard images, medical and aerial images.
