In this paper, an overlapped sub-block gray-level average method for contrast enhancement is presented. The digital
image correction of uneven illumination under microscope transmittance is a problem in image processing, also sometimes
the image in the dark place need to correct the uneven problem. A new correction method was proposed based on the mask
method and sub-blocks gray-level average method because Traditional mask method and background fitting method are
restricted due to application scenarios, and the corrected image brightness is low by using background fitting method, so
it has some limitations of the application.
In this paper, we introduce a new method called AOSCE for image contrast enhancement. The image is divided into
many sub-blocks which are overlapped, calculate the average gray-level of the whole image as M and the calculate the
average gray-level of each one as mi, next for each block it can get d = mi - m, each block minus d to get a new image,
and then get the minimum gray-level of each block into a matrix DD to get the background, and use bilinearity to get the
same scale of the image. over fitting the image in matlab in order to get smoother image, then minus the background to
get the contrast enhancement image.