Method and device for enhancing image contrast, display apparatus, and storage medium

A device for enhancing image contrast comprising:

• an image division unit configured to divide an input image into a plurality of input sub-images according to gray values of pixels of the input image, each of the plurality of input sub-images corresponding to a gray value distribution range, the gray value distribution ranges of the respective input sub-images being different from each other, and each input sub-image comprising all pixels, among the pixels of the input image, whose gray values are within the gray value distribution range of the input sub-image;
• an image equalization unit configured to perform an equalization processing on each of the plurality of input sub-images, and obtain a plurality of output sub-images corresponding to the plurality of input sub-images, respectively, based on a result of the equalization processing;
• an image merging unit configured to merge the plurality of output sub-images to obtain an output image corresponding to the input image, wherein the image division unit comprises:
• a histogram statistics subunit configured to perform a histogram statistics on the gray values of the pixels of the input image to obtain a histogram of the input image, wherein the histogram of the input image indicates a total gray value distribution range of the input image and comprises pixel information of the input image, and the pixel information of the input image comprises a plurality of gray values and the number of pixels of the input image corresponding to each of the plurality of gray values;
• and
• a sub-image division subunit configured to divide the input image into the plurality of input sub-images according to the histogram of the input image, wherein the subimage division subunit is configured to:
• divide the input image into n input sub-images respectively corresponding to different gray value distribution ranges according to the histogram of the input images, such that a total gray value of each input sub-image is the same, the total gray value of catch input sub-image is obtained by using the following formula (1):
• g=(1/n)G (1)
• wherein g is the total gray value of each input sub-image and is obtained by summing gray values of all pixels in the input sub-image, and G is a total gray value of the input image and is obtained by summing gray values of all pixels of the input image.