Enhanced dynamic quadrant histogram equalization plateau limit for image contrast enhancement

摘要

Consumer electronic devices require brightness preservation while image enhancement. Many of the histogram equalization techniques that have been introduced tend to strike out the mean image brightness while the process of enhancement is carried out. Hence, we suggest a method that enhances the image while keeping its brightness in a better form as compared to the former methods applied. Firstly, based on median value, the input image histogram is divided into sub-histogram and this process reprises until we have derived 8 sub-histograms. Further, the clipping of the histogram is implemented based on the average pixels in each sub-histogram. Then, each sub-histogram is assigned with a new dynamic range and finally customary histogram equalization is done independently on each sub-histogram. Proposed method is tested against conventional methods and results indicate that image mean brightness is preserved better than other methods while enhancing the image. The proposed method keep the brightness save of the original image while during the enhancement of the images. Many images has been taken from the SIPI database and applied the proposed method for the contrast enhancement of the low contrast images and results are improved. The major problem is to keep the brightness of the low contrast image preserve. The proposed technique has dealt with brightness preservation of the images.