Range Limited Quad-Histogram Equalization Method for Image Contrast Enhancement

Histogram equalization is a very popular technique for image contrast enhancement. Histogram equalization defines the clarity of picture and sometime improves brightness. But sometime it is not very good for consumer electronics, because of preserving the original brightness. Range limited bi-histogram equalization RLBHE applied for consumer electronics. This paper proposes novel extension of RLBHE referred to as range limited quad-histogram equalization RLQHE. This method is applied as first it divides the input histogram into two sub-images by a threshold. Then again two sub-images divide in to two sub-images by using another threshold that minimizes intra- class variance. All these sub-images separate the object from background. Then, Range means it calculate the minimum absolute mean brightness error between actual image and equalized image. The result shows that proposed method is better than previous method for image contrast enhancement. Proposed method preserves original brightness as actual image. It is very well suited for consumer electronics product