Histogram Equalization Based Image Enhancement Techniques: A Comprehensive Study

Abstract

Digital images provide significant information. There are number of applications in which digital images are used.  While the image is transformed from one form to another, degradation of the image occurs. Numbers of techniques have been proposed by different researchers for the enhancement in the image quality, preserving its brightness and contrast. This paper gives a review on different techniques used for the image enhancement. For the enhancement of the image, histogram of the image is taken and equalization is performed. This paper reviews various schemes which have been used by researchers for the histogram equalization. The main focus of most of the techniques has been on reduction of variation in enhanced image from the actual image and maintaining the originality of the image. Brightness preserving schemes for example DSIHE and BBHE are few schemes that have been used by researchers for preserving the image contrast.