Low Contrast Color Image Enhancement by Using GLCE with Contrast Stretching

International Journal of Research and Scientific Innovation (IJRSI) | Volume V, Issue II, February 2018 | ISSN 2321–2705

Low Contrast Color Image Enhancement by Using GLCE with Contrast Stretching

Sarla Gautam¹, Prof. Tripti Saxena², Prof. Vijay Trivedi³

¹M.Tech Scholar, LNCT, Bhopal, Madhya Pradesh, India
^{2, 3} Assistant Professor, LNCT, Bhopal, Madhya Pradesh, India

Abstract— The principal objective of enhancement techniques is to process an image so that the result is more suitable than the original image for a specific application. Image enhancement techniques used in many areas such that Forensics, Astrophotography, Fingerprint matching etc. In image processing, low contrast image analysis is a challenging problem. Low contrast digital images reduce the ability of observer in analyzing the image. Here we propose a new method for low contrast color images enhancement. This method uses two step processing, in first step global contrast stretching method is applied to improve the contrast of image and then in second step global and local contrast enhancement(GLCE) is performed because applying the local contrast enhancement along with global contrast enhancement is much better than that of global contrast enhancement only or local contrast enhancement only. To evaluate the effectiveness of our method we choose two widely used metrics Absolute Mean Brightness Error (AMBE) and PSNR. Based on results of these two metrics this algorithm is proved as a flexible and effective way for low contrast image enhancement.

Index Terms—Contrast, GLCE, Image Enhancement

I. INTRODUCTION

Image enhancement is a process of improving the quality of image by improving its feature. Image enhancement is a method of digital image processing which processes the digital image. Image enhancement includes contrast and edge enhancement, feature sharpening and noise filtering and so on. Among these technique contrast enhancement is important because human eyes are more sensitive to the luminance than to the chrominance/color component of an image. Principle of Contrast enhancement is to improve the visual appearance of the image without introducing unwanted effects and artefacts. Various images like medical images, aerial images, satellite images and even real life photographs may suffer from noise and poor contrast due to the inappropriate lighting during image acquisition and/or wrong setting of aperture size and shutter speed of a camera, so it is necessary to enhance the contrast and remove the noise to increase image quality. Application area of image enhancement ranges from medical images to real life photography. Contrast enhancement is one of the challenging and interesting areas of image processing [1].

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