Contrast enhancement for grayscale images

Introduction

A grayscale image captures the intensity of light in pixels. In digital image processing, intensity values are discrete integers ranging from 0 as the lowest intensity or darkest, to 255 as the highest intensity or brightest. As opposed to RGB images with numerous color variations, disparity between darkness and brightness or namely contrast is the only distinguishing factor among pixels for grayscale images. Hence it is vital to have a good contrast to accurately capture information and better visualize features.

In this blog, we will deal with an example where contrast is low. We will then define histogram to measure and use a few techniques to enhance contrast. While aiming to capture edges as image feature, we will demonstrate the impact an image with a good contrast has on this process. Continue reading