Contrast Enhancement and Brightness Preservation of Radiography Images using Gamma Correction

In this Research paper, the purpose of Image enhancement is to process an image so that result is more suitable than original image for particular application. Digital image enhancement techniques provide a multitude of choices for improving the visual quality of images. Appropriate variety of such techniques is greatly influenced by the imaging modality, undertaking at hand and viewing situation. This paper will provide an overview of underlying concepts, along with algorithms normally used for image enhancement. An image can have low contrast or undesirable quality due to a number of reasons like reduced quality of imaging device, unfavorable external conditions at the time of image preprocessing and many more. Image enhancement is used to improve the usual effects and clarity of image or to make the original image more favorable for computer to process. In proposed method, full image has been divided into two parts in low contrast and high contrast on the basis of their threshold value. We have applied large gamma values only on low contrast image using gamma correction which will be more informative. With the help of merging we get the resultant radiography image. The results will be compared on the basis of histograms, mean, standard deviation, variance and average gradient values and compared with existed gamma correction techniques using matlab