IMAGE CONTRAST ENHANCEMENT USING RECURSIVE DIVISION BASED HISTOGRAM EQUALIZATION

Abstract

Today, Images are most elaborative form of information. Images used in every field of engineering and science. Ex. NASA images, Satellite Images, Medical Science, Manufacturing industry quality control images. Whenever image is taken by Satellite or By the medical photography for medical purpose, it has noise and poor quality in form of brightness, contrasts, blurred, etc. because of poor quality of light and noise between the camera lens and object. Hence before analysing the image, it needs to be enhanced. Enhancement depend on the type of artifact in image and the purpose for which image will be used or type of information we want from image. Images taken by satellite or by camera in poor light has poor contrasts quality. Hence objects in image have not visible properly. To increase the contrasts of the image we use Histogram Equalization technique. In the proposed algorithm image is divided into sub-images using histogram and histogram equalization take place on each sub-segment independently. Then join the segment to produce final image. Sometime our method loss natural appearance, to gain the natural appearance Image Normalization concept is used. And to segment the image into sub-segment used a threshold intensity value is used. This value has many selection criteria like median mean, otsu ant many other strategy too.