Principle objective of Image enhancement is to process an image so that
result is more suitable than original image for specific application. Digital
image enhancement techniques provide a multitude of choices for improving the
visual quality of images. Appropriate choice of such techniques is greatly
influenced by the imaging modality, task at hand and viewing conditions. This
paper will provide an overview of underlying concepts, along with algorithms
commonly used for image enhancement. The paper focuses on spatial domain
techniques for image enhancement, with particular reference to point processing
methods and histogram processing.