Image Enhancement using a Combined Approach of Spatial and Transformation Domain Techniques

Image enhancement is the task of applying certain alterations to an input image like as to obtain a more visually pleasing image. The alteration usually requires interpretation and feedback from a human evaluator of the output resulting image. Image enhancement is to improve the image quality so that the resultant image is better than the original image for a specific application or set of objectives. In this paper, there is a combined approach of gray level transformation algorithms, such as logarithmic transform and power law transform, with alpha rooting algorithm for contrast enhancement. Enhancement techniques such as alpha rooting operate on the transform domain where as grey level transformations operate on individual pixel. However, these techniques bring about tonal changes in the images and can also generate unwanted artifacts in many cases, as it is not possible to enhance all parts of the image in balanced manner. Keywords— Image enhancement, spatial domain technique, Transform domain technique, alpha rooting, power law transformation, logarithmic transformation.