A simple approach for image enhancement using new power-law transformation operators

In this paper, we present a new approach for the enhancement of a highly underexposed color image using a power-law transformation operator. A function called exposure [1] is used to measure the intensity exposition of the image. This function facilitates the estimation of highly underexposed region of the given image. The chromatic information of the color space is decoupled from the achromatic information using HSV (Hue, Saturation and Intensity) model. The hue component, in the model is preserved to keep the original color composition of the image intact. The other two components of the model are saturation and intensity. These two components play a significant role in enhancement of highly underexposed images by recovering the lost information in the image. New power-law transformation operators are defined for the two components, i.e. saturation and intensity, to improve the tone of the image. The values of these two components are varied to get the enhanced image.