Multiscale color image enhancement

Abstract

Abstract This paper introduces a multiscale technique to improve the visual appearance of color images. The saturation and luminance components of a color image often contain complementary information. Details of an image that have low luminance contrast are sometimes distinguished from their background by their color saturation. Therefore, color image contrast can be enhanced by modulating the luminance component with the variations in the saturation component. Images generally contain details of many different sizes. In the present method the luminance and saturation components of a color image are separately decomposed into contrast primitives of different spatial scales. A new set of multiscale luminance contrast primitives is then constructed by modulating the original luminance primitives at every location in the image and at every spatial scale by the corresponding saturation contrast primitives. Reconstruction of the color image from the resulting set of multiscale primitives provides a representation of the original image in which local luminance contrast is clearly enhanced at all levels of resolution. The perceptual quality of the contrast enhanced color image is further improved by the application of a color saturation algorithm.