COMPUTER GRAPHICS forum Speed-up Technique for a Local Automatic Colour Equalization Model

In this paper we propose a speed-up technique for a local automatic colour eqrtalization operaror derived from a model of the human vision System. This method is characterized by local und globalfiltering effects, that simrrltaneously achieve different equalization rasks e.g. peSonning colour and lightness constancy, realizing dynamic image data driven srretching, controlling the contrast. We describe a way to quickly create a filtering mapping function to peSorm the global component of the mapping. This method is based on singular value decomposition (SVD) applied to sampled andfiltered points in the input image. Then, the local information is added computing the basic algorithrn on a neighbourhood of euch inputpixel. A slight quality loss is the price that we have to pay for a speed-up of more than two orders of magnitude of the basic algorithrn. We present the resrrlts on several images and discuss the efiiciency and the drawbacks of rhe speed-up technique