Primitive-based contrast enhancement method

In this article we present a new solution for the problem of contrast enhancement. The method is based on the decomposition of the original image into its primitive components. In a first stage a multiresolution representation of the image is computed yielding transform coefficients proportional to the maximum of the local gradient at a specific scale and at a specific position in the image. As an image detail exists at several scales, the transform coefficients corresponding to the same image primitive are grouped. Contrast is enhanced by groupwise non-linear amplification of the transform coefficients. An inverse transform is then applied to the modified coefficients, resulting in a uniformly contrast-enhanced image without artifacts. Preliminary results demonstrate the effectiveness of this method. It could be used in a wide range of applications.