7-4 Improvement of the grouplet transform for its application to color-image denoising

Abstract

Previously we have proposed the color-image denoising method that applies the tight-frame grouplet transform to shift-invariant Haar wavelet coefficients of a noisy color image and then denoises those grouplet coefficients with the hard color-shrinkage. This method preserves textures and diagonal edges much better than the conventional denoising method, but it tends to cause color smears. To solve this problem, we present a method to control the application of the grouplet transform.