ABSTRACT

An edge-preserving filter that overcomes this limitation is the Kuwahara filter [Kuwahara et al. 76]. Based on local area flattening, the Kuwahara filter properly removes details even in a high-contrast region, and protects shape boundaries even in low-contrast regions. Hence it helps to maintain a roughly uniform level of abstraction across the image, while providing an overall painting-style look. Unfortunately the Kuwahara filter is unstable in the presence of noise and suffers from block artifacts. Several extensions and modifications have been proposed to improve the original Kuwahara filter. A discussion can be found in [Papari et al. 07].