Coherence-enhancing diffusion of colour images

Many image processing problems require the enhancement of coherent ow-like structures. This can be accomplished in a natural way by combining anisotropic diiusion ltering and texture analysis by means of the structure tensor (second-moment matrix). In this paper an extension of these ideas to vector-valued images is presented. A structure tensor for vector-valued images is constructed as the sum of the structure tensors of each channel. This idea generalizes Di Zenzo's gradient for colour images by introducing an additional integration scale. The common structure tensor is used for steering the diiusion processes in each channel. The advantages of the lter are illustrated by applying it to an example.