Multi-channel Mutual Information Using Scale Space

We propose a new voxel similarity measure which utilises local image structure and intensity information. Gaussian scale space derivatives provide the structural information. Each derivative is assigned an information channel of N-D normalised mutual information. We illustrate the behaviour of the measure for a simulated signal and 2D medical brain images and demonstrate its potential for non-rigid, inter-subject registration of 3D thorax MR images as a proof of concept.