Figure 2.

Illustration of matched filtering. A binary ‘matched filter template’ (left) is multiplied point wise across the image volume (center) to obtain the matched filter values (right). The matched filter value space is the same size as the image volume, while the template is smaller. Matched filter values are recorded at the center voxel of the template. Note that the edges of the matched filter value space are not populated due the template hitting the boundary of the image space.