Figure 2. Voxel based coregistration. If the voxel values from exactly registered pairs of identical images are plotted against each other, a straight line is produced, as shown in (a). In (b), one image has been translated in the Y direction by a single voxel and the scattergram now has a characteristic pattern. Voxel based coregistration algorithms work to minimize the spread of this distribution. The images shown here were produced using ANALYZE AVW version 3.1 [5].