Fig. 1
Parallel-beam projection of two volume slabs. It shows a parallel-beam projection of the cubic volume in the centre on the detector plane on the right. Two slabs in the volume are outlined in black, and indicated by North-West (NW) diagonal patterns and North-East (NE) diagonal patterns. The projections of these two slabs are correspondingly patterned with NW respectively NE diagonals, and do not overlap