Figure 2.

Incremental alignment of serial section images. The original section images (top row) are unaligned. After applying the appropriate transformation (T_i) to section i, the resulting transformed image is in alignment with the original image of section i–1. Likewise, the transformed section i+1 is in alignment with the untransformed section i. Since each alignment is independent of alignments between other sections, incremental alignments allow easy modification of alignments. Ultimately, the incremental alignment is converted to an absolute alignment for analysis.