In traditional image analysis, an operator draws the regions of interest by hand on each section. This is slow, and the regions vary from one operator to the next, so they are hard to reproduce. With atlas registration:
- Every anatomical region is defined automatically by atlas boundaries
- ROIs are identical across all sections and all animals
- Hundreds of regions are available simultaneously (not only the few an operator would draw)
- Sub-regions can be merged or split programmatically for different analysis granularities