| approx_chain1 | Approximate a closed chain code by arcs and lines. |
| approx_chain2 | Approximate a closed chain code by arcs and lines. |
| fetch_chain | Contour of an object as chain code. |
| fetch_contour | Access the contour of an object. |
| fetch_polygon | Polygon approximation of a region. |
| split_skeleton2 | Split lines represented by one pixel wide, non-branching regions. |