Geometric Hashing
Geometric hashing encodes a set of geometric feature points into an invariant hash for point pattern matching and object recognition, invariant to translation and rotation.
Purpose
Fast point-set matching in computer vision, invariant under rigid transforms (translation, rotation, scaling).
Mechanism
A pair of points is chosen as a basis; the remaining points are encoded in the basis coordinate system into a hash table (quantized coordinates). At query time, basis pairs are tried on the unknown point set and matched via table lookup.
Use cases
- Object recognition
- Point cloud registration
- Molecular structure matching