We propose a novel hashing scheme for image retrieval,
clustering and automatic object discovery. Unlike commonly
used bag-of-words approaches, the spatial extent of
image features is exploited in our method. The geometric
information is used both to construct repeatable hash keys
and to increase the discriminability of the description. Each
hash key combines visual appearance (visual words) with
semi-local geometric information.
Compared with the state-of-the-art min-Hash, the proposed
method has both higher recall (probability of collision
for hashes on the same object) and lower false positive
rates (random collisions). The advantages of Geometric
min-Hashing approach are most pronounced in the presence
of viewpoint and scale change, significant occlusion
or small physical overlap of the viewing fields. We demonstrate
the power of the proposed method on small object
discovery in a large unordered collection of images and on
a large scale image clustering problem