Meaningful Matches in Stereovision

Neus Sabater (1) , Andrés Almansa (2) , Jean-Michel Morel (1)

1 CMLA - Centre de Mathématiques et de Leurs Applications
2 LTCI - Laboratoire Traitement et Communication de l'Information

This paper introduces a statistical method to decide whether two blocks in a pair of of images match reliably. The method ensures that the selected block matches are unlikely to have occurred "just by chance.'' The new approach is based on the definition of a simple but faithful statistical "background model" for image blocks learned from the image itself. A theorem guarantees that under this model not more than a fixed number of wrong matches occurs (on average) for the whole image. This fixed number (the number of false alarms) is the only method parameter. Furthermore, the number of false alarms associated with each match measures its reliability. This "a contrario" block-matching method, however, cannot rule out false matches due to the presence of periodic objects in the images. But it is successfully complemented by a parameterless "self-similarity threshold." Experimental evidence shows that the proposed method also detects occlusions and incoherent motions due to vehicles and pedestrians in non simultaneous stereo.

Mots clés: Stereo; block-matching; Number of False Alarms (NFA); a contrario detection

Domaines: Vision par ordinateur et reconnaissance de formes [cs.CV]

Neus Sabater, Andrés Almansa, Jean-Michel Morel. Meaningful Matches in Stereovision. IEEE Transactions on Pattern Analysis and Machine Intelligence, 2012, 34 (5), pp.930-942. ⟨10.1109/TPAMI.2011.207⟩. ⟨hal-00647995⟩