Features
The detection and description of local image features can help in object recognition. The SIFT features are local and based on the appearance of the object at particular interest points, and are invariant to image scale and rotation. They are also robust to changes in illumination, noise, and minor changes in viewpoint. In addition to these properties, they are highly distinctive, relatively easy to extract and allow for correct object identification with low probability of mismatch. They are relatively easy to match against a (large) database of local features but however the high dimensionality can be an issue, and generally probabilistic algorithms such as k-d trees with best bin first search are used. Object description by set of SIFT features is also robust to partial occlusion; as few as 3 SIFT features from an object are enough to compute its location and pose. Recognition can be performed in close-to-real time, at least for small databases and on modern computer hardware.
Read more about this topic: Scale-invariant Feature Transform
Famous quotes containing the word features:
“All visible objects, man, are but as pasteboard masks. But in each event—in the living act, the undoubted deed—there, some unknown but still reasoning thing puts forth the mouldings of its features from behind the unreasoning mask. If man will strike, strike through the mask!”
—Herman Melville (1819–1891)
“The features of our face are hardly more than gestures which force of habit made permanent. Nature, like the destruction of Pompeii, like the metamorphosis of a nymph into a tree, has arrested us in an accustomed movement.”
—Marcel Proust (1871–1922)
“However much we may differ in the choice of the measures which should guide the administration of the government, there can be but little doubt in the minds of those who are really friendly to the republican features of our system that one of its most important securities consists in the separation of the legislative and executive powers at the same time that each is acknowledged to be supreme, in the will of the people constitutionally expressed.”
—Andrew Jackson (1767–1845)