SIFT Introduction
The SIFT algorithm is a powerful algorithm to extract information from a real-world image. SIFT - Scale-Invariant Feature Transform - can, given the image, identify key feature points on the image and provide a discription for each such point. The description can be saved to a file in a compact format. Later, this description can be compared against with descriptions from other images and questions such as "Are the two images similar?" can be answered. The SIFT algorithm provides the following key advantages over similar algorithms:
- The Keypoints thus obtained are Scale/Rotation/Illumination invariant.
- The keypoint locations are more precise and repeatable, because SIFT uses subpixel localization and multiple scale keypoint identification.