Selecting features from image data

摘要

SIFT features are selected from an input image. A SIFT procedure is applied to the input image to obtain candidate keypoints. For each candidate keypoint, there is calculation of a first Laplacian value (Lu) for pixels in an upper Scale Space and a second Laplacian value (Ll) for pixels in a lower Scale Space, based on the position of the candidate keypoint. A candidate keypoint is discarded if a Laplacian value Lc of the keypoint position is less than or equal to either of Lu or Ll. In the case that the candidate keypoint is not discarded, the candidate keypoint's Laplacian strength (Ls) is calculated, based on a relative change in Laplacian value from Lc to Lu and from Lc to Ll. One or more candidate keypoints are selected as SIFT features based on the corresponding Laplacian strength.

主权项

1. A method for selecting SIFT features from an input image, the method comprising:
applying a SIFT procedure to the input image to obtain candidate keypoints; calculating, for each candidate keypoint, a first Laplacian value (Lu) for pixels in an upper Scale Space and a second Laplacian value (Ll) for pixels in a lower Scale Space, based on the position of the candidate keypoint; discarding a candidate keypoint if a Laplacian value Lc of the keypoint position is less than or equal to either of Lu or Ll; calculating, in the case that the candidate keypoint is not discarded, the candidate keypoint's Laplacian strength (Ls) based on a relative change in Laplacian value from Lc to Lu and from Lc to Ll; and selecting one or more candidate keypoints as SIFT features based on the corresponding Laplacian strength.