Combined forward and reverse correlation
Assignee3M Innovative Properties Company
InventorJanos Rohaly
Life of this patent
Estimating the term…
Abstract
Improved correlation techniques employ data from forward (template-to-reference) and reverse (reference-to-template) correlation to identify valid correlation peaks, enforce symmetry in correlation peaks, and/or combine forward and reverse correlation data. In embodiments, these techniques eliminate or reduce rms noise in a recovered signal peak location by enforcing correlation peak symmetry. The forward and reverse correlation methods described herein may be used for validation of correlation peaks, detection of outlier data points and improved interpolation, such as for higher accuracy localization of a peak center with sub-pixel resolution.
Claims14
A method of making a correlation between a first image and a second image in an image processing algorithm, comprising:
- computing a first correlation using image data associated with the first image as a template and using image data associated with the second image as a search area;
- determining a first correlation peak from the first correlation, the first correlation peak representing an image disparity from the first image to the second image;
- computing a second correlation using image data associated the second image as a template and using image data associated with the first image as a search area;
- determining a second correlation peak from the second correlation, the second correlation peak representing an image disparity from the second image to the first image;
- and
- validating the first correlation peak by comparing the second correlation peak to a threshold value, the threshold value based upon the first correlation peak.
A system comprising:
- first computing means for computing a first correlation using image data associated with the first image as a template and using image data associated with the second image as a search area;
- second computing means for determining a first correlation peak from the first correlation, the first correlation peak representing an image disparity from the first image to the second image;
- third computing means for computing a second correlation using image data associated the second image as a template and using image data associated with the first image as a search area;
- fourth computing means for determining a second correlation peak from the second correlation, the second correlation peak representing an image disparity from the second image to the first image;
- and
- fifth computing means for validating the first correlation peak by comparing the second correlation peak to a threshold value, the threshold value based upon the first correlation peak.
Dependencies are inferred from the claim text.