The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 16, 2003
Filed:
Jul. 30, 2001
Randall T. Crane, Fort Collins, CO (US);
Brian L. Hastings, Fort Collins, CO (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
Cross correlation between a reference image frame and a comparison image frame determine the direction of motion relative to x and y orthogonal axes for a pointing device that uses optical imaging to monitor movement relative to a surface. Pixel data for a portion of the surface are loaded into a buffer memory that shifts the data between successive positions in the buffer memory as each pixel of a comparison frame is processed to compute cross correlation. Auto correlation is determined for positions in the reference frame and used with the cross correlation results to determine a sub-pixel interpolation for the movement of the pointing device. A new reference frame is loaded using data for the comparison frame currently being processed if the pointing device is moved sufficiently so that the next comparison frame will not overlap the existing reference frame.