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:
Oct. 23, 2001
Filed:
Apr. 04, 2000
Marc P. Schuyler, Mountain View, CA (US);
Susie J. Wee, Mountain View, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
This disclosure provides a block-based compression system which uses a variable size search window, to thereby substantially reduce the time required for compression. In a MPEG-2 system, square tiles are processed left to right in rows, beginning at the top of a frame and finishing at the bottom. The absolute value of pixel differences for already-processed “northwest,” “north,” “northeast” and “west” neighbor tiles are separately summed and compared to a threshold. If any of the sums exceeds the threshold or if any of the neighbor tiles are unavailable (e.g., the tile under consideration is in the top row or the left-most column), then a maximum size search window is used to determine the tile's “closest match” in a prior image frame and the associated motion vector. If none of the exceed the threshold, then a relatively smaller size search window is used. The size of the smaller window is selected in dependence upon the motion vectors for the neighbor tiles, e.g., if the neighbor tiles have similar motion vectors and small residuals, the search for the “closest match” is performed in a relatively small area.