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:
Jul. 01, 2014
Filed:
Feb. 14, 2011
Peter F. Holland, Sunnyvale, CA (US);
Vaughn T. Arnold, Scotts Valley, CA (US);
Peter F. Holland, Sunnyvale, CA (US);
Vaughn T. Arnold, Scotts Valley, CA (US);
Apple Inc., Cupertino, CA (US);
Abstract
A blend unit in a display pipe for processing pixels of video and/or image frames may include multiple blend stages, where each blend stage may include multiple levels for blending pixels according to a blend equation. The blending operation includes blending pixel color values and Alpha values. A multiplication may be performed at each blend level, necessitating Alpha value normalizations in the form of divisions to obtain pixel color values having a specified bit-length. Color value normalizations are not needed when the desired result is an actual color value. In order to reduce the compounding of errors that may result from the introduction of an error at each division, Alpha value normalizations may not be performed at each blend level, carrying the intermediate results forward in fractional form—through one or multiple blend stages—until the end of the blending operation. At or after the final blend level—in each blend stage, or in a final blend stage—a single division may performed, preventing the compounding of errors that would be incurred at each blend level if a division at each blend level were performed.