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:
Aug. 24, 2004
Filed:
Feb. 18, 2000
Eric Viscito, San Francisco, CA (US);
Zhijun Tong, Fremont, CA (US);
Conexant Systems, inc., Newport Beach, CA (US);
Abstract
A video quantizer provides for performing quantization adaptively in accordance with perceptual masking characteristics of the human visual system. In a preferred MPEG encoder-IC, a block-based activity quantization modification or “activity-modification” is formed from the combined correlation of block-energy and edge analyses. A luminance-sensitivity modification is then formed and correlated with the activity modification to form an intermediate modification. A nominal-quantization modification is further formed and correlated with the intermediate modification, which is then limited and correlated with a nominal quantization value to form a base modification. Next, a positional-sensitivity modification is formed as a perimeter offset, which offset is correlated with the base modification to form a modified quantization value, and which modified quantization value is then rounded and returned to a rate controller.