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:
Apr. 21, 1998
Filed:
Aug. 09, 1994
John C Sievers, Wakefield, MA (US);
John E Bruder, Arlington, MA (US);
Picture Tel Corporation, Peabody, MA (US);
Abstract
A method and apparatus for selectively pre-filtering signal representations of images representing data to be transmitted and substantially maintaining the frame rate of transmission by reducing the number of expected bits needed to transmit the selected block portions of an image frame. The pre-filter uses the quantizer state value representative of the number of expected bits required for each block portion of the image as well as a weighted energy error value based on the preselected coding method of the block of the image being transmitted to determine a level of prefiltering required. The prefilter, for example, may be a multi-tap filter having a center tap and outer taps with amplitudes based on the quantizer state and weighted error energy values.