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. 01, 1987
Filed:
Apr. 29, 1985
Charles A Kunzinger, Morrisville, NC (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
NTSC composite color video signals captured in a freeze-frame videoconferencing system can be decomposed into luminance and chrominance components using simple digital addition and subtraction. The necessary apparatus includes a conventional color camera, an analog-to-digital converter, and a superframe buffer, organized into four field buffers. The analog signal is sampled at phase angles which are displaced at 135 degree increments. The preferred phase angles are 0, 135, 270, 45, 180, 315, 90 and 225 degrees relative to the phase of the color burst for the current scan line. Due to the reversal of the color burst phase on a frame-to-frame basis, a luminance or Y value can be obtained for each pel by adding the digital values stored in corresponding pel positions in corresponding fields (odd or even) in two successive frames of the same image. A chrominance or C value can be obtained by subtracting the same two values. The I and Q components of chrominance can be obtained directly as a result of the subtraction process at certain of the angles or indirectly through calculation at other of the angles.