Television – Image signal processing circuitry specific to television – Gray scale transformation
Reexamination Certificate
2003-12-30
2008-10-28
Ometz, David (Department: 2622)
Television
Image signal processing circuitry specific to television
Gray scale transformation
C348S685000, C348S528000, C348S255000, C348S679000, C348S194000
Reexamination Certificate
active
07443455
ABSTRACT:
A video decoder (10) for receiving an input video signal and producing output signals for a digital display (12), and involving automatic gain control (AGC) functions (20, 28), is disclosed. For each of the front-end and back-end AGC functions (20, 28), the AGC gain value applied is modified according to measurements of several attributes of the video signal, such as sync height, color burst amplitude, composite signal peak amplitude, and luma signal peak amplitude. The measurements are made, and the AGC gains are modified, on a frame-by-frame basis. Preferably, the AGC is modified using the one of the signal attributes that indicates the lowest gain. The back-end AGC function (28) modifies its gain to unity if the front-end AGC function (20) selected the luma signal peak amplitude for modifying its gain. A method for adjusting the rate of change of the AGC gain is also disclosed, in which gain increases are delayed and slowed following an AGC gain decrease because of an image-dependent signal attribute.
REFERENCES:
patent: 3829606 (1974-08-01), Kawamata et al.
patent: 4213097 (1980-07-01), Chiu et al.
patent: 4234892 (1980-11-01), Mochizuki et al.
patent: 4329713 (1982-05-01), Harford
patent: 4667163 (1987-05-01), Gay
patent: 4667242 (1987-05-01), Hagino
patent: 4807035 (1989-02-01), Sayliss
patent: 4989074 (1991-01-01), Matsumoto
patent: 5050192 (1991-09-01), Nawata
patent: 5268761 (1993-12-01), White
patent: 5671253 (1997-09-01), Stewart
patent: 5838390 (1998-11-01), Hankinson et al.
patent: 5867222 (1999-02-01), Norris et al.
patent: 6014180 (2000-01-01), Kawano
patent: 6049361 (2000-04-01), Kim
patent: 6219107 (2001-04-01), Renner et al.
patent: 6239848 (2001-05-01), Mycynek et al.
patent: 6281945 (2001-08-01), Jun et al.
patent: 6363127 (2002-03-01), Heinonen et al.
patent: 6404829 (2002-06-01), Sonu
patent: 6459458 (2002-10-01), Balaban
patent: 6483553 (2002-11-01), Jung
patent: 6678010 (2004-01-01), Jun
patent: 6678011 (2004-01-01), Yanagi et al.
patent: 6750906 (2004-06-01), Itani et al.
patent: 6833875 (2004-12-01), Yang et al.
patent: 6847407 (2005-01-01), Min
patent: 6882360 (2005-04-01), Zeidler
patent: 6894721 (2005-05-01), Okada et al.
patent: 6968166 (2005-11-01), Yang
patent: 6972800 (2005-12-01), Sano et al.
patent: 7065140 (2006-06-01), Ritter et al.
patent: 7110042 (2006-09-01), Bradley
patent: 7206030 (2007-04-01), Nave
patent: 7215703 (2007-05-01), Jensen et al.
patent: 7218905 (2007-05-01), Molnar et al.
patent: 2002/0005912 (2002-01-01), Yanagi et al.
patent: 2002/0059368 (2002-05-01), Reynolds
patent: 2002/0070796 (2002-06-01), Gay-Bellile et al.
patent: 2002/0089605 (2002-07-01), Min
patent: 2002/0118308 (2002-08-01), Dujmenovic
patent: 2004/0183953 (2004-09-01), Nave
patent: 2005/0280742 (2005-12-01), Jaffe
patent: 2006/0089813 (2006-04-01), Mushirahad et al.
patent: 2006/0170828 (2006-08-01), Muschallik et al.
patent: 2229333 (1990-09-01), None
“Composite Analog Video Signal—NTSC for Studio Applications”, ANSI/SMPTE Standard 170M-1994 (SMPTE, 1994).
“TVP5145: High-Quality, Single-Chip Digital Video Decoder for Video Applications”, Product Bulletin (Texas Instruments, 2002).
“SAA7115 NTSC/PAL/SECAM 9-bit Video Decoder” (Philips Semiconductors, 2001).
Brady III Wade J.
Désir Jean W
Franz Warren L.
Ometz David
Telecky , Jr. Frederick J.
LandOfFree
Automatic gain control based on multiple input references in... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automatic gain control based on multiple input references in..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic gain control based on multiple input references in... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4007715