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:
Oct. 28, 2008
Filed:
Dec. 30, 2003
James E. Nave, Denton, TX (US);
James E. Nave, Denton, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A video decoder () for receiving an input video signal and producing output signals for a digital display (), and involving automatic gain control (AGC) functions (), is disclosed. For each of the front-end and back-end AGC functions (), 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 () modifies its gain to unity if the front-end AGC function () 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.