Two algorithms that are suitable for deriving the blanking level of a National Television Systems Committee (NTSC) composite video signal are described. One method consists of averaging digitized color-burst samples taken from successive scan lines. A second method involves processing a group of samples taken from a single burst interval. Either algorithm used in a hybrid clamping arrangement results in automatic drift compensation and the ability to tie the back porch or sync tip to a predetermined digital output code. This aids in matching the analog signal to the input of the analog-to-signal (A/D) converter for maximum signal-to-noise ratio (SNR). In analyzing the effect of additive noise and timing jitter, it was found that both algorithms are, generally, more vulnerable than a conventional keyed clamper.
N. R. Cox and D. W. Irwin, "Hybrid Clamping in NTSC Digital Video Equipment," IEEE Transactions on Broadcasting, Institute of Electrical and Electronics Engineers (IEEE), Jan 1992.
The definitive version is available at http://dx.doi.org/10.1109/11.127422
Electrical and Computer Engineering
Keywords and Phrases
ADC; NTSC; National Television Systems Committee; SNR; Algorithms; Analog Signal; Automatic Drift Compensation; Blanking Level; Color Television; Composite Video Signal; Digital Codecs; Digital Color Burst Samples; Digital Output Code; Digital Processing; Digital Video Equipment; Hybrid Clamping; Signal-To-Noise Ratio; Video Equipment; Video Signals
International Standard Serial Number (ISSN)
Article - Journal
© 1992 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.