I signal

I signal

[′ī ‚sig·nəl]
(electronics)
The in-phase component of the chrominance signal in color television, having a bandwidth of 0 to 1.5 megahertz, and consisting of +0.74(R-Y) and -0.27(B-Y), where Y is the luminance signal, R is the red camera signal, and B is the blue camera signal.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.