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From: ahg@mentor.cc.purdue.edu (Allen Braunsdorf)
Newsgroups: comp.graphics
Subject: NTSC test pattern
Keywords: calibration of color digitizer  RGB  YIQ
Message-ID: <12947@mentor.cc.purdue.edu>
Date: 11 Aug 90 20:26:20 GMT
Organization: Purdue UNIX Group
Lines: 34

I've got my digitizing stuff hooked to my VCR now and I'm trying to
calibrate it properly.

The local cable company broadcasts a test pattern continuously on one
channel and I'm using that to try to get my color right.

My question is, what's right?  I know these test patterns vary, but
I've seen this one used a lot and thought someone out there might be
able to help me.

Here's a rough picture:

+---+---+---+---+---+---+---+
|   |   |   |   |   |   |   |
|   |   |   |   |   |   |   |
|   |   |   |   |   |   |   |
|   |   |   |   |   |   |   |
|   |   |   |   |   |   |   |
|   |   |   |   |   |   |   |
+---++--+-+-+--++---+---+---+
|    |    |    |            |
+----+----+----+------------+

Each outline is filled with a solid color.  The bars at the top are
greyish- white, yellow, cyan, green, violet, red, and blue.  The three
boxes are a dark blue, pure white, and a not as dark blue.  The rest of
the bottom row is dark black.

Does anyone know the proper YIQ or RGB values of these areas?  Since
the color strips aren't pure, I'm not sure where to begin.

---
Allen Braunsdorf			Purdue University Computing Center
cc.purdue.edu!ahg			UNIX Systems Programmer