>From: "michael shaffer" <[EMAIL PROTECTED]> > Because my system is calibrated, I am not assuming. If my monitor is >truely gamma calibrated, and I use a gamma=2.2 working color space, then a >18% gray card's RGB value should be R=G=B=117 (see formulas below, they >aren't mine). I ask you ... under what circumstances would an 18% gray >card >be anything else? (you may also assume I have ambient illumination under >control.)
your assumption being that 0,0,0 is totally black and 255,255,255 is totally white in that 2.2 gamma colour space. Would be a pretty daft colour space as you can't get either on a monitor or printer and so you end up wasting a whole bunch of values that could never be properly expressed. generate an icm profile for you monitor (i.e. with a color sensor) and scanner and ignore the rgb values. Regards Ned _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp