RE: purpose of Granger rainbow chart?
RE: purpose of Granger rainbow chart?
- Subject: RE: purpose of Granger rainbow chart?
- From: Roger Breton <email@hidden>
- Date: Sun, 07 Mar 2010 12:15:29 -0500
A "Granger" rainbow can be created with the tools of Photoshop. Not too
difficult to do with a basic gradients mastery. What's unique about this
kind of image is its sheer color appearance, which always glues me to the
screen, every time I have one up on my display -- everything seems so
perfect in it.
It's a very good test image for use with any color transforms. Why? Because,
other than showing the huge loss of saturation when going from RGB to CMYK,
for example, it also brutally brings out the underlying behaviour of a color
profile. Bad feature of an output profile like tonal discontinuities
immediately jump out.
Color profiling is both a science and an art. Sometimes, smoothness is more
important than colorimetric accuracy. Although this kind of synthetic
imagery is a quite potent analytical tool, its reproduction must never be
more important than real world imagery reproduction, IMHO.
Yet, it remains a classic. Thank you Mr. Ed Granger, PhD. I'll never forget
meeting you in Rochester during the 2001 AIC meeting.
Is that the same "Granger"?
Best / Roger Breton
> A quick follow-up. The chart described at the luminous landscape page is
> quite different than the TIFF image downloadable from the Real World Color
> Management website [4], which seems to be just the outer edge of an HSL
> cylinder. Both charts contain the same colors, just rearranged a bit. [HSL
> "lightness" is defined as .5*max(R', G', B') + .5*min(R', G', B').]
>
> Cheers,
> Jacob Rus
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden