Getting RGB values for use outside of Photoshop

RH
Posted By
Ronald_Hirsch
Sep 25, 2006
Views
570
Replies
8
Status
Closed
I often am creating something in WordPerfect 12, where there are jpg graphic elements, and I want to match a color in the jpg image color for some type that I am adding.

So, I open the jpg graphic file in Photoshop, and read the RGB values for the color that I want to match. I then go back into WP12, select the type block involved, and bring up the custom color window for setting type colors.

I go into the advanced window, where I can set the RGB values, and enter the RGB values I just got from Photoshop. But, the match never seems to be quite right. Should it not be a "perfect" match? If not, what factors can cause the dfference?

When I print the final page, it too confirms that there is not a "perfect" match.

Ron Hirsch
Related Tags
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BL
Bob Levine
Sep 25, 2006
I’ve done the same thing for PowerPoint and always got an exact match. What are your color management settings?

Bob
PF
Peter_Figen
Sep 25, 2006
In order to get a perfect match, you will need to convert the PS file to Monitor RGB first and then read the numbers. Monitor RGB is all that non color managed applications understand.
GH
Gernot_Hoffmann
Sep 25, 2006
Ronald,

the JPEG is probably uncalibrated.
Choose working space sRGB, but don’t use ‘assign’
or ‘convert to’ by any profile.
If the image is looking at least ‘not bad’, then
measure the RGB values (the original numbers),
read the Hex values and apply them in old-fashioned
HTML code for the background.

No need to convert into an individual monitor space.
This would confuse further color management, which
is mostly based on a WELL defined working space.

Best regards –Gernot Hoffmann
PF
Peter_Figen
Sep 25, 2006
Gernot,

This is one of the times where you actually would want to convert to monitor RGB. It’s the only way to guarantee an exact match between PS and a non color managed application. It won’t cause any confusion. In fact, it will help Mr. Hirsh in his quest.
RH
Ronald_Hirsch
Sep 25, 2006
Thanks to all of you for your suggestions

My monitor was carefully calibrated using a Colorvision Spyder, and that profile loads at the end of my bootup. I do all my printing from QImage. And I have profiles I created applied to all the color printers that I use. So, no color profiles are normally applied by QImage or Photoshop.

II usually work in the Adobe RGB (1998) color spacein Photoshop (CS2), for all my digital photo images et al. I totally neglected to consider that things like screen captures images where I’m trying to match a color have no color profile assigned to them, And I did not assign anything when I was reading the RGB values.

Just for kicks, I opened an image, which uses Adobe RGB (1998), and then applied monitor color space, and then no color space. It makes quite a difference. The RGB values for a sampler point don’t change. But the visual color appearance sure does.

While WordPerfect is not color managed, the monitor profile should be reflected there, as it will impact all images on screen.

I’ll try some of the suggestions offered to get closer matches in the future.

Thanks again –

Ron Hirsch
GH
Gernot_Hoffmann
Sep 26, 2006
Ronald,

the match of a uniformly colored area in an image (your
JPEG) and a uniform color area as defined by the same
numbers in HTML doesn’t depend on the working space
and on the monitor profile, as long as the loaded RGB
data are not converted into ANY color space.

<http://www.fho-emden.de/~hoffmann/fountain.html>

Two backgrounds:
RGB=51/51/101 and RGB=190/189/229. Hex-numbers in source.

This doesn’t say anything about the appearance of this
image. Even if it looks terrible – the formalistic match is correct.
Has nothing to do with the question, whether the pair
image/area will look alike on different monitors or not
(this is a different kind of matching).

The method fails, if the JPEG is compressed once again.
Each JPEG compression can cause small shifts.
Therefore a matched pair image/area for an uncompressed
file will be no more matched for the compressed image
and the area as defined before.

Best regards –Gernot Hoffmann
GH
Gernot_Hoffmann
Sep 26, 2006
No comments ? I had wasted TWENTY minutes
for this test.

Best regards –Gernot Hoffmann
RH
Ronald_Hirsch
Sep 26, 2006
Hi Gernot,

I do appreciate all of your help suggestions, and the tests you ran.

Sorry I didn’t make that clear sooner.

Thanks again –

Ron Hirsch

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