This Month's Feature Article:
CHROMiX Stunt Profiles
by CHROMiX's Pat Herold and Steve Upton
- Using profiles for testing, analysis, or fun!
Over the years, we have created, garnered and collected several test profiles here at CHROMiX. These profiles are not generally for the purposes of viewing or printing out pretty-looking pictures, but are frequently for the exact opposite reason! These are test profiles, intended to help us analyze workflows, verfiy rendering intents, test to see if things we think are happening are in fact, actually happening.
When we send these newsletters out in email format, we consciously choose to keep it in plain text formatting, which does not allow images, so as to not fill up your inbox with unnecessary large files. However, you can also view this article in the "Reserved Articles" section of ColorWiki.com soon after its email release. There, this newsletter contains links and images showing the results of using these test profiles. http://www.colorwiki.com/wiki/Stunt_Profiles
RENDERING INTENT TESTERS
CX RGB RenderTest PCS=RGB.icc
We have taken a typical output printer profile and edited each rendering intent (B2A). When you print using this RGB output profile, your prints will give a different color hue with each rendering intent chosen. The "PCS" in the file name stands for Perceptual, Colorimetric and Saturation. If you use the Perceptual rendering intent during printing, the image will have a strong red cast. If you use Relative Colorimetric, the image will go green, and Saturation will look blue. P = R; C = G; S = B. Get it?
How can you use this profile?
Even though your software says that you are using the rendering intent of your choice when you are printing, sometimes it's nice to have something else confirm that fact. If you are using some new, experimental or beta software, this is a quick test to see that it really does print using each rendering intent as expected.
Once in awhile, we run into a printing system that does not offer a rendering intent choice, and you're left to guess which one they are using, or if they are grabbing the "default" rendering intent. This profile will give you an easy way to find the answer. The "Proofing" transforms of this profile are all normal. This means that if you assign this profile to an image, you will not see any of the strange transforms. For testing THAT part of a workflow, see the "Proofing Intent Testers."
CX CMYK RenderTest PCS=RGB.icc
This is a CMYK version of a rendering intent tester profile. As above, this will print with a different color cast for each rendering intent. This can be used on a RIP or other image processing software that requires a CMYK profile. The results are the same as what was described above with the RGB RenderTest.
- Perceptual = Red
- Colorimetric = Green
- Saturation = Blue
PROOFING INTENT TESTERS
CX RGB ProofTest PCS = RGB.icc
CX CMYK ProofTest PCS = RGB.icc
For these profiles we have altered each of the proofing (A2B) intents. If you assign this profile to an image it will appear to be heavily color casted depending on the rendering intent used by the software performing the conversion. In most software packages the Colorimetric intent is used so the image will appear to have a Green cast. Of course you need to choose the correct profile for the color model in which your image resides. If you just want to see if an application uses a profile at all, try the profile "CX scnr RGB->Gray.icc" below.
CX RGB scnr IntTest PCS=RGB.icc
This is an input profile version - again, showing a different color cast for each rendering intent. This can be used to verify what rendering intent is being used with input profiles like scanners or cameras. If you rely on your scanner software to apply a scanner profile, you might use this profile to verify that your scanner software is actually using the profile and is applying rendering intents correctly.
OTHER TEST PROFILES
CX scnr RGB->Gray.icc
When this profile is used, it will strip all saturation out of a color image, making it a black and white image. This (along with the weird.icc profile below) makes it easy to see if an embedded profile is actually working or not.
If you are dealing with a new workflow - a new printer interface, new computer - any situation where you have reason to doubt that your profile is actually being used - a little profile like this in place should remove all doubt.
We've all been in situations where we're setting up a new printer and trying to troubleshoot why the color is not coming out correctly. You're pulling your hair out trying to figure out if you've missed a button somewhere because everything you try just ends up with the same bad color. It is a small thing to plug one of these profiles into place in your workflow. If you don't see a change, then something is certainly wrong. If you do see the change these profiles cause, you at least have the reassurance that whatever is controlling your color management is doing its job correctly. It may not solve all your problems, but this is a simple, useful troubleshooting tool to keep in your color management bag of tricks for a rainy day.
CX output weird.icc
This one is a little more fun. Every rendering intent in this profile gives the image a different strange, mind-bending, retro 60's tie dye posterization look. There's no mistaking it when this profile is working. Psychedelic!
This is a monitor profile. Ever find yourself doubting whether your Vista operating system is using your monitor profile? This monitor profile gives a strange look, while still rendering your display readable.
CX Hue+45 abst.icc
This is an abstract profile that simply adds 45 degrees to the hue of all colors. In other words, all the colors in the image take a short spin around the color wheel. I always liked abstract profiles as they can capture interesting transformations for use again and again. With ColorThink Pro's ColorCast technology you can also permanently attach them to normal ICC profiles to create special effects, capture proofing color shifts or correct profiles.
All of the profiles mentioned in this article are available for download for free, courtesy of CHROMiX, from the public area of our Maxwell site. (www.mxwell.com)
As always, if you or any of your color management team are caught using these profiles on April 1st, CHROMiX will disavow any knowledge of them!
Thanks for reading,
Patrick Herold and Steve Upton
Tech support, CHROMiX