Editing Profiles for Fun and Profit
This Month's Feature Article
Editing Profiles for Fun and Profit
by Pat Herold, CHROMiX's Tech Guru
The first thing we usually ask when a client announces that they would like to edit a profile is: "Now, why would you want to go and do a thing like that?"
The rule of thumb around CHROMiX is that if there's something wrong with a profile that requires an edit, then there was probably something wrong with the creation of the profile. Profiling software is quite advanced these days, and you generally don't find it making bad profiles when it is given good measurement data. So we will gently guide the user back to making sure the basics were covered when the profile was created. It is worthwhile to reprint the target and remeasure. Once in a while, an edit is necessary to adjust a profile that is not performing accurately, but it is the exception to the rule.
Now that I've got that warning out of the way, let's do an abrupt about-face and get excited about editing!
Steve Upton's article on Profile Editing from the ColorNews issue No. 3 presents a good overview of what features to look for, and is a great place to start learning about editing. The balance of this article will explore some practical ways that output profile editing can help you do more with already good profiles.
Three of our more popular editors are...
Kodak Colorflow Custom Color Tools
Try saying that three times quickly. Kodak is the manufacturer, "Colorflow" is the name of the family of products, and "Custom Color Tools" is the name of the actual profile editor. This product is gaining a lot of popularity among professional photographers because it operates as a Photoshop plug-in. You edit a profile by importing an image into Photoshop, altering the colors using the more common Photoshop image adjustment tools, and then you merely export your changes as a new profile.
If you are familiar with Photoshop, this gives you an interface that is pretty comfortable and can do just about anything you could want. You can't do anything too esoteric, like altering a specific color in a specific place in your image, andexpect that transformation to be included in the edit. But pretty much anything that can be done to alter the color in the entire image can be made into a profile edit.
What's more, Custom Color Tools works with just about every kind of profile out there: Input, output, device link profiles, monitor profiles, abstract profiles, and more. It can be used to edit in either direction, in any rendering intent. Custom Color Tools is also one of the few applications that will CREATE (not just edit) ABSTRACT profiles.
Gretag Macbeth ProfileMaker ProfileEditor
This is a good example of an editor that has all the advanced features that make an editor really useful. It has a large assortment of the usual useful adjustment tools - but I really like their "Selective Color" tool. Here you can pick precisely the color you want to affect, and then specify exactly where in the spectrum you want it to go. When you are selecting a color (say blue for instance) you can choose the precise hue, you have total control over what luminosity range that blue includes, as well as the specific chroma (saturation) of the blue. In addition, you can specify how wide a range is included in each of these areas. And then you have the same pin-point accuracy in determining where in the spectrum you are going to move that edited color.
A nice feature added in version 5 of ProfileEditor is the ability to save multiple edits. Now, when you make several edits in the Selective Color tool, you can save all those edits all together, and easily apply them to another profile to get the same effect.
HOW TO USE IT
Let's say that you want to add saturation to your profile. A global correction would likely add color to everything, including neutrals and shadows. Do you really want the dark green grass in the shadow of a tree to be a brighter green like the rest of the green in the image? Using the Selective Color tool, you can taper off the saturation so that it does not affect neutrals and shadows to the same degree as the rest of the spectrum.
Do you print portraits frequently? The Selective Color tool can be used to edit only the areas of flesh tones that are of a dull and lifeless character, and move them gradually in the direction of more warmth or saturation. You pick these colors with a simple eye dropper tool. This technique has been commonly used to improve color in high production workflows where individual "hand-correcting" is not possible. The profile is used to "juice up" the flesh tones so people look a little more healthy. Note that this does not move all flesh tones, but only those you've picked that have a gray or near-white complexion. It will make a "gray" face look better, while leaving the healthy ones alone.
Gretag Macbeth i1Match Profile Editor
Are you intrigued at the idea of profile editing, but thought it was too expensive? The i1Match version of the Gretag profile editor is a nice little editor that you can upgrade to for less than $100. It is easy to use and comes from one of the most respected names in the industry.
Naturally, this comes with some limitations:
- It only edits output profiles.
- It is limited to lightness/contrast, saturation, gray balance color adjustment, and overall color adjustment.
- These adjustments are rather broad; they affect the whole spectrum. There is no way to narrow the effected colors down to a specific hue, chroma & luminosity.
A COST SAVINGS STORY
I once was making profiles for a series of Gretag Mileca printers back in the early days of digital printing onto photographic (silver halide) paper. The colors came out perfectly when printed through these profiles, but customers started complaining that their black and white images were "partially" colored. The original customer image was clearly black and white but, when printed, the woman's checkerboard-patterned dress came out a dark cyan while everything else in the image looked like a normal B & W image. We scratched our heads over that one. How does a printer make up its mind to just colorize certain parts of a picture? A thorough investigation showed that the printers were operating correctly, measurements were accurate, and in every other respect these were good profiles.
We finally discovered that the company was using the same Kodak paper on these digital printers that they were using on their conventional (analog) MSP printers and minilabs. Kodak had a special, new digital photographic paper, but the company had rejected it because it was twice the price of the regular paper. The digital paper was designed to avoid "text flare". A digital printer is capable of slamming a lot more light at the dyes in the paper emulsion than a conventional printer (especially when printing black), and if the paper can't handle it, the dyes will bleed into areas next to the pixels where they were exposed. Hence, what should have been "white" portions between the checkerboard pattern turned out to have a bluish dye creeping into it. This is what made the whole dress look colored.
What to do? Of course, the correct thing to do would be to buy the digital paper. But the idea of suddenly doubling the cost of materials was making the financial department balk. "Gee, isn't there any way you can make this work without having to go to this expensive paper?"
Enter the profile editor. I edited the printer direction of the profiles to taper off just the very blackest section of the gamut. Instead of running diagonally straight down to zero, the curves had a bit of a "J" shape to them so that black would actually get printed as "almost black" gray. We had to experiment with how much of this "roll-off" was needed to get rid of the colored artifacts while still printing a good, rich, dark print. But a happy medium was reached, they were able to stay on their existing media, and by one estimate the company saved $117,000 a year in paper savings alone.
All right, individual results may vary - and you may not save $100,000 on your home inkjet. But it does get you thinking about what one humble, little profile edit can do!
Thanks for reading,
-Patrick Herold CHROMiX