31. October 2002
Scanner profiling on a budget 2/2
In this article I will continue to describe how you can make your own scanner profiles.
The last article described the color targets and where to get them cheaply, while this article describes the free software you can use.

The Software
I've found a number of free programs for different platforms for making the profiles, but I'm going to focus on one here (for the Windows platform) called IPhotoMinusICC.
You need to download the "IPhotoMinus/ICC Profile Generator"
If you experience problems connecting to the download site you can alternatively download from here.

Although it is quite a capable program, keep in mind that it is freeware and of course not quite up to the standard of software that you pay for. But don't let the interface fool you. This program is capable of producing good profiles that can be used in Adobe Photoshop or elsewhere.

Setting up the scanner
Set up your scanner to output WITHOUT ANY COLOR MANAGEMENT OR IMAGE MANIPULATION if possible.
In this case I'm going to profile the Minolta Dimage Scan Multi Pro scanner and therefore I mount both of the targets (for Fuji and Kodak films) in the slide-holder and start the scanning process.
Don't scan at highest resolution. This will most often produce a file way to large for the profiling software. Aim for something in the size of 5-10MB which means something like 1200-1600ppi in 8 bit. I've chosen to scan in 16bit, but it's my experience that it really doesn't make any different for the resulting profile anyway.
Coming directly from the scanner the two images looks like this:


Fujichrome (left) and Ektachrome (right) color targets from Wolff Faust

I have cropped the scans to include ONLY the part of the image that contains the actual color target (I've cropped away anything else on left and right side and on the top of the target slide). This will make it easier for the profiling program to find the patches that it is going to measure.
We will later see how imprecise in colors they actually are, when scanning in this "RAW" mode.
(For the examples below, I'll only be using the Fujichrome target).

It is important that you from now one use the exact same setting of the scanner when you scan your photos.

Setting up the software
The IPhotoMinusICC software isn't the newest one you'll find however it does produce very good profiles.

Installation
Installing is straight forward. Remember the folder you installed to, because we are going to copy the color target description files we got on the diskettes into sub-folders later on.


The IPhoto Interface

Copying the target description files
First I must give the software the color target description file. This is done by copying the files from the diskettes to the folder called "wolf.q60" underneath the "IPhoto" folder (remember the location you installed it to).
Now simply start the diblook program from the IPhoto entry in your Start/Programs menu.

Open
Open the file(s) you've scanned (take one at a time, it makes thing easier).

ICC Preferences
Select the ICC Preferences dialog from the Files menu.
In this dialog you can select the description file of the target you've scanned. In this case we click on the "Wolf" and selects one of the Wolf Faust files. There are files for the Fuji targets and for the Kodak targets.
(Don't be confused by the "Kodak" and "Fuji" options. We need to choose the manufacturer of the targets which in our case is Wolf Faust).



When this is done move on to the "Profile Generation Tab". Here you can type in some meta information that you would like to appear in f.ex. the Photoshop profile dialog.



A very important thing to notice on this tab is the "Media White Point" options. You can select either GS0 which is the white patch on the target or you can select D50.
I get the best results from selecting the GS0 option.
You can experiment yourself with different settings and see what suits you best. Making the profile is just a few seconds away from here and it is easy to make a new one.
Now select the "CMM tab".



It is now revealed for us, that we are actually dealing with a color managed imaging software here and not just a profile generator. You can select your input profile your display and your printer profile. We are interested in the input profile, because this is the file that we are actually going to create!
Type in a filename of your own choice. Windows (depending on the type) puts its profiles into the c:\windows\system\color\ folder and you could do the same. For this test we can type in the name : c:\windows\system\color\test.icm. It has no impact on your profile wether or not we choose to use color management or wether or not we choose any display or printer profiles. I would perhaps suggest to just disable color management for this task.

Making the profile
Now select the Color/IT8_Q60 from the menu. The color patches are now "framed" by a black grid.



Now select the Color/GenerateDE menu entry and you profile is ready!

Misalignment
It can be that the black grid is not perfectly matched to the color-patches and in such a case we have to close the program and go and tweak an ini-file.
Find the file called de.ini in the folder to which you installed the program. Now try to change the entries:

AnchorLength=10
AnchorX=-4
AnchorY=4

until you get a perfect match.

Using the profile
Let's try out the profile.
In order to use the profiles you need some color management imaging software.
There aren't actually that many around. It could be Photoshop or Picture Windows Pro or another application, but be aware that if you are using an imaging tool that was bundled with your scanner or printer, it is likely that it ISN'T color managed.
In this article I've used free software so far, so why not find a free tool to make the color conversion for us?
If I'm going to present "before and after" images here, I need a tool that can convert from the scanner profile we made to the sRGB color space (read more about this in the former article) of the Internet.

LCMS Profile Tester
You can download exactly such a tool from here.
It's a small zip-file and you must extract the content to a folder and run the exe-file that was included.
If you experience problems connecting to the download site you can alternatively download from here.
You are then presented this interface:



Here I have selected my newly created profile as the Input Profile and I've selected the sRGB color space as the Monitor or Output Profile.
I have then loaded the scanned color target and saved a new copy that is converted to the sRGB space. Here is the result:


Before (left) and after (right)

Very well you might say, but what about a real photo?


Before (left) and after (right)



Before (left) and after (right)

I hope that it is clear here, that the profile corrected the somewhat red or magenta color cast that the original scans has.

I've also found that I can extract a lot of shadow details using this profile. But try it out yourself!

(Please observe that the LCMS Profile Tester tool will always save your images as 8-bit. You can load 16-bit images, but they are then converted to 8-bit when you save.)

Final comments
Is it really necessary to use a color target reproduced on the same kind of film stock that you are using for your photos? If you shoot on both Fuji film and Kodak films do you then really need to make a profile for both?
Well, in the theory: no.
Although I haven't demonstrated the difference here the two color targets does actually produce slightly different profiles, so I simply decided to use both (mostly on Fuji Provia RDPIII and Kodak E100S).

Color manipulation software or profiling software?
What puzzles me is, that so many scanners does not come with either color targets nor profiling software. Yes, I know that many high-end scanners does, but scanners in the lower end often comes with drivers that includes a lot of color manipulation options that simply duplicates the options you have in your imaging software already.
Why not just include a profiler and a color target and leave the color tweaking to the imaging software?

Anyway, if you happens to have a Minolta Dimage Scan Multi Pro scanner then perhaps you can use the profiles I made also (although you get the best result by actually profiling the scanner you use yourself).
You can download them here.


Links
PHOTOgraphical.NET :
• Scanner Profiling 1/2 The first half of this article.
Downloads:
• Download profiles for the Dimage Scan Multi Pro scanner
• IPhotoMinusICC profiling software. For building the profiles.
• LCMS Profile Tester. For using the profiles.

Other:
• www.coloraid.de Links to different color tools and information.
• Little CMS "A free color management engine in 100K". Here you will find another profiler for the Windows platform.
• Digital Light and Color "Serious Software for Serious Photographers". Good, low priced imaging software. Documents on many subjects, including color management.
• Wolf Faust Cheap IT 8.7 (ISO 12641) Scanner Color Calibration Targets.