The ICC was formed to created a standard way to convert colors from one device to another, a color management system (CMS). This was origianlly done for desktop publishing. Scanners, monitors, and printers all have different gamuts, or color ranges, as well as different gammas, and color spaces. Monitors, scanners, cameras, and inkjet printers all talk in the RGB color space, while postscript and pre-press printers talk CMY or CMYK.

In order to translate colors between all these devices a standard intermediate color space was needed. The ICC adopted the CIE's Lab color space which represents the full visual range. Next they developed the icc profiles which define the gamut for a device and the transform between the device color space and Lab. In theory if you have profiles for your monitor and scanner, and you have and editor that understands CMS, every image you scan would look correct on your monitor. In practice the average user does not have these things.

The last step for the ICC was to get the CMS integrated into the operating system so that all programs could use it. Both Windows and Mac have the CMS built into the OS. Supposedly any application that wants to display accurate images should use these systems but few do. Mostly it is used by DTP and higher end image editors like Photoshop. Even the OS doesn't use it when displaying the desktop and window decorations. This can keep themes from looking the same accross all systems since monitors can have different profiles. Mac users feel free to correct me on that. It seems to me that if they want developers to use CMS then the OS should be using it. Yes I know on *nix systems it would be the desktop system and window manager that would need to use it.

We've all seen the effect of no gamma/color correction. The web has plenty of mages that look to light or dark because they were created on systems that had a different gamma than ours. Even I'm responsible for doing it. My system was calibrated to a display gamma fo 1.0 when I made my site which makes my site look nice and bright. Untill I made these pages the logo was still set for gamma 1.0. Here are two versions of the logo, the first is the original gamma 1.0 and the second is for mac gamma 1.75:

As you can see the three look very different. On a typical pc the main image should look correct with the other two looking to dark. On a mac the second image above should look correct, the first washed out, and the top image to dark. And then there is my system were both the pc and mac images look washed out.

When the w3c was creating HTML 4 they descided to add support for color correction to HTML. But they needed a standard default color space for all past and future web pages. This is the reason that the w3c has specified that all unlabled colors and images on the web should be assumed to be in the srgb color space (gamma 2.2). Asside from providing a standard color space it should provide some compatability with existing images since it is between the two previous gammas. It is also the color space for HDTV.

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