F-Spot

What's color management

When you capture a photo and look at it on a display, it looks different than on a camera's preview display or on any other display. It will also look different when you print it. This is because every device has unique color reproduction capabilities.

Color management system (CMS) is a tool to achieve reliable color reproduction for both display and output (e.g. a printer). A CMS relies on color profiles to map original colors to the color that a device can reproduce so that colors will appear the same way everywhere — on a computer LCD monitor, on a print from your local photolab etc.

What's a color profile

A color profile is a file with either .icc (thus its is often called an ICC profile) or .icm extension that describes how device's colors correspond to a universal description of colors.

There are several types of profiles:

• Input device profile. It's profile for a camera or a profile that an application like XSane embeds into a scanned image.
• Working space profile. It's a profile that describes color space in which all operations are done inside an application. Usually very wide gamut profiles like AdobeRGB1998 or ProPhotoRGB are used for that.
• Display profile. It's a profile for a monitor.
• Output profile. This is usually a profile for you printer.

Currently F-Spot allows setting only display and output profiles. All color operations are done in sRGB color space.

How to get my screen/printer color profile

There are few ways to get a color profile.

From CD or Internet

Many hardware manufacturers put color profiles into CD in the bundle. If you have one (from monitor or printer), you can use it. Or you can download it from the Internet (usually, from support section of the manufacturer's web site). Some camera manufacturers (Nikon, Canon) also provide ICC profiles.

Calibrating and profiling

Best results can be achieved by calibrating and profiling devices with a measurement device. It is not so difficult, but it means that you need a spectrophotometer to do all measurements and create an ICC profile.

If you are on Windows or Mac OS X, you can use manufacturer's software coming with a spectrophotometer. On Linux you will have to use either Argyll, which is a set of versatile command line tools, or LProf, which has a graphical user interface.

Please refer to documentation of third party hardware and software vendors for details.

Embedding

Image formats themselves (such as TIFF, JPEG, PNG...) may contain embedded color profiles. If color management is enabled, F-Spot looks for such embedded profiles and takes them into consideration.

How to use color management in F-Spot

Color management in F-Spot can use only RGB profiles at this time (and you can't see other profiles in the F-Spot).

1. Copy your color profiles into the /usr/share/color/icc or /usr/local/share/color/icc
2. Enable the color management with the Edit » Preferences menu.
3. Select Display and Output profiles

Note: You can use xicc to load ICC profile to display and use the loaded profile from F-Spot. 
Just mark the checkbox "Try to use the system display profile".