Color Management

Status: Complete

Description

Color management is a neglected part of our desktop. Both Apple with OSX, and Microsoft with Windows 7 have made color management as an integral part of the desktop, and all core applications (Photoshop, Microsoft Word, etc) are able to import documents with embedded color spaces and do the right thing.

In GNOME 3.2, colord is an approved external dependency and many GNOME applications should use this to make a 100% color managed desktop.

There is a gnome-settings-daemon color plugin that does two main things:

• Watch for profile changes (listen to colord signals) and apply new or changed profiles to the display
• Watch for color calibration devices and start a color-management tool if one appears

There is a control-center panel that allows to associate color profiles with devices such as monitors, printers or scanners, and also lets you calibrate these devices if the necessary hardware/software for that are available. The focus of the panel will be more on letting a casual user fix occasional color issues than on all-out color management. The latter will be better served by explicit color management support in applications that need it, as well as a dedicated color-management tool.

Things the user can do in the control panel

• Setting a downloaded screen profile to an actual device
• Calibrating a scanner, printer, display and camera using hardware
• Setting the configuration default for all users (including gdm screen)
• Changing the default profiles for each device where auto-detection is not (yet) possible.
• Viewing details about the assigned profiles.

Things the user wants to do

• Scan in a photo [simple-scan asks colord for the default profile for the device and embeds it in the image]
• Display the photo [eog converts the embedded profile into the screen profile before displaying]
• Print the photo [CUPS registers devices with colord, and then foomatic and gstoraster get the correct profile for the print queue using colord]

Owner

Richard Hughes

Involved Parties

Richard Hughes, colord and gnome-color-manager (lots of other maintainers) GNOME designers

Current Status

At the moment, a few applications and frameworks already interface to colord for devices and color profiles.

• gnome-settings-daemon
• gnome-control-center
• Simple scan
• GNOME screenshot
• CUPS
• Ghostscript
• Foomatic
• the GTK+ print dialog

A design for the panel has been worked out. Here is an early mockup.

How to Help

Does your image load image files? Does it:

• Save embedded color profiles if the file is resaved?
• Read color profiles and use lcms2 to convert the image to the display profile?

Do you provide the user with a way of creating image files? Does it:

• Get the default colorspace for new documents from gnome-color-manager?

Do you show any images to the user? Do you:

• Get the display profile from gnome-color-manager or even using _ICC_PROFILE?

See http://colord.hughsie.com/ for more details about how colord works.