Translations by Jean-Marc

Click <gui>Apply</gui>, and then click <gui>Apply</gui> in the window that appears. The applications that you chose will be downloaded and installed.

<em>Personal Package Archives (PPAs)</em> are software repositories designed for Ubuntu users and are easier to install than other third-party repositories.

The <app>Ubuntu Software Center</app> helps you to remove software that you no longer use.

Some applications depend on other applications to work properly. If you try to remove an application that is needed by another application, both will be removed. You will be asked to confirm whether you want this to happen before the applications are removed.

Add other repositories to extend the software sources Ubuntu uses for installation and upgrades.

Add/remove software

The recommended way of backing up your files and settings is to let a backup application manage the backup process for you. A number of different backup applications are available, like <app>Déjà Dup</app>.

Listed below are the most common locations of important files and settings that you may want to back up.

It is important to choose an appropriate <em>backup medium</em>, too. You need to store your backups on a device that has sufficient disk capacity for all of the backed-up files.

You only need to switch <gui>Visible</gui> on if you are connecting to this computer from another device. See <link xref="bluetooth-visibility"/> for more information.

If calibration hardware is connected the <gui>Calibrate…</gui> button will create a new profile.

Calibrating your camera is important to capture accurate colors.

How do I calibrate my camera?

Camera devices are calibrated by taking a photograph of a target under the desired lighting conditions. By converting the RAW file to a TIFF file, it can be used to calibrate the camera device in the color control panel.

You will need to crop the TIFF file so that just the target is visible. Ensure the white or black borders are still visible. Calibration will not work if the image is upside-down or is distorted by a large amount.

Calibrating your printer is important to print accurate colors.

How do I calibrate my printer?

Using an expensive device such as a ColorMunki works out cheaper only if you are profiling a large number of ink sets or paper types.

If you change your ink supplier, make sure you recalibrate the printer!

Calibrating your scanner is important to capture accurate colors.

How do I calibrate my scanner?

Scanner devices are incredibly stable over time and temperature and do not usually need to be recalibrated.

Calibrating your screen is important to display accurate colors.

How do I calibrate my screen?

Calibrating your screen should be a requirement if you're involved in computer design or artwork.

By using a device called colorimeter you accurately measure the different colors that your screen is able to display. By running <guiseq><gui>System Settings</gui><gui>Color</gui></guiseq> you can create a profile, and the wizard will show you how to attach the colorimeter device and what settings to adjust.

Screens change all the time - the backlight in a TFT will half in brightness approximately every 18 months, and will get yellower as it gets older. This means you should recalibrate your screen when the [!] icon appears in the color control panel.

Calibration and characterization are different things entirely.

What's the difference between calibration and characterization?

Many people are initially confused about the difference between calibration and characterization. Calibration is the process of modifying the color behavior of a device. This is typically done using two mechanisms:

The idea of calibration is to put a device in a defined state with regard to its color response. Often this is used as a day to day means of maintaining reproducible behavior. Typically calibration will be stored in device or systems specific file formats that record the device settings or per-channel calibration curves.

Note that a characterization (profile) will only be valid for a device if it's in the same state of calibration as it was when it was characterized.

In the case of display profiles there is some additional confusion because often the calibration information is stored in the profile for convenience. By convention it is stored in a tag called the <em>vcgt</em> tag. Although it is stored in the profile, none of the normal ICC based tools or applications are aware of it, or do anything with it. Similarly, typical display calibration tools and applications will not be aware of, or do anything with the ICC characterization (profile) information.

We support a large number of calibration devices.

What color measuring instruments are supported?

The Pantone Huey is currently the cheapest and best supported hardware in Linux.

Thanks to Argyll there's also a number of spot and strip reading reflective spectrometers supported to help you calibrating and characterizing your printers:

Calibration targets are needed to do scanner and camera profiling.

Which target types are supported?

Can I share my color profile?

This means if you share your color profile with somebody, you might be getting them <em>closer</em> to calibration, but it's misleading at best to say that their display is calibrated.

Where do I get color profiles?

How do I import color profiles?

In order to create a display profile, which includes both calibration and characterization data, you will need to use a special color measuring instruments called a colorimeter or a spectrometer.

You can be notified if your color profile is old and inaccurate.

Unfortunately we can't tell without recalibrating whether a device profile is accurate. We can use a simple metric of the amount of time since calibration to determine if a recalibrate is recommended.

Default monitor profiles do not have a calibration date.