Translations by Satoko Rokujo

Click the Bluetooth icon on the top bar and select <gui>Send Files to Device</gui>.

If there are many devices, you can limit the list to only specific device types using the <gui>Device type</gui> drop-down.

Send files from the Bluetooth settings

Select the device to send files to from the list on the left. The list only shows devices you've already connected to. See <link xref="bluetooth-connect-device"/>.

In the device information on the right, click <gui>Send Files</gui>.

You can turn Bluetooth on to use Bluetooth devices and send and receive files, but turn it off to conserve power. To turn Bluetooth on, click the Bluetooth icon in the menu bar and click <gui>Turn On Bluetooth</gui>.

You can turn Bluetooth on to use Bluetooth devices and send and receive files, but turn it off to conserve power. To turn Bluetooth on, click the Bluetooth icon on the top bar and switch <gui>Bluetooth</gui> on.

Each device can have multiple profiles assigned to it, but only one profile can be the <em>default</em> profile. The default profile is used when there is no extra information to allow the profile to be chosen automatically. An example of this automatic selection would be if one profile was created for glossy paper and another plain paper.

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

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.

The resulting profile is only valid under the lighting condition that you acquired the original image from. This means you might need to profile several times for <em>studio</em>, <em>bright sunlight</em> and <em>cloudy</em> lighting conditions.

There are two ways to profile a printer device:

Using a photospectrometer device like the Pantone ColorMunki

Downloading a printing a reference file from a color company

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!

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

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.

LED screens also change over time, but a much slower rate than TFTs.

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:

Changing controls or internal settings that it has

Applying curves to its color channels

Characterization (or profiling) is <em>recording</em> the way a device reproduces or responds to color. Typically the result is stored in a device ICC profile. Such a profile does not in itself modify color in any way. It allows a system such as a CMM (Color Management Module) or a color aware application to modify color when combined with another device profile. Only by knowing the characteristics of two devices, can a way of transferring color from one device representation to another be achieved.

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?

GNOME relies on the Argyll color management system to support color instruments. Thus the following display measuring instruments are supported:

Gretag-Macbeth i1 Pro (spectrometer)

Gretag-Macbeth i1 Monitor (spectrometer)

Gretag-Macbeth i1 Display 1, 2 or LT (colorimeter)

X-Rite i1 Display Pro (colorimeter)

X-Rite ColorMunki Design or Photo (spectrometer)

X-Rite ColorMunki Create (colorimeter)

X-Rite ColorMunki Display (colorimeter)

Pantone Huey (colorimeter)

MonacoOPTIX (colorimeter)

ColorVision Spyder 2 and 3 (colorimeter)

Colorimètre HCFR (colorimeter)

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

Calibration targets are needed to do scanner and camera profiling.

Which target types are supported?

The following types of targets are supported:

CMP DigitalTarget

ColorChecker 24

ColorChecker DC

ColorChecker SG