[gnome-user-docs] Add some intial documentation and figures for color management
- From: Richard Hughes <rhughes src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gnome-user-docs] Add some intial documentation and figures for color management
- Date: Thu, 25 Aug 2011 09:37:17 +0000 (UTC)
commit d75751ee02d805358e1a3ceafaa973569419253c
Author: Richard Hughes <richard hughsie com>
Date: Wed Aug 24 21:49:11 2011 +0100
Add some intial documentation and figures for color management
gnome-help/C/color-assignprofiles.page | 46 +++++++++
gnome-help/C/color-calibrate-camera.page | 38 ++++++++
gnome-help/C/color-calibrate-printer.page | 48 ++++++++++
gnome-help/C/color-calibrate-scanner.page | 35 +++++++
gnome-help/C/color-calibrate-screen.page | 45 +++++++++
.../C/color-calibrationcharacterization.page | 63 ++++++++++++
gnome-help/C/color-calibrationdevices.page | 41 ++++++++
gnome-help/C/color-calibrationtargets.page | 47 +++++++++
gnome-help/C/color-canshareprofiles.page | 38 ++++++++
gnome-help/C/color-gettingprofiles.page | 43 +++++++++
gnome-help/C/color-missingvcgt.page | 29 ++++++
gnome-help/C/color-notspecifiededid.page | 39 ++++++++
gnome-help/C/color-whatisprofile.page | 39 ++++++++
gnome-help/C/color-why-calibrate.page | 41 ++++++++
gnome-help/C/color-whyimportant.page | 100 ++++++++++++++++++++
gnome-help/C/color.page | 36 +++++++
gnome-help/C/figures/color-average.png | Bin 0 -> 16381 bytes
gnome-help/C/figures/color-camera.png | Bin 0 -> 110839 bytes
gnome-help/C/figures/color-display.png | Bin 0 -> 103602 bytes
gnome-help/C/figures/color-printer.png | Bin 0 -> 96610 bytes
gnome-help/C/figures/color-profile-default.png | Bin 0 -> 16034 bytes
gnome-help/C/hardware.page | 1 +
gnome-help/Makefile.am | 21 ++++
23 files changed, 750 insertions(+), 0 deletions(-)
---
diff --git a/gnome-help/C/color-assignprofiles.page b/gnome-help/C/color-assignprofiles.page
new file mode 100644
index 0000000..0b6aa03
--- /dev/null
+++ b/gnome-help/C/color-assignprofiles.page
@@ -0,0 +1,46 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-assignprofiles">
+
+ <info>
+ <link type="guide" xref="hardware#color"/>
+ <link type="seealso" xref="color-whatisprofile"/>
+ <link type="seealso" xref="color-whycalibrate"/>
+ <desc>Look in <guiseq><gui>System Settings</gui><gui>Color</gui></guiseq> for the option to change this.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>How do I assign profiles to devices?</title>
+
+ <p>
+ Open <guiseq><gui>System Settings</gui><gui>Color</gui></guiseq>,
+ and click the device that you wish to add a profile to.
+ </p>
+ <p>
+ By clicking <gui>Add profile</gui> you can select an existing
+ profile or import a new file.
+ </p>
+ <p>
+ 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.
+ </p>
+
+ <figure>
+ <desc>You can make a profile default by changing it with the radio button.</desc>
+ <media type="image" mime="image/png" src="figures/color-profile-default.png"/>
+ </figure>
+
+ <p>
+ If calibration hardware is connected the <gui>Calibrate...</gui>
+ button will create a new profile.
+ </p>
+
+</page>
diff --git a/gnome-help/C/color-calibrate-camera.page b/gnome-help/C/color-calibrate-camera.page
new file mode 100644
index 0000000..c371b7e
--- /dev/null
+++ b/gnome-help/C/color-calibrate-camera.page
@@ -0,0 +1,38 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-calibrate-camera">
+
+ <info>
+ <link type="guide" xref="color#calibration"/>
+ <link type="seealso" xref="color-calibrationtargets" />
+ <link type="seealso" xref="color-calibrate-printer" />
+ <link type="seealso" xref="color-calibrate-scanner" />
+ <link type="seealso" xref="color-calibrate-screen" />
+ <desc>Calibrating your camera is important to capture accurate colors.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>How do I calibrate my camera?</title>
+
+ <p>
+ 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.
+ </p>
+
+ <note style="tip">
+ <p>
+ The resulting profile is only valid under the lighting condition
+ that you aquired 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.
+ </p>
+ </note>
+
+</page>
diff --git a/gnome-help/C/color-calibrate-printer.page b/gnome-help/C/color-calibrate-printer.page
new file mode 100644
index 0000000..ea4d963
--- /dev/null
+++ b/gnome-help/C/color-calibrate-printer.page
@@ -0,0 +1,48 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-calibrate-printer">
+
+ <info>
+ <link type="guide" xref="color#calibration"/>
+ <link type="seealso" xref="color-calibrate-scanner" />
+ <link type="seealso" xref="color-calibrate-screen" />
+ <link type="seealso" xref="color-calibrate-camera" />
+ <desc>Calibrating your printer is important to print accurate colors.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>How do I calibrate my printer?</title>
+
+ <p>
+ There are two ways to profile a printer device:
+ </p>
+
+ <list>
+ <item><p>Using a photospectrometer device like the Pantone ColorMunki</p></item>
+ <item><p>Downloading a printing a reference file from a color company</p></item>
+ </list>
+
+ <p>
+ Using a color company to generate a printer profile is usually the
+ cheapest option if you only have one or two different paper types.
+ By downloading the reference chart from the companies website you
+ can then send them back the print in a padded envelope where they
+ will scan the paper, generate the profile and email you back an
+ accurate ICC profile.
+ </p>
+ <p>
+ 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.
+ </p>
+
+ <note style="tip">
+ <p>
+ If you change your ink supplier, make sure you recalibrate the printer!
+ </p>
+ </note>
+
+</page>
diff --git a/gnome-help/C/color-calibrate-scanner.page b/gnome-help/C/color-calibrate-scanner.page
new file mode 100644
index 0000000..e8fea02
--- /dev/null
+++ b/gnome-help/C/color-calibrate-scanner.page
@@ -0,0 +1,35 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-calibrate-scanner">
+
+ <info>
+ <link type="guide" xref="color#calibration"/>
+ <link type="seealso" xref="color-calibrationtargets" />
+ <link type="seealso" xref="color-calibrate-printer" />
+ <link type="seealso" xref="color-calibrate-screen" />
+ <link type="seealso" xref="color-calibrate-camera" />
+ <desc>Calibrating your scanner is important to capture accurate colors.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>How do I calibrate my scanner?</title>
+
+ <p>
+ You scan in your target file and save it as an uncompressed TIFF file.
+ You can then click <gui>Calibrate...</gui> from
+ <guiseq><gui>System Settings</gui><gui>Color</gui></guiseq> to
+ create a profile for the device.
+ </p>
+
+ <note style="tip">
+ <p>
+ Scanner devices are incredibly stable over time and temperature
+ and do not usually need to be recalibrated.
+ </p>
+ </note>
+
+</page>
diff --git a/gnome-help/C/color-calibrate-screen.page b/gnome-help/C/color-calibrate-screen.page
new file mode 100644
index 0000000..ebbeba0
--- /dev/null
+++ b/gnome-help/C/color-calibrate-screen.page
@@ -0,0 +1,45 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-calibrate-screen">
+
+ <info>
+ <link type="guide" xref="color#calibration"/>
+ <link type="seealso" xref="color-calibrate-printer" />
+ <link type="seealso" xref="color-calibrate-scanner" />
+ <link type="seealso" xref="color-calibrate-camera" />
+ <desc>Calibrating your screen is important to display accurate colors.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>How do I calibrate my screen?</title>
+
+ <p>
+ Calibrating your screen is very easy to do and should be a hard
+ requirement if you're involved in computer design or artwork.
+ </p>
+ <p>
+ 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 easily create a profile, and the wizard will show you how
+ to attach the colorimeter device and what settings to adjust.
+ </p>
+
+ <note style="tip">
+ <p>
+ 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.
+ </p>
+ <p>
+ LED screens also change over time, but a much slower rate than TFTs.
+ </p>
+ </note>
+
+</page>
diff --git a/gnome-help/C/color-calibrationcharacterization.page b/gnome-help/C/color-calibrationcharacterization.page
new file mode 100644
index 0000000..0f1109d
--- /dev/null
+++ b/gnome-help/C/color-calibrationcharacterization.page
@@ -0,0 +1,63 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-calibrationcharacterization">
+
+ <info>
+
+ <link type="guide" xref="color#calibration"/>
+
+ <desc>Calibration and characterization are different things entirely.</desc>
+
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>What's the difference between calibration and characterization?</title>
+ <p>
+ 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:
+ </p>
+ <list>
+ <item><p>Changing controls or internal settings that it has</p></item>
+ <item><p>Applying curves to its color channels</p></item>
+ </list>
+ <p>
+ The idea of calibration is to put a device is 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.
+ </p>
+ <p>
+ 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.
+ </p>
+ <note>
+ <p>
+ Note that a characterization (profile) will only be valid for a device
+ if it is in the same state of calibration as it was when it was
+ characterized.
+ </p>
+ </note>
+ <p>
+ 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.
+ </p>
+
+</page>
diff --git a/gnome-help/C/color-calibrationdevices.page b/gnome-help/C/color-calibrationdevices.page
new file mode 100644
index 0000000..05ce7bc
--- /dev/null
+++ b/gnome-help/C/color-calibrationdevices.page
@@ -0,0 +1,41 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-calibrationdevices">
+
+ <info>
+
+ <link type="guide" xref="color#calibration"/>
+
+ <desc>We support a huge number of calibration devices.</desc>
+
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>What color measuring instruments are supported?</title>
+
+ <p>
+ GNOME relies on the ArgyllCMS project to support color instruments.
+ Thus the following display measuring instruments are supported:
+ </p>
+
+ <list>
+ <item><p>Gretag-Macbeth Eye-One Pro (spectrometer)</p></item>
+ <item><p>Gretag-Macbeth Eye-One Monitor (spectrometer)</p></item>
+ <item><p>Gretag-Macbeth Eye-One Display 1, 2 or LT (colorimeter)</p></item>
+ <item><p> X-Rite ColorMunki Design or Photo (spectrometer)</p></item>
+ <item><p> X-Rite ColorMunki Create (colorimeter)</p></item>
+ <item><p>Pantone Huey (colorimeter)</p></item>
+ <item><p>MonacoOPTIX (colorimeter)</p></item>
+ <item><p>ColorVision Spyder 2 and 3 (colorimeter)</p></item>
+ <item><p>ColorimÃtre HCFR (colorimeter)</p></item>
+ </list>
+
+ <note style="tip">
+ <p>The Pantone Huey is currently the cheapest and best supported hardware in Linux.</p>
+ </note>
+
+</page>
diff --git a/gnome-help/C/color-calibrationtargets.page b/gnome-help/C/color-calibrationtargets.page
new file mode 100644
index 0000000..457be61
--- /dev/null
+++ b/gnome-help/C/color-calibrationtargets.page
@@ -0,0 +1,47 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-calibrationtargets">
+
+ <info>
+
+ <link type="guide" xref="color#calibration"/>
+
+ <desc>Calibration targets are needed to do scanner and camera profiling.</desc>
+
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>Which target types are supported?</title>
+
+ <p>
+ The following types of targets are supported:
+ </p>
+
+ <list>
+ <item><p>CMP DigitalTarget</p></item>
+ <item><p>ColorChecker 24</p></item>
+ <item><p>ColorChecker DC</p></item>
+ <item><p>ColorChecker SG</p></item>
+ <item><p>i1 RGB Scan 14</p></item>
+ <item><p>LaserSoft DC Pro</p></item>
+ <item><p>QPcard 201</p></item>
+ <item><p>IT8.7/2</p></item>
+ </list>
+
+ <note style="tip">
+ <p>
+ You can purchase targets from well-known vendors like KODAK, X-Rite
+ and LaserSoft in various online shops.
+ </p>
+ <p>
+ Alternatively you can buy
+ targets from <link href="http://www.targets.coloraid.de/";>Wolf Faust</link>
+ at a very fair price.
+ </p>
+ </note>
+
+</page>
diff --git a/gnome-help/C/color-canshareprofiles.page b/gnome-help/C/color-canshareprofiles.page
new file mode 100644
index 0000000..2bf5a99
--- /dev/null
+++ b/gnome-help/C/color-canshareprofiles.page
@@ -0,0 +1,38 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-canshareprofiles">
+
+ <info>
+ <link type="guide" xref="color#calibration"/>
+ <link type="seealso" xref="color-whatisprofile"/>
+ <desc>Sharing color profiles is nevera good idea as hardware changes over time.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>Can I share my color profile?</title>
+
+ <p>
+ Color profiles that you have created yourself are specific to the
+ hardware that you calibrated for.
+ My DreamColor LP2480zx has been powered for a few hundred hours, and
+ is going to have a very different color profile to a similar display
+ with the next serial number if it's been lit for a thousand hours.
+ </p>
+ <p>
+ 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 thier display is calibrated.
+ </p>
+
+ <note style="warning">
+ <p>
+ You should carefully check the redistribution conditions for profiles
+ downloaded from vendor websites or that were created on your behalf.
+ </p>
+ </note>
+
+</page>
diff --git a/gnome-help/C/color-gettingprofiles.page b/gnome-help/C/color-gettingprofiles.page
new file mode 100644
index 0000000..12e39b7
--- /dev/null
+++ b/gnome-help/C/color-gettingprofiles.page
@@ -0,0 +1,43 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-gettingprofiles">
+
+ <info>
+ <link type="guide" xref="color#profiles"/>
+ <link type="seealso" xref="color-why-calibrate"/>
+ <link type="seealso" xref="color-whatisprofile"/>
+ <link type="seealso" xref="color-missingvcgt"/>
+ <desc>Color profiles are provided by vendors and can be generated yourself.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>Where do I get color profiles?</title>
+
+ <p>
+ The best way to get profiles is to generate them yourself, although
+ this does require some initial outlay.
+ </p>
+ <p>
+ Many manufacturers do try to provide color profiles for devices,
+ although sometimes they are wrapped up in <em>driver bundles</em>
+ which you may need to download, extract and then search for the
+ color profiles.
+ </p>
+ <p>
+ Some manufacturers do not provide accurate profiles for the hardware
+ and the profiles are best avoided.
+ A good clue is to download the profile, and if the creation date is
+ more than a year before the date you bought the device then it's
+ likely dummy data generated that is useless.
+ </p>
+
+ <p>
+ See <link xref="color-why-calibrate"/> for information on why vendor
+ suplied profiles are often worse than useless.
+ </p>
+
+</page>
diff --git a/gnome-help/C/color-missingvcgt.page b/gnome-help/C/color-missingvcgt.page
new file mode 100644
index 0000000..5627109
--- /dev/null
+++ b/gnome-help/C/color-missingvcgt.page
@@ -0,0 +1,29 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-missingvcgt">
+
+ <info>
+ <link type="guide" xref="color#problems"/>
+ <link type="seealso" xref="color-gettingprofiles"/>
+ <desc>Whole-screen color correction modifies all the screen colors on all windows.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>Missing information for whole-screen color correction?</title>
+ <p>
+ Unfortunately, many vendor-supplied ICC profiles do not include the
+ information required for whole-screen color correction.
+ These profiles can still be useful for applications that can do color
+ compensation, but you will not see all the colors of your screen change.
+ </p>
+ <p>
+ In order to create a display profile, which includes both calibration and
+ characterisation data, you will need to use a special color measuring
+ instruments callled a colorimeter or a spectrometer.
+ </p>
+
+</page>
diff --git a/gnome-help/C/color-notspecifiededid.page b/gnome-help/C/color-notspecifiededid.page
new file mode 100644
index 0000000..363df91
--- /dev/null
+++ b/gnome-help/C/color-notspecifiededid.page
@@ -0,0 +1,39 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-notspecifiededid">
+
+ <info>
+ <link type="guide" xref="color#problems"/>
+ <link type="guide" xref="color-gettingprofiles"/>
+ <link type="guide" xref="color-why-calibrate"/>
+ <desc>Default monitor profiles do not have a calibration date.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>Why don't the default monitor profiles have a calibration expiry?</title>
+ <p>
+ The default color profile used for each monitor is generated
+ automatically based on the display EDID which is stored in a memory
+ chip inside the monitor.
+ The EDID only gives us a snapshot of the available colors the monitor
+ was capable of displaying when it was manufactured, and does not
+ contain much other information for color correction.
+ </p>
+
+ <figure>
+ <desc>As the EDID cannot be updated, it has no expiry date.</desc>
+ <media type="image" mime="image/png" src="figures/color-profile-default.png"/>
+ </figure>
+
+ <note style="tip">
+ <p>
+ Getting a profile from the monitor vendor or creating a profile
+ youself would lead to more accurate color correction.
+ </p>
+ </note>
+
+</page>
diff --git a/gnome-help/C/color-whatisprofile.page b/gnome-help/C/color-whatisprofile.page
new file mode 100644
index 0000000..90d3360
--- /dev/null
+++ b/gnome-help/C/color-whatisprofile.page
@@ -0,0 +1,39 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-whatisprofile">
+
+ <info>
+ <link type="guide" xref="color#profiles"/>
+ <desc>A color profile is a simple file that expresses a color space or device response.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>What is a color profile?</title>
+
+ <p>
+ A color profile is a set of data that characterizes either a device
+ such as a projector or a color space such as sRGB.
+ </p>
+ <p>
+ Most color profiles are in the form of an ICC profile, which is a
+ small file with a <input>.ICC</input> or <input>.ICM</input> file
+ extension.
+ </p>
+ <p>
+ Color profiles can be embedded into images to specify the gamut range
+ of the data.
+ This ensures that users see the same colors on different devices.
+ </p>
+ <p>
+ Every device that is processing color should have it's own ICC
+ profile and when this is achieved the system is said to have an
+ <em>end-to-end color-managed workflow</em>.
+ With this kind of workflow you can be sure that colors are not being
+ lost or modified.
+ </p>
+
+</page>
diff --git a/gnome-help/C/color-why-calibrate.page b/gnome-help/C/color-why-calibrate.page
new file mode 100644
index 0000000..560a37b
--- /dev/null
+++ b/gnome-help/C/color-why-calibrate.page
@@ -0,0 +1,41 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-why-calibrate">
+
+ <info>
+ <link type="guide" xref="color#calibration"/>
+ <desc>Calibrating is important if you care about the colors you display or print.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>Why do I need to do calibration myself?</title>
+
+ <p>
+ Generic profiles are usually bad.
+ When a manufacturer creates a new model, they just take a few items
+ from the production line and average them together:
+ </p>
+
+ <media type="image" src="figures/color-average.png">
+ <p>Averaged profiles</p>
+ </media>
+
+ <p>
+ Display panels differ quite a lot from unit to unit and change
+ substantially as the display ages.
+ It is also more difficult for printers, as just changing the type
+ or weight of paper can invalidate the characterization state and
+ make the profile inaccurate.
+ </p>
+
+ <p>
+ The best way of ensuring the profile you have is accurate is by doing
+ the calibration yourself, or by letting an external company supply
+ you with a profile based on your exact characterization state.
+ </p>
+
+</page>
diff --git a/gnome-help/C/color-whyimportant.page b/gnome-help/C/color-whyimportant.page
new file mode 100644
index 0000000..5ca8bd4
--- /dev/null
+++ b/gnome-help/C/color-whyimportant.page
@@ -0,0 +1,100 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="topic"
+ id="color-whyimportant">
+
+ <info>
+ <link type="guide" xref="color"/>
+ <desc>Color management is important for designers, photographers and artists.</desc>
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
+ </info>
+
+ <title>Why is color management important?</title>
+ <p>
+ Color management is the process of capturing a color using an input
+ device, displaying it on a screen, and printing it all whilst managing
+ the exact colors and the range of colors on each medium.
+ </p>
+
+ <p>
+ The need for color management is probably explained best with a
+ photograph of a bird on a frosty day in winter.
+ </p>
+
+ <figure>
+ <desc>A bird on a frosty wall as seen on the camera view-finder</desc>
+ <media type="image" mime="image/png" src="figures/color-camera.png"/>
+ </figure>
+
+ <p>
+ Displays typically over-saturate the blue channel, making the images
+ look cold.
+ </p>
+
+ <figure>
+ <desc>This is what the user sees on a typical business laptop screen</desc>
+ <media type="image" mime="image/png" src="figures/color-display.png"/>
+ </figure>
+
+ <p>
+ Notice how the white is not 'paper white' and the black of the eye
+ is now a muddy brown.
+ </p>
+
+ <figure>
+ <desc>This is what the user sees when printing on a typical inkjet printer</desc>
+ <media type="image" mime="image/png" src="figures/color-printer.png"/>
+ </figure>
+
+ <p>
+ The basic problem we have here is that each device is capable of
+ handling a different range of colors.
+ So while you might be able to take a photo of electric blue, most
+ printers are not going to be able to reproduce it.
+ </p>
+ <p>
+ Most image devices capture in RGB (Red, Green, Blue) and have
+ to convert to CMYK (Cyan, Magenta, Yellow, and Black) to print.
+ Another problem is that you can't have <em>white</em> ink, and so
+ the whiteness can only be as good as the paper color.
+ </p>
+
+ <p>
+ Another problem is units.
+ Without specifying the scale on which a color is measured, we don't
+ know if 100% red is near infrared or just the deepest red ink in the
+ printer.
+ What is 50% red on your display is probably something like 62% on my
+ display.
+ It's like telling a person that you've just driven 7 units of
+ distance, without the unit you don't know if that's 7 kilometers or
+ 7 meters.
+ </p>
+
+ <p>
+ In color, we refer to the units as gamut. Gamut is essentually the
+ range of colors that can be reproduced.
+ A device like a DSLR camera might have a very large gamut, being able
+ to capture all the colors in a sunset, but a projector has a very
+ small gamut and all the colors are going to look "washed out".
+ </p>
+
+ <p>
+ In some cases we can <em>correct</em> the device response by altering
+ the data we sent to the device but in other cases where that's not
+ possible (you can't print electric blue) we need to show the user
+ what the result is going to look like.
+ </p>
+
+ <p>
+ For photographs it makes sense to use the full tonal range of a color
+ device, to be able to make smooth changes in color.
+ For other graphics you might want to match the color exactly, which
+ is important if you're trying to print a custom mug with the Red Hat
+ logo, that <em>has</em> to be the exact Red Hat Red.
+ </p>
+
+</page>
diff --git a/gnome-help/C/color.page b/gnome-help/C/color.page
new file mode 100644
index 0000000..4e0a5e5
--- /dev/null
+++ b/gnome-help/C/color.page
@@ -0,0 +1,36 @@
+<page xmlns="http://projectmallard.org/1.0/";
+ type="guide"
+ id="color">
+ <info>
+ <link type="guide" xref="prefs"/>
+ <link type="guide" xref="hardware" />
+
+ <credit type="author">
+ <name>Richard Hughes</name>
+ <email>richard hughsie com</email>
+ </credit>
+ <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"; />
+
+ <desc>
+ <link xref="color-whyimportant">Why is this important</link>,
+ <link xref="color#profiles">Color profiles</link>,
+ <link xref="color#calibration">How to calibrate a device</link>...
+ </desc>
+
+ </info>
+
+ <title>Color management</title>
+
+ <section id="profiles" style="2column">
+ <title>Color profiles</title>
+ </section>
+
+ <section id="calibration" style="2column">
+ <title>Calibration</title>
+ </section>
+
+ <section id="problems" style="2column">
+ <title>Problems</title>
+ </section>
+
+</page>
diff --git a/gnome-help/C/figures/color-average.png b/gnome-help/C/figures/color-average.png
new file mode 100644
index 0000000..102d339
Binary files /dev/null and b/gnome-help/C/figures/color-average.png differ
diff --git a/gnome-help/C/figures/color-camera.png b/gnome-help/C/figures/color-camera.png
new file mode 100644
index 0000000..2c03c2b7
Binary files /dev/null and b/gnome-help/C/figures/color-camera.png differ
diff --git a/gnome-help/C/figures/color-display.png b/gnome-help/C/figures/color-display.png
new file mode 100644
index 0000000..121ed6b
Binary files /dev/null and b/gnome-help/C/figures/color-display.png differ
diff --git a/gnome-help/C/figures/color-printer.png b/gnome-help/C/figures/color-printer.png
new file mode 100644
index 0000000..6a8ffaf
Binary files /dev/null and b/gnome-help/C/figures/color-printer.png differ
diff --git a/gnome-help/C/figures/color-profile-default.png b/gnome-help/C/figures/color-profile-default.png
new file mode 100644
index 0000000..fe5e6a9
Binary files /dev/null and b/gnome-help/C/figures/color-profile-default.png differ
diff --git a/gnome-help/C/hardware.page b/gnome-help/C/hardware.page
index 28783f7..bfda370 100644
--- a/gnome-help/C/hardware.page
+++ b/gnome-help/C/hardware.page
@@ -18,6 +18,7 @@
<link xref="hardware#problems">Hardware problems</link>,
<link xref="printing">printers</link>,
<link xref="power">power settings</link>,
+ <link xref="color">color management</link>,
<link xref="bluetooth">Bluetooth</link>,
<link xref="disk">disks</link>...
</desc>
diff --git a/gnome-help/Makefile.am b/gnome-help/Makefile.am
index 2f1584d..b907eda 100644
--- a/gnome-help/Makefile.am
+++ b/gnome-help/Makefile.am
@@ -5,6 +5,11 @@ HELP_ID = gnome-help
HELP_LINGUAS = ca de fi es gl hi nl sl sv vi
HELP_MEDIA = \
+ figures/color-average.png \
+ figures/color-camera.png \
+ figures/color-display.png \
+ figures/color-printer.png \
+ figures/color-profile-default.png \
figures/gnome.png \
figures/gnome-searchtool.png \
figures/nautilus.png \
@@ -57,6 +62,22 @@ HELP_FILES = \
bluetooth-remove-connection.page \
bluetooth-send-file.page \
bluetooth-turn-on-off.page \
+ color.page \
+ color-assignprofiles.page \
+ color-calibrate-camera.page \
+ color-calibrate-printer.page \
+ color-calibrate-scanner.page \
+ color-calibrate-screen.page \
+ color-calibrationcharacterization.page \
+ color-calibrationdevices.page \
+ color-calibrationtargets.page \
+ color-canshareprofiles.page \
+ color-gettingprofiles.page \
+ color-missingvcgt.page \
+ color-notspecifiededid.page \
+ color-whatisprofile.page \
+ color-why-calibrate.page \
+ color-whyimportant.page \
clock.page \
clock-calendar.page \
clock-set.page \
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