[gnome-user-docs] color: fixes and improvements to color management related section of the help

[Alexandre Prokoudine <aprokoudine src gnome org>]

commit ac8f05f23a9afef75e1e573e2f424309c37dc6ff
Author: Alexandre Prokoudine <alexandre prokoudine gmail com>
Date:   Fri Sep 23 07:04:18 2011 +0400

    color: fixes and improvements to color management related section of the help

 gnome-help/C/color-calibrationdevices.page |   21 ++++++++++++++++++---
 gnome-help/C/color-canshareprofiles.page   |    2 +-
 gnome-help/C/color-whyimportant.page       |   28 +++++++++++++++-------------
 3 files changed, 34 insertions(+), 17 deletions(-)
---
diff --git a/gnome-help/C/color-calibrationdevices.page b/gnome-help/C/color-calibrationdevices.page
index 9dfa442..193e2ca 100644
--- a/gnome-help/C/color-calibrationdevices.page
+++ b/gnome-help/C/color-calibrationdevices.page
@@ -6,7 +6,7 @@
 
     <link type="guide" xref="color#calibration"/>
 
-    <desc>We support a huge number of calibration devices.</desc>
+    <desc>We support a large number of calibration devices.</desc>
 
     <credit type="author">
       <name>Richard Hughes</name>
@@ -18,8 +18,9 @@
   <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:
+    GNOME relies on the Argyll color management system to support 
+    color instruments. Thus the following display measuring instruments 
+    are supported:
   </p>
 
   <list>
@@ -40,4 +41,18 @@
    <p>The Pantone Huey is currently the cheapest and best supported hardware in Linux.</p>
   </note>
 
+  <p>
+    Thanks to Argyll there's also a number of spot and strip reading 
+    reflective spectrometers supported to help you calibrating and 
+    characterizing your printers:
+  </p>
+
+  <list>
+    <item><p>X-Rite DTP20 "Pulse" ("swipe" type reflective spectrometer)</p></item>
+    <item><p>X-Rite DTP22 Digital Swatchbook (spot type reflective spectrometer)</p></item>
+    <item><p>X-Rite DTP41 (spot and strip reading reflective spectrometer)</p></item>
+    <item><p>X-Rite DTP41T (spot and strip reading reflective spectrometer)</p></item>
+    <item><p>X-Rite DTP51 (spot reading reflective spectrometer)</p></item>
+  </list>
+
 </page>
diff --git a/gnome-help/C/color-canshareprofiles.page b/gnome-help/C/color-canshareprofiles.page
index bd9b38c..653f721 100644
--- a/gnome-help/C/color-canshareprofiles.page
+++ b/gnome-help/C/color-canshareprofiles.page
@@ -18,7 +18,7 @@
   <p>
     Color profiles that you have created yourself are specific to the
     hardware and lighting conditions that you calibrated for.
-    My DreamColor LP2480zx has been powered for a few hundred hours, and
+    A display that 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>
diff --git a/gnome-help/C/color-whyimportant.page b/gnome-help/C/color-whyimportant.page
index 79010fa..266f47a 100644
--- a/gnome-help/C/color-whyimportant.page
+++ b/gnome-help/C/color-whyimportant.page
@@ -63,12 +63,10 @@
   </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.
+    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 one 
+    display is probably something like 62% on another 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.
@@ -83,18 +81,22 @@
   </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
+    In some cases we can <em>correct</em> the device output by altering
+    the data we sent to it, 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.
+    For photographs it makes sense allowing a relative shift of all 
+    colors to match color reproduction capabilities of a display or a 
+    printer, therefore you need to be able to access full tonal range of 
+    that display or printer. For other graphics such as logos you simply 
+    don't use the full tonal range, you only need few colors matching as 
+    closely as possible, so 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. The 
+    method of transferring colors from one tonal range to another is 
+    usually called gamut mapping.
   </p>
 
 </page>