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+++ b/doc/ColorManagement.html
@@ -1,7 +1,7 @@
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
- <meta content="text/html; charset=ISO-8859-1"
+ <meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
<title>Color Management</title>
<meta content="Graeme W. Gill" name="author">
@@ -30,8 +30,8 @@
with the interaction of human vision and devices, allowing for such
fundamental vision characteristics as white point adaptation and
other phenomena. It should also allow the human end purposes to
- influence the choice between&nbsp; tradeoffs in dealing with
- practical device limitations.<br>
+ influence the choice of&nbsp; tradeoffs in dealing with practical
+ device limitations.<br>
<br>
The key means of implementing color management is to have a way of
relating what we see, to the numbers that each device uses to
@@ -40,13 +40,14 @@
The human eye is known to have 3 type of receptors responsible for
color vision, the long, medium and short wavelength receptors.
Because there are 3 receptors, human color perception is a 3
- dimensional phenomena, and therefore at least 3 channels are
- necessary when communicating color information. Any device capable
- of sensing or reproducing color must therefore have at least 3
- channels, and any numerical representation of a full range of colors
- must have at least 3 components and hence may be interpreted as a
- point in a 3 dimensional space. Such a representation is referred to
- as a <span style="font-weight: bold;">Color Space</span>. <br>
+ dimensional phenomena, and therefore at least 3 information channels
+ are necessary when communicating color information. Any device
+ capable of sensing or reproducing color must therefore have at least
+ 3 channels, and any numerical representation of a full range of
+ colors must have at least 3 components and hence may be interpreted
+ as a point in a 3 dimensional space. Such a representation is
+ referred to as a <span style="font-weight: bold;">Color Space</span>.
+ <br>
<br>
Typically color capture and output devices expose their native color
spaces in their hardware interfaces. The native color space is
@@ -69,13 +70,13 @@
style="font-weight: bold;">CMYK</span>). This is because a Cyan
filters out Red wavelengths, Magenta filters out Green wavelengths,
and Yellow filters out Blue wavelengths, allowing these colorants to
- independently control how much RGB is emitted. Because it's
- impossible to make filters that perfectly block C, M or Y
- wavelengths without overlapping each other, C+M+Y filters together
- tend to let some light through, making for an imperfect black.
- Augmenting with an additional Black filter allows improving Black,
- but the extra channel greatly complicates the choice of values to
- create any particular color. <br>
+ independently control how much RGB is reflected or transmitted.
+ Because it's impossible to make filters that perfectly block C, M or
+ Y wavelengths without overlapping each other, C+M+Y filters together
+ tend to let some light from broadband light sources through, making
+ for an imperfect black. Augmenting with an additional Black filter
+ allows improving Black, but the extra channel greatly complicates
+ the choice of colorant values to create any particular color. <br>
<br>
Many color devices have mechanisms for changing the way they respond
to or reproduce color, and such features are called <span
@@ -133,9 +134,8 @@
style="font-weight: bold;">Named</span> profiles represent color <span
style="text-decoration: underline;">anchor points</span>. <span
style="font-weight: bold;">Device Link</span> and <span
- style="font-weight: bold;">Abstract</span> profiles represent <span
- style="text-decoration: underline;">journeys</span> between anchor
- points.<br>
+ style="font-weight: bold;">Abstract</span> profiles represent <u>connections</u>
+ or journeys between anchor points.<br>
<br>
<span style="font-weight: bold;">Device</span><br>
<br>
@@ -184,9 +184,8 @@
Two basic models can be used in ICC profiles, a <span
style="font-weight: bold;">Matrix/shaper</span> model and a <span
style="font-weight: bold;">cLUT</span> (Color Lookup Table) model.
- Models often contain several optional processing elements that are
- applied one after the other in order to provide an overall
- transformation. <br>
+ Models often contain several processing elements that are applied
+ one after the other in order to provide an overall transformation. <br>
<br>
The Matrix/Shaper model consists of a set of per channel lookup
curves followed by a 3x3 matrix. The curves may be defined as a
@@ -234,8 +233,8 @@
common white point (D50), to facilitate ease of matching colors
amongst devices with different white points. Other viewing condition
effects (ie. image luminance level, viewing surround luminance and
- flare/glare) can be modeled using (for example) using CIECAM02 to
- modify XYZ values.<br>
+ flare/glare) can be modeled using (for example) CIECAM02 to modify
+ XYZ values.<br>
<br>
Another limitation relates to spectral assumptions. CIE XYZ uses a
Standard Observer to convert spectral light values into XYZ values,