[gimp-help] Fix #223 Update channelmixer and monomixer documentation
- From: Jacob Boerema <jboerema src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gimp-help] Fix #223 Update channelmixer and monomixer documentation
- Date: Sun, 29 May 2022 01:58:07 +0000 (UTC)
commit d582713c7ae8b23d633f07bf6d03026e180a2917
Author: Jacob Boerema <jgboerema gmail com>
Date: Sat May 28 21:56:38 2022 -0400
Fix #223 Update channelmixer and monomixer documentation
Closes #55, #56
images/C/menus/colors/components/channelmixer.png | Bin 54807 -> 27605 bytes
.../menus/colors/components/mono_mixer-dialog.png | Bin 27630 -> 19728 bytes
src/menus/colors/components/channel-mixer.xml | 267 ++++++---------------
src/menus/colors/components/mono-mixer.xml | 60 ++++-
4 files changed, 132 insertions(+), 195 deletions(-)
---
diff --git a/images/C/menus/colors/components/channelmixer.png
b/images/C/menus/colors/components/channelmixer.png
index b771fa19f..d93ebfb36 100644
Binary files a/images/C/menus/colors/components/channelmixer.png and
b/images/C/menus/colors/components/channelmixer.png differ
diff --git a/images/C/menus/colors/components/mono_mixer-dialog.png
b/images/C/menus/colors/components/mono_mixer-dialog.png
index c85b45d8f..794d34b43 100644
Binary files a/images/C/menus/colors/components/mono_mixer-dialog.png and
b/images/C/menus/colors/components/mono_mixer-dialog.png differ
diff --git a/src/menus/colors/components/channel-mixer.xml b/src/menus/colors/components/channel-mixer.xml
index fb48b66bc..9b49d9020 100644
--- a/src/menus/colors/components/channel-mixer.xml
+++ b/src/menus/colors/components/channel-mixer.xml
@@ -41,14 +41,14 @@
</figure>
<para>
This command combines values of the RGB channels. It works with images
- with or without an alpha channel. It has monochrome mode and a preview.
+ with or without an alpha channel.
</para>
</sect3>
<sect3>
<title>Activate the command</title>
<para>
- You can find this command through
+ You can find this command in the menu through
<menuchoice>
<guimenu>Colors</guimenu>
<guisubmenu>Components</guisubmenu>
@@ -70,54 +70,35 @@
</figure>
<variablelist>
<varlistentry>
- <term>Output Channel</term>
+ <term>
+ <guilabel>Presets</guilabel>, <guilabel>Blending Options</guilabel>,
+ <guilabel>Preview</guilabel>, <guilabel>Split view</guilabel>
+ </term>
<listitem>
<para>
- From this menu you select the channel to mix to. Choices are
- Red, Green, or Blue. It is insensitive when
- <guilabel>Monochrome</guilabel> option is checked.
+ These options are common to GEGL-based filters. Please refer to
+ <xref linkend="gimp-filters-common"/>.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term>Red, Green, Blue</term>
+ <term>Red Channel, Green Channel, Blue Channel</term>
<listitem>
<para>
- These three sliders set the contribution of red, green or blue
- channel to output. Can be negative. These sliders are graduated
- from -200 to 200. They represent the percentage which will be
- attributed to the output channel. 100% corresponds to the value of
- the channel of the studied pixel in the image.
+ Each of these has three sliders, which set the contribution of the
+ red, green and blue input channels in the output channel.
+ The sliders go from -2 to 2. They represent the multiplication
+ factor of the input channel that will be attributed to the output
+ channel.
</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term>Monochrome</term>
- <listitem>
- <para>
- This option converts the RGB image into a gray-scale RGB image.
- The Channel Mixer command is often used with this aim in view,
- because it often provides a better result than the other ways
- (see <link linkend="glossary-graylevel">Grayscale</link> in
- Glossary). Makes the <guilabel>Output Channel</guilabel> menu
- insensitive.
- </para>
- <note>
- <para>
- <!--Verified for v2.6-->
- The 21%, 72%, 7% settings give you the same gray luminosity
- (Value) as the Grayscale command in Image/Mode. (They were 30%,
- 59%, 11% in v2.2).
- </para>
- </note>
- </listitem>
- </varlistentry>
<varlistentry>
<term>Preserve Luminosity</term>
<listitem>
<para>
- Calculations may result in too high values and an image too much
- clear. This option lessens luminosities of the color channels
+ The mixing can result in an image where some of the colors are too
+ light. This option lessens the luminosity of the color channels
while keeping a good visual ratio between them. So, you can change
the relative weight of the colors without changing the overall
luminosity.
@@ -127,169 +108,77 @@
</variablelist>
</sect3>
- <sect3>
- <title>Buttons</title>
- <variablelist>
- <varlistentry>
- <term>Open</term>
- <listitem>
- <para>Load settings from a file.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Save</term>
- <listitem>
- <para>Save settings to a file.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Reset</term>
- <listitem>
- <para>Set default settings.</para>
- </listitem>
- </varlistentry>
- </variablelist>
- </sect3>
-
<sect3>
<title>How does Channel Mixer work? </title>
- <variablelist>
- <varlistentry>
- <term>In RGB mode</term>
- <listitem>
+ <para>
+ Each of the output channels is based on the values you set for the three
+ RGB input channels. By default each output channel is based for 100%
+ on the corresponding input channel. This is the one set to 1.0, and the
+ others are set to 0.0. You can change each of the sliders from -2 to +2.
+ </para>
+ <para>
+ The three RGB input sliders let you give a percentage to every channel.
+ For every pixel in the image, the sum of the calculated values for
+ every channel from these percentages will be given to the output
+ channel. Here is an example:
+ </para>
+ <figure>
+ <title>The original image and its channels</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata format="PNG"
+ fileref="images/menus/colors/components/channel-mixer-ex1.png"/>
+ </imageobject>
+ <caption>
<para>
- In this mode, you have to select an <guilabel>Output Channel
- </guilabel>. This channel is the one which will be modified. In
- the dialog window, its default value is 100%, corresponding to
- the value of the channel in the original image. It can be
- increased or decreased. That's why slider ends are -200 and 200.
+ RGB values of the pixels in red, green, blue, gray squares
+ are displayed. The black rectangle is special, because black
+ (0;0;0) is not affected by the command (0 multiplied by any
+ percentage always gives 0). The result can't exceed 255 nor
+ be negative.
</para>
+ </caption>
+ </mediaobject>
+ </figure>
+ <figure>
+ <title>Output channel is red. Green Channel +50</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata format="PNG"
+ fileref="images/menus/colors/components/channel-mixer-ex2.png"/>
+ </imageobject>
+ <caption>
<para>
- Three RGB sliders let you give a percentage to every channel. For
- every pixel in the image, the sum of the calculated values for
- every channel from these percentages will be given to the Output
- Channel. Here is an example:
+ In the red square, the pixel values are 230;10;10. Relative
+ values are 1;0.5;0. The calculation result is 230*1 + 10*0,5
+ + 10*0 =235. The same reasoning is valid for the green and
+ the blue squares.
</para>
- <figure>
- <title>The original image and its channels</title>
- <mediaobject>
- <imageobject>
- <imagedata format="PNG"
- fileref="images/menus/colors/components/channel-mixer-ex1.png"/>
- </imageobject>
- <caption>
- <para>
- RGB values of the pixels in red, green, blue, gray squares
- are displayed. The black rectangle is special, because black
- (0;0;0) is not concerned by the command (0 multiplied by any
- percentage always gives 0). The result can't exceed 255 nor
- be negative.
- </para>
- </caption>
- </mediaobject>
- </figure>
- <figure>
- <title>Output channel is red. Green Channel +50</title>
- <mediaobject>
- <imageobject>
- <imagedata format="PNG"
- fileref="images/menus/colors/components/channel-mixer-ex2.png"/>
- </imageobject>
- <caption>
- <para>
- In the red square, the pixel values are 230;10;10. Relative
- values are 1;0.5;0. The calculation result is 230*1 + 10*0,5
- + 10*0 =235. The same reasoning is valid for the green and
- the blue squares.
- </para>
- <para>
- In the gray square, which contains red color, the
- calculation result is above 255. It is reduced to 255. A
- negative value would be reduced to 0.
- </para>
- </caption>
- </mediaobject>
- </figure>
- <figure>
- <title>
- Output channel is red. Green Channel +50%. The Preserve
- Luminosity option is checked.
- </title>
- <mediaobject>
- <imageobject>
- <imagedata format="PNG"
- fileref="images/menus/colors/components/channel-mixer-ex3.png"/>
- </imageobject>
- <caption>
- <para>
- The values attributed to the Red Output channel are lower,
- preventing a too much clear image.
- </para>
- </caption>
- </mediaobject>
- </figure>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>In Monochrome mode</term>
- <listitem>
<para>
- When this option is checked, the image preview turns to grayscale,
- but the image is still a RGB image with three channels, until the
- command action is validated.
+ In the gray square, which contains red color, the
+ calculation result is above 255. It is reduced to 255. A
+ negative value would be reduced to 0.
</para>
- <figure>
- <title>
- Monochrome option checked. Red: 100% Green: 50% Blue: 0%.
- Preserve Luminosity unchecked.
- </title>
- <mediaobject>
- <imageobject>
- <imagedata format="PNG"
- fileref="images/menus/colors/components/channel-mixer-ex4.png"/>
- </imageobject>
- <caption>
- <para>
- In every square, pixels have been converted into a gray
- level equal to the value of the Red channel in the original
- image (The background has been painted with pink afterwards
- to make all squares visible).
- </para>
- </caption>
- </mediaobject>
- </figure>
+ </caption>
+ </mediaobject>
+ </figure>
+ <figure>
+ <title>
+ Output channel is red. Green Channel +50%. The Preserve
+ Luminosity option is checked.
+ </title>
+ <mediaobject>
+ <imageobject>
+ <imagedata format="PNG"
+ fileref="images/menus/colors/components/channel-mixer-ex3.png"/>
+ </imageobject>
+ <caption>
<para>
- Here is how the <guilabel>Preserve Luminosity</guilabel>
- works in the monochrome mode:
- <quote>
- For example, suppose the sliders were Red:75%, Green:75%,
- Blue:0%. With <guilabel>Monochrome</guilabel> on and the
- <guilabel>Preserve Luminosity</guilabel>
- option off, the resulting picture would be at 75%+75%+0% =150%,
- very bright indeed. A pixel with a value of, say,
- R,G,B=127,100,80 would map to 127*0.75+100*0.75+80*0=170 for
- each channel. With the Preserve Luminosity option on, the
- sliders will be scaled so they always add up to 100%. In this
- example, that scale value is 1/(75%+75%+0%) or 0.667. So the
- pixel values would be about 113. The Preserve Luminosity option
- just assures that the scale values from the sliders always adds
- up to 100%. Of course, strange things happen when any of the
- sliders have large negative values
- </quote>
- (from the plug-in author himself).
+ The values attributed to the Red Output channel are lower,
+ preventing a too bright image.
</para>
- <note>
- <para><emphasis>Which channel will you modify?</emphasis>
- This depends on what you want to do. In principle, the Red
- channel suits contrast modifications well. The Green channel is
- well adapted to details changes and the Blue channel to noise,
- grain changes. You can use the
- <link linkend="plug-in-decompose-registered">Decompose</link>
- command.
- </para>
- </note>
- </listitem>
- </varlistentry>
- </variablelist>
+ </caption>
+ </mediaobject>
+ </figure>
</sect3>
</sect2>
diff --git a/src/menus/colors/components/mono-mixer.xml b/src/menus/colors/components/mono-mixer.xml
index e1f9d18d8..78c8f662a 100644
--- a/src/menus/colors/components/mono-mixer.xml
+++ b/src/menus/colors/components/mono-mixer.xml
@@ -72,8 +72,9 @@
</figure>
<variablelist>
<varlistentry>
- <term><guilabel>Presets</guilabel>, <guilabel>Preview</guilabel>,
- <guilabel>Split view</guilabel></term>
+ <term>
+ <guilabel>Presets</guilabel>, <guilabel>Blending Options</guilabel>,
+ <guilabel>Preview</guilabel>, <guilabel>Split view</guilabel></term>
<listitem>
<para>
These options are common to GEGL-based filters. Please refer to
@@ -85,8 +86,8 @@
<term><guilabel>Preserve luminosity</guilabel></term>
<listitem>
<para>
- Calculations may result in too high values and an image too much
- clear. This option lessens luminosities of the color channels
+ The mixing can result in an image where some of the colors are too
+ light. This option lessens the luminosity of the color channels
while keeping a good visual ratio between them. So, you can change
the relative weight of the colors without changing the overall
luminosity.
@@ -108,9 +109,56 @@
</variablelist>
</sect3>
<sect3>
- <title>Using Channel Mixer</title>
+ <title>Using Mono Mixer</title>
<para>
- TODO
+ When this filter is opened, the image preview turns to grayscale,
+ but the image is still a RGB image with three channels, until the
+ OK button is pressed.
</para>
+ <figure>
+ <title>
+ Red: 100% Green: 50% Blue: 0%. Preserve Luminosity unchecked.
+ </title>
+ <mediaobject>
+ <imageobject>
+ <imagedata format="PNG"
+ fileref="images/menus/colors/components/channel-mixer-ex4.png"/>
+ </imageobject>
+ <caption>
+ <para>
+ In every square, pixels have been converted into a gray
+ level equal to the value of the Red channel in the original
+ image (The background has been painted with pink afterwards
+ to make all squares visible).
+ </para>
+ </caption>
+ </mediaobject>
+ </figure>
+ <para>
+ Here is how the <guilabel>Preserve Luminosity</guilabel>
+ works in the monochrome mode:
+ <quote>For example, suppose the sliders were Red:75%, Green:75%, Blue:0%.
+ With <guilabel>Preserve Luminosity</guilabel> disabled, the resulting
+ picture would be at 75%+75%+0% =150%, very bright indeed. A pixel with a
+ value of, say, R,G,B=127,100,80 would map to 127*0.75+100*0.75+80*0=170
+ for each channel.
+ With <guilabel>Preserve Luminosity</guilabel> enabled, the sliders will
+ be scaled so they always add up to 100%. In this example, that scale
+ value is 1/(75%+75%+0%) or 0.667. So the pixel values would be about 113.
+ The Preserve Luminosity option just assures that the scale values from
+ the sliders always adds up to 100%. Of course, strange things happen when
+ any of the sliders have large negative values.</quote>
+ (from the plug-in author himself).
+ </para>
+ <note>
+ <para><emphasis>Which channel should you modify?</emphasis>
+ This depends on what you want to do. In principle, the Red
+ channel suits contrast modifications well. The Green channel is
+ well adapted to details changes and the Blue channel to noise,
+ grain changes. You can use the
+ <link linkend="plug-in-decompose-registered">Decompose</link>
+ command.
+ </para>
+ </note>
</sect3>
</sect2>
\ No newline at end of file
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