1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>3.4. Selection masks</title>
<link rel="stylesheet" href="gimp-help-plain.css" type="text/css" />
<link rel="stylesheet" href="gimp-help-screen.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.66.1" />
<link rel="start" href="index.html" title=" " />
<link rel="up" href="ch04s03.html" title="3. Channels dialog" />
<link rel="prev" href="ch04s03s03.html" title="3.3. Channels Menu" />
<link rel="next" href="ch04s03s05.html" title="3.5. Quick Mask" />
</head>
<body>
<div xmlns="" class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center" id="chaptername">3.4. Selection masks</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="ch04s03s03.html">Prev</a> </td>
<th width="60%" align="center" id="sectionname">3.4. Selection masks</th>
<td width="20%" align="right"> <a accesskey="n" href="ch04s03s05.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="dialogs-selection-masks"></a>3.4. Selection masks</h3>
</div>
</div>
</div>
<div class="mediaobject">
<img src="../images/dialogs/dialogs-channel-masks.png" />
</div>
<p>
Channels can be used to save and restore your selections. Clicking
on the <span class="guilabel">Quick mask</span> button on the <a href="ch02s03s03.html" title="3.3. Image Window">Image window</a> automatically
creates a new channel called <span class="guilabel">Qmask</span> and saves the
displayed active selection to a thumbail in front of the
channel.There are many selection tools in the Gimp like rectangular
selection tool or fuzzy selection for continuous selections.
Selection Masks are a graphical way to build selections into a gray
level channel where white pixels are selected and black pixels are
not selected. Therefore gray pixels are partially selected. You can
think of them as feathering the selection, a smooth transition
between selected and not selected. This is important to avoid the
ugly pixelization effect when you fill the selection or when you
erase its content after isolating a subject from background.
</p>
<div class="variablelist">
<dl>
<dt>
<span class="term">Creating Selection Masks</span>
</dt>
<dd>
<p>
There are several ways to initialize a selection mask. From the
image window menu
<span class="guimenuitem"><span class="accel">S</span>elect</span>/
<span class="guimenuitem">Save to <span class="accel">C</span>hannel</span> is
available if there is an active selection. From the image window
the bottom-left button creates a <a href="ch04s03s05.html" title="3.5. Quick Mask">Quick
Mask</a>; the content will be initialized with the active
selection. From the channel dialog, when you click on the
<span class="guilabel">New channel</span> button or from the context menu.
</p>
</dd>
</dl>
</div>
<div class="simplesect" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3334113"></a>Using Selectionmasks</h4>
</div>
</div>
</div>
<p>
Once the channel is initialized, selected (highlighted in blue),
visible (eye-icon in the dialog), and displayed as you want
(color and opacity attributes), you can start to work with all
the paint tools. The colors used are important. If you paint
with some color other than white, grey, or black, the color Value
(luminosity) will be used to define a gray (medium, light, or
dark). When your mask is painted, you can transform it to a
selection by clicking on the <span class="guilabel">Channel to
selection</span> button or from the context menu.
</p>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top" width="25">
<img alt="[Tip]" src="../images/tip.png" />
</td>
<th align="left">Tip</th>
</tr>
<tr>
<td colspan="2" align="left" valign="top">
<p>
You can work in selection masks not only with the paint tool
but also with other tools. For instance, you can use the
selection tools to fill areas uniformly with gradients or
patterns. By adding many selection masks in your list you can
easily compose very complex selections. One can say that a
selection mask is to a selection as a layer is to an image.
</p>
</td>
</tr>
</table>
</div>
<div class="caution" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Caution">
<tr>
<td rowspan="2" align="center" valign="top" width="25">
<img alt="[Caution]" src="../images/caution.png" />
</td>
<th align="left">Caution</th>
</tr>
<tr>
<td colspan="2" align="left" valign="top">
<p>
As long as a selection mask is activated you are working in the
mask and not in the image. To work in the image you have to
deactivate all selection masks. Don't forget also to stop
displaying masks in the image by removing the eye icon. Check
also that all RGB and Alpha channels are activated and
displayed in the image.
</p>
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="ch04s03s03.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="ch04s03.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="ch04s03s05.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">3.3. Channels Menu </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> 3.5. Quick Mask</td>
</tr>
</table>
</div>
</body>
</html>
|
