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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
|
<?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>7.4. Mask</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="ch05s07.html" title="7. Layers" />
<link rel="prev" href="ch05s07s03.html" title="7.3. Colors" />
<link rel="next" href="ch05s07s05.html" title="7.5. Transparency" />
</head>
<body>
<div xmlns="" class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center" id="chaptername">7.4. Mask</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="ch05s07s03.html">Prev</a> </td>
<th width="60%" align="center" id="sectionname">7.4. Mask</th>
<td width="20%" align="right"> <a accesskey="n" href="ch05s07s05.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="gimp-layer-mask-menu"></a>7.4. Mask</h3>
</div>
</div>
</div>
<div class="informalfigure">
<div class="mediaobject">
<img src="../images/menus/menus-layer-mask.png" />
<div class="caption">
<p>
The Mask submenu of the Layers menu
</p>
</div>
</div>
</div>
<p>
The Mask submenu of the Layers menu contains operations that
involve a layer mask: creating one, applying one, deleting one,
or converting one into a selection. See the <a href="ch04s02s03.html" title="2.3. Layer masks">Layer Masks</a> section for more
information on layer masks and how to use them.
</p>
<div class="simplesect" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="gimp-layer-mask-add"></a>Add Layer Mask</h4>
</div>
</div>
</div>
<div class="informalfigure">
<div class="mediaobject">
<img src="../images/menus/dialogs-add-layer-mask.png" />
<div class="caption">
<p>
The "Add Layer Mask" dialog
</p>
</div>
</div>
</div>
<p>
This command can be accessed from an image menubar as
<span class="guimenu">Layer</span>-><span class="guisubmenu">Mask</span>-><span class="guimenuitem">Add Layer Mask</span>
or from the pop-menu you get by right clicking on the active layer in
the Layer Dialog.
</p>
<p>
"Add Layer Mask" adds a mask to the layer, bringing up a dialog
in which you can set the initial properties of the mask. If the
layer already has a layer mask, or cannot have one because it
lacks an alpha channel, the menu entry is insensitive. See the
<a href="ch04s02s03.html" title="2.3. Layer masks">Layer Mask</a> section for
more information.
</p>
<p>
The popup dialog allows you six choices for the initial contents
of the layer mask:
</p>
<div class="variablelist">
<dl>
<dt>
<span class="term">White</span>
</dt>
<dd>
<p>
This option will produce full opacity when the layer mask;
that is, it will be as if there were no layer mask.
</p>
</dd>
<dt>
<span class="term">Black</span>
</dt>
<dd>
<p>
This option will produce complete transparency, so that you
will need to paint on the layer mask in order to make any
part of the layer visible.
</p>
</dd>
<dt>
<span class="term">Layer's alpha channel</span>
</dt>
<dd>
<p>
This option will cause the layer mask to
produce the same transparency that is produced by the
layer's alpha channel. Note that the alpha channel itself
will not be altered, so for partially transparent areas, the
transparency will be "squared", as it were.
</p>
</dd>
<dt>
<span class="term">Transfer layer's alpha channel</span>
</dt>
<dd>
<p>
This option does the same thing as the previous option,
except that it also resets the layer's alpha channel to full
opacity. The effect, then, is to transfer the transparency
information from the alpha channel to the layer mask,
leaving the layer with the same appearance as before.
</p>
</dd>
<dt>
<span class="term">Selection</span>
</dt>
<dd>
<p>
This option converts the selection into a layer mask, so
that selected areas are opaque, and unselected areas are
transparent. If any areas are partially selected, toggling
the <a href="ch02s04s02.html" title="4.2. QuickMask">QuickMask
button</a> will help you predict what the effects are
going to be.
</p>
</dd>
<dt>
<span class="term">Grayscale copy of layer</span>
</dt>
<dd>
<p>
This option converts the layer itself into a layer mask. It
is mainly useful when you plan to add new contents to the
layer afterwards.
</p>
</dd>
</dl>
</div>
<p>
When you click on "OK" the mask symbol appears at the right of the
layer thumbnail in the Layer Dialog.
</p>
<p>
If you check "Invert Mask" at the bottom of the dialog, then the
resulting mask is inverted, so that transparent becomes opaque
and vice versa.
</p>
</div>
<div class="simplesect" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="gimp-layer-mask-apply"></a>Apply Layer Mask</h4>
</div>
</div>
</div>
<p>
This command can be accessed from an image menubar as
<span class="guimenu">Layer</span>-><span class="guisubmenu">Mask</span>-><span class="guimenuitem">Apply Layer Mask</span>.
or from the pop-menu you get by right clicking on the active layer in
the Layer Dialog.
</p>
<p>
"Apply Layer Mask" causes the layer mask to be merged with the active
layer, with the transparency set by the mask applied to the
layer's alpha channel. The layer mask is removed. If the
active layer does not have a layer mask, the menu entry is
insensitive. See the
<a href="ch04s02s03.html" title="2.3. Layer masks">Layer Masks</a> section for more
information.
</p>
</div>
<div class="simplesect" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="gimp-layer-mask-delete"></a>Delete Layer Mask</h4>
</div>
</div>
</div>
<p>
This command can be accessed from an image menubar as
<span class="guimenu">Layer</span>-><span class="guisubmenu">Mask</span>-><span class="guimenuitem">Delete Layer Mask</span>
or from the pop-menu you get by right clicking on the active layer in
the Layer Dialog.
</p>
<p>
"Delete Layer Mask" deletes the active layer's layer mask. If
the active
layer does not have one, the menu entry is insensitive.
</p>
</div>
<div class="simplesect" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="gimp-layer-mask-selection-replace"></a>Mask to Selection (or Add; Subtract; Intersect)</h4>
</div>
</div>
</div>
<a id="gimp-layer-mask-selection-add"></a>
<a id="gimp-layer-mask-selection-subtract"></a>
<a id="gimp-layer-mask-selection-intersect"></a>
<p>
These commands can be accessed from an image menubar as
<span class="guimenu">Layer</span>-><span class="guisubmenu">Mask</span>,
followed by <span class="guimenuitem">Mask to Selection</span>,
<span class="guimenuitem">Add to Selection</span>,
<span class="guimenuitem">Subtract from Selection</span>, or
<span class="guimenuitem">Intersection with Selection</span>
or from the pop-menu you get by right clicking on the active layer in
Layer Dialog.
</p>
<p>
"Mask to Selection" transforms the active layer's layer mask
into a selection mask, that is, into the image's selection. White
areas of the mask become completely selected, black areas
unselected, and gray areas partially selected. The other
operations in this group do similar things, except that instead
of completely replacing the existing selection with the
selection produced from the layer mask, they either add the two
selections, subtract the layer mask selection from the existing
selection, or yield a selection that is the intersection of the
two. The mask is not deleted.
</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="ch05s07s03.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="ch05s07.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="ch05s07s05.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">7.3. Colors </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> 7.5. Transparency</td>
</tr>
</table>
</div>
</body>
</html>
|
