Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / ImageMagick / cd1da08edce989e248041cacf5c280e54ddabdce / . / www / api / shear.html
blob: 1f244531fea43d8cbd09c9be793b92b48ed4422f [file] [log] [blame]
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]1<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
2 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
3<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
4<head>
5 <meta name="verify-v1" content="g222frIIxcQTrvDR3NBRUSKP3AnMNoqxOkIniCEkV7U=" />
6 <link rel="meta" type="application/rdf+xml" title="ICI" href="http://imagemagick.org/ici.rdf" />
7 <style type="text/css" media="screen,projection"><!--
8 @import url("../../www/magick.css");
9 --></style>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]10 <link rel="shortcut icon" href="../../images/wand.ico" type="images/vnd.microsoft.icon"/>
11 <title>ImageMagick: MagickCore, C API for ImageMagick: Shear or Rotate an Image by an Arbitrary Angle</title>
12 <meta http-equiv="Content-Language" content="en-US"/>
13 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
14 <meta http-equiv="Reply-to" content="magick-users@imagemagick.org"/>
15 <meta name="Generator" content="PHP"/>
16 <meta name="Keywords" content="magickcore, c, api, for, imagemagick:, shear, or, rotate, an, image, by, an, arbitrary, angle, ImageMagick, ImageMagic, MagickCore, MagickWand, PerlMagick, Magick++, RMagick, PythonMagick, JMagick, TclMagick, Image, Magick, Magic, Wand, ImageMagickObject, Swiss, Army, Knife, Image, Processing"/>
17 <meta name="Description" content="ImageMagick® is a software suite to create, edit, and compose bitmap images. It can read, convert and write images in a variety of formats (about 100) including GIF, JPEG, JPEG-2000, PNG, PDF, PhotoCD, TIFF, and DPX. Use ImageMagick to translate, flip, mirror, rotate, scale, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves. ImageMagick is free software delivered as a ready-to-run binary distribution or as source code that you can freely use, copy, modify, and distribute. Its license is compatible with the GPL. It runs on all major operating systems. The functionality of ImageMagick is typically utilized from the command line or you can use the features from programs written in your favorite programming language. Choose from these interfaces: MagickCore (C), MagickWand (C), ChMagick (Ch), Magick++ (C++), JMagick (Java), L-Magick (Lisp), PascalMagick (Pascal), PerlMagick (Perl), MagickWand for PHP (PHP), PythonMagick (Python), RMagick (Ruby), or TclMagick (Tcl/TK). With a language interface, use ImageMagick to modify or create images automagically and dynamically."/>
18 <meta name="Rating" content="GENERAL"/>
19 <meta name="Robots" content="INDEX, FOLLOW"/>
20 <meta name="Generator" content="ImageMagick Studio LLC"/>
21 <meta name="Author" content="ImageMagick Studio LLC"/>
22 <meta name="Revisit-after" content="2 DAYS"/>
23 <meta name="Resource-type" content="document"/>
24 <meta name="Copyright" content="Copyright (c) 1999-2009 ImageMagick Studio LLC"/>
25 <meta name="Distribution" content="Global"/>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]26</head>
27
28<body id="www-imagemagick-org">
29<div class="titlebar">
30<a href="../../index.html">
31 <img src="../../images/script.png" alt="[ImageMagick]"
32 style="width: 350px; height: 60px; margin: 28px auto; float: left;" /></a>
33<a href="http://www.networkredux.com">
34 <img src="../../images/networkredux.png" alt="[sponsor]"
35 style="margin: 45px auto; border: 0px; float: left;" /></a>
36<a href="http://www.imagemagick.org/discourse-server/">
37 <img src="../../images/logo.jpg" alt=""
38 style="width: 114px; height: 118px; border: 0px; float: right;" /></a>
39<a href="../../index.html">
40 <img src="../../images/sprite.jpg" alt=""
41 style="width: 114px; height: 118px; border: 0px; float: right;" /></a>
42</div>
43
44<div class="eastbar">
45
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]46<div class="menu">
47 <a href="../../index.html">About ImageMagick</a>
48</div>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]49<div class="sep"></div>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]50<div class="menu">
51 <a href="../../www/command-line-tools.html">Command-line Tools</a>
52</div>
53<div class="sub">
54 <a href="../../www/command-line-processing.html">Processing</a>
55</div>
56<div class="sub">
57 <a href="../../www/command-line-options.html">Options</a>
58</div>
59<div class="sub">
60 <a href="http://www.imagemagick.org/Usage/">Usage</a>
61</div>
62<div class="menu">
63 <a href="../../www/api.html">Program Interfaces</a>
64</div>
65<div class="sub">
66 <a href="../../www/magick-wand.html">MagickWand</a>
67</div>
68<div class="sub">
69 <a href="../../www/magick-core.html">MagickCore</a>
70</div>
71<div class="sub">
72 <a href="../../www/perl-magick.html">PerlMagick</a>
73</div>
74<div class="sub">
75 <a href="../../Magick++/">Magick++</a>
76</div>
77<div class="menu">
78 <a href="../../www/architecture.html">Architecture</a>
79</div>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]80<div class="sep"></div>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]81<div class="menu">
82 <a href="../../www/install-source.html">Install from Source</a>
83</div>
84<div class="sub">
85 <a href="../../www/install-source.html#unix">Unix</a>
86</div>
87<div class="sub">
88 <a href="../../www/install-source.html#windows">Windows</a>
89 </div>
90<div class="menu">
91 <a href="../../www/binary-releases.html">Binary Releases</a>
92</div>
93<div class="sub">
94 <a href="../../www/binary-releases.html#unix">Unix</a>
95</div>
96<div class="sub">
97 <a href="../../www/binary-releases.html#macosx">Mac OS X</a>
98</div>
99<div class="sub">
100 <a href="../../www/binary-releases.html#windows">Windows</a>
101</div>
102<div class="menu">
103 <a href="../../www/resources.html">Resources</a>
104</div>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]105<div class="sep"></div>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]106<div class="menu">
107 <a href="../../www/download.html">Download</a>
108</div>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]109<div class="sep"></div>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]110<div class="menu">
111 <a href="../http://www.imagemagick.org/script/search.php">Search</a>
112</div>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]113<div class="sep"></div>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]114<div class="menu">
115 <a href="../../www/sitemap.html">Site Map</a>
116</div>
117<div class="sub">
118 <a href="../../www/links.html">Links</a>
119</div>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]120<div class="sep"></div>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]121<div class="menu">
122 <a href="../../www/sponsors.html">Sponsors:</a>
123
124<div class="sponsbox">
125<div class="sponsor">
cristycd1da082009-11-11 02:24:40 +0000[diff] [blame^]126 <a href="http://www.hygi.de">Reinigungsmittel</a><!-- 201002000400+ -->
127</div>
128<div class="sponsor">
cristy0f61e612009-11-10 20:03:57 +0000[diff] [blame]129 <a href="http://www.online-kredit-index.de">Kredit</a><!-- 201004010120 Buchhorn -->
cristy2744bd92009-11-08 22:57:52 +0000[diff] [blame]130</div>
131<div class="sponsor">
132 <a href="http://www.blumenversender.com">Blumenversand</a><!-- 201005010120 -->
cristyc1c61662009-09-30 14:04:37 +0000[diff] [blame]133</div>
134<div class="sponsor">
cristyb4c03bb2009-09-27 13:55:46 +0000[diff] [blame]135 <a href="http://www.print24.de/">Druckerei</a><!-- 201009010720 -->
136</div>
137<div class="sponsor">
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]138 <a href="http://www.goyax.de">Börse</a><!-- 201001000240 Gewiese digital-finance.de -->
139</div>
140<div class="sponsor">
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]141 <a href="http://www.allesdruck.de">Druckerei Online</a><!-- 201012001200 allesdruck.de-->
142</div>
143<div class="sponsor">
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]144 <a href="http://www.who-sells-it.com/">Free Catalogs</a><!-- 201002010000 -->
145</div>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]146</div>
147</div>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]148
149
150</div>
151
152<div class="main">
153
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]154<p class="navigation-index">[<a href="#AffineTransformImage">AffineTransformImage</a> &bull; <a href="#DeskewImage">DeskewImage</a> &bull; <a href="#RotateImage">RotateImage</a> &bull; <a href="#ShearImage">ShearImage</a>]</p>
155
156<h2><a href="http://www.imagemagick.org/api/MagickCore/shear
157_8c.html" target="source" name="AffineTransformImage">AffineTransformImage</a></h2>
158<div class="doc-section">
159
160<p>AffineTransformImage() transforms an image as dictated by the affine matrix. It allocates the memory necessary for the new Image structure and returns a pointer to the new image.</p></ol>
161
162<p>The format of the AffineTransformImage method is:</p>
163
164<pre class="code">
165 Image *AffineTransformImage(const Image *image,
166 AffineMatrix *affine_matrix,ExceptionInfo *exception)
167</pre>
168
169<p>A description of each parameter follows:</p></ol>
170
171<h5>image</h5>
172<ol><p>the image.</p></ol>
173
174<h5>affine_matrix</h5>
175<ol><p>the affine matrix.</p></ol>
176
177<h5>exception</h5>
178<ol><p>return any errors or warnings in this structure.</p></ol>
179
180 </div>
181<h2><a href="http://www.imagemagick.org/api/MagickCore/shear
182_8c.html" target="source" name="DeskewImage">DeskewImage</a></h2>
183<div class="doc-section">
184
185<p>DeskewImage() removes skew from the image. Skew is an artifact that occurs in scanned images because of the camera being misaligned, imperfections in the scanning or surface, or simply because the paper was not placed completely flat when scanned.</p></ol>
186
187<p>The format of the DeskewImage method is:</p>
188
189<pre class="code">
190 Image *DeskewImage(const Image *image,const double threshold,
191 ExceptionInfo *exception)
192</pre>
193
194<p>A description of each parameter follows:</p></ol>
195
196<h5>image</h5>
197<ol><p>the image.</p></ol>
198
199<h5>threshold</h5>
200<ol><p>separate background from foreground.</p></ol>
201
202<h5>exception</h5>
203<ol><p>return any errors or warnings in this structure.</p></ol>
204
205 </div>
206<h2><a href="http://www.imagemagick.org/api/MagickCore/shear
207_8c.html" target="source" name="RotateImage">RotateImage</a></h2>
208<div class="doc-section">
209
210<p>RotateImage() creates a new image that is a rotated copy of an existing one. Positive angles rotate counter-clockwise (right-hand rule), while negative angles rotate clockwise. Rotated images are usually larger than the originals and have 'empty' triangular corners. X axis. Empty triangles left over from shearing the image are filled with the background color defined by member 'background_color' of the image. RotateImage allocates the memory necessary for the new Image structure and returns a pointer to the new image.</p></ol>
211
212<p>RotateImage() is based on the paper "A Fast Algorithm for General Raster Rotatation" by Alan W. Paeth. RotateImage is adapted from a similar method based on the Paeth paper written by Michael Halle of the Spatial Imaging Group, MIT Media Lab.</p></ol>
213
214<p>The format of the RotateImage method is:</p>
215
216<pre class="code">
217 Image *RotateImage(const Image *image,const double degrees,
218 ExceptionInfo *exception)
219</pre>
220
221<p>A description of each parameter follows.</p></ol>
222
223<h5>image</h5>
224<ol><p>the image.</p></ol>
225
226<h5>degrees</h5>
227<ol><p>Specifies the number of degrees to rotate the image.</p></ol>
228
229<h5>exception</h5>
230<ol><p>return any errors or warnings in this structure.</p></ol>
231
232 </div>
233<h2><a href="http://www.imagemagick.org/api/MagickCore/shear
234_8c.html" target="source" name="ShearImage">ShearImage</a></h2>
235<div class="doc-section">
236
237<p>ShearImage() creates a new image that is a shear_image copy of an existing one. Shearing slides one edge of an image along the X or Y axis, creating a parallelogram. An X direction shear slides an edge along the X axis, while a Y direction shear slides an edge along the Y axis. The amount of the shear is controlled by a shear angle. For X direction shears, x_shear is measured relative to the Y axis, and similarly, for Y direction shears y_shear is measured relative to the X axis. Empty triangles left over from shearing the image are filled with the background color defined by member 'background_color' of the image.. ShearImage() allocates the memory necessary for the new Image structure and returns a pointer to the new image.</p></ol>
238
239<p>ShearImage() is based on the paper "A Fast Algorithm for General Raster Rotatation" by Alan W. Paeth.</p></ol>
240
241<p>The format of the ShearImage method is:</p>
242
243<pre class="code">
244 Image *ShearImage(const Image *image,const double x_shear,
245 const double y_shear,ExceptionInfo *exception)
246</pre>
247
248<p>A description of each parameter follows.</p></ol>
249
250<h5>image</h5>
251<ol><p>the image.</p></ol>
252
253<h5>x_shear, y_shear</h5>
254<ol><p>Specifies the number of degrees to shear the image.</p></ol>
255
256<h5>exception</h5>
257<ol><p>return any errors or warnings in this structure.</p></ol>
258
259 </div>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]260
261</div>
262
263<div id="linkbar">
264 <!-- <span id="linkbar-west">&nbsp;</span> -->
265 <span id="linkbar-center">
266 <a href="http://www.imagemagick.org/discourse-server/">Discourse Server</a> &bull;
267 <a href="../../www/mailing-list.html">Mailing Lists</a> &bull;
cristycd1da082009-11-11 02:24:40 +0000[diff] [blame^]268 <a href="http://studio.webbyland.com/ImageMagick/MagickStudio/scripts/MagickStudio.cgi">Studio</a>
cristyf3bb4782009-09-08 13:10:04 +0000[diff] [blame]269 </span>
270 <span id="linkbar-east">&nbsp;</span>
271 </div>
272 <div class="footer">
273 <span id="footer-west">&copy; 1999-2009 ImageMagick Studio LLC</span>
274 <span id="footer-east"> <a href="../http://www.imagemagick.org/script/contact.php">Contact the Wizards</a></span>
275 </div>
276 <div style="clear: both; margin: 0; width: 100%; "></div>
277</body>
278</html>