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55<p class="text-center"><a href="distort.php#AffineTransformImage">AffineTransformImage</a> &bull; <a href="distort.php#DistortImage">DistortImage</a> &bull; <a href="distort.php#RotateImage">RotateImage</a> &bull; <a href="distort.php#SparseColorImage">SparseColorImage</a></p>
56
57<h2><a href="http://www.imagemagick.org/api/MagickCore/distort_8c.html" id="AffineTransformImage">AffineTransformImage</a></h2>
58
59<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>
60
61<p>The format of the AffineTransformImage method is:</p>
62
63<pre class="text">
64Image *AffineTransformImage(const Image *image,
65  AffineMatrix *affine_matrix,ExceptionInfo *exception)
66</pre>
67
68<p>A description of each parameter follows:</p>
69
70<dd>
71</dd>
72
73<dd> </dd>
74<dl class="dl-horizontal">
75<dt>image</dt>
76<dd>the image. </dd>
77
78<dd> </dd>
79<dt>affine_matrix</dt>
80<dd>the affine matrix. </dd>
81
82<dd> </dd>
83<dt>exception</dt>
84<dd>return any errors or warnings in this structure. </dd>
85
86<dd>  </dd>
87</dl>
88<h2><a href="http://www.imagemagick.org/api/MagickCore/distort_8c.html" id="DistortImage">DistortImage</a></h2>
89
90<p>DistortImage() distorts an image using various distortion methods, by mapping color lookups of the source image to a new destination image usally of the same size as the source image, unless 'bestfit' is set to true.</p>
91
92<p>If 'bestfit' is enabled, and distortion allows it, the destination image is adjusted to ensure the whole source 'image' will just fit within the final destination image, which will be sized and offset accordingly.  Also in many cases the virtual offset of the source image will be taken into account in the mapping.</p>
93
94<p>If the '-verbose' control option has been set print to standard error the equicelent '-fx' formula with coefficients for the function, if practical.</p>
95
96<p>The format of the DistortImage() method is:</p>
97
98<pre class="text">
99Image *DistortImage(const Image *image,const DistortImageMethod method,
100  const size_t number_arguments,const double *arguments,
101  MagickBooleanType bestfit, ExceptionInfo *exception)
102</pre>
103
104<p>A description of each parameter follows:</p>
105
106<dd>
107</dd>
108
109<dd> </dd>
110<dl class="dl-horizontal">
111<dt>image</dt>
112<dd>the image to be distorted. </dd>
113
114<dd> </dd>
115<dt>method</dt>
116<dd>the method of image distortion. </dd>
117
118<dd> ArcDistortion always ignores source image offset, and always 'bestfit' the destination image with the top left corner offset relative to the polar mapping center. </dd>
119
120<dd> Affine, Perspective, and Bilinear, do least squares fitting of the distrotion when more than the minimum number of control point pairs are provided. </dd>
121
122<dd> Perspective, and Bilinear, fall back to a Affine distortion when less than 4 control point pairs are provided.  While Affine distortions let you use any number of control point pairs, that is Zero pairs is a No-Op (viewport only) distortion, one pair is a translation and two pairs of control points do a scale-rotate-translate, without any shearing. </dd>
123
124<dd> </dd>
125<dt>number_arguments</dt>
126<dd>the number of arguments given. </dd>
127
128<dd> </dd>
129<dt>arguments</dt>
130<dd>an array of floating point arguments for this method. </dd>
131
132<dd> </dd>
133<dt>bestfit</dt>
134<dd>Attempt to 'bestfit' the size of the resulting image. This also forces the resulting image to be a 'layered' virtual canvas image.  Can be overridden using 'distort:viewport' setting. </dd>
135
136<dd> </dd>
137<dt>exception</dt>
138<dd>return any errors or warnings in this structure </dd>
139
140<dd> Extra Controls from Image meta-data (artifacts)... </dd>
141
142<dd> o "verbose" Output to stderr alternatives, internal coefficents, and FX equivalents for the distortion operation (if feasible). This forms an extra check of the distortion method, and allows users access to the internal constants IM calculates for the distortion. </dd>
143
144<dd> o "distort:viewport" Directly set the output image canvas area and offest to use for the resulting image, rather than use the original images canvas, or a calculated 'bestfit' canvas. </dd>
145
146<dd> o "distort:scale" Scale the size of the output canvas by this amount to provide a method of Zooming, and for super-sampling the results. </dd>
147
148<dd> Other settings that can effect results include </dd>
149
150<dd> o 'interpolate' For source image lookups (scale enlargements) </dd>
151
152<dd> o 'filter'      Set filter to use for area-resampling (scale shrinking). Set to 'point' to turn off and use 'interpolate' lookup instead </dd>
153
154<dd>  </dd>
155</dl>
156<h2><a href="http://www.imagemagick.org/api/MagickCore/distort_8c.html" id="RotateImage">RotateImage</a></h2>
157
158<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>
159
160<p>The format of the RotateImage method is:</p>
161
162<pre class="text">
163Image *RotateImage(const Image *image,const double degrees,
164  ExceptionInfo *exception)
165</pre>
166
167<p>A description of each parameter follows.</p>
168
169<dt>image</dt>
170<p>the image.</p>
171
172<dt>degrees</dt>
173<p>Specifies the number of degrees to rotate the image.</p>
174
175<dt>exception</dt>
176<p>return any errors or warnings in this structure.</p>
177
178<h2><a href="http://www.imagemagick.org/api/MagickCore/distort_8c.html" id="SparseColorImage">SparseColorImage</a></h2>
179
180<p>SparseColorImage(), given a set of coordinates, interpolates the colors found at those coordinates, across the whole image, using various methods.</p>
181
182<p>The format of the SparseColorImage() method is:</p>
183
184<pre class="text">
185Image *SparseColorImage(const Image *image,
186  const SparseColorMethod method,const size_t number_arguments,
187  const double *arguments,ExceptionInfo *exception)
188</pre>
189
190<p>A description of each parameter follows:</p>
191
192<dd>
193</dd>
194
195<dd> </dd>
196<dl class="dl-horizontal">
197<dt>image</dt>
198<dd>the image to be filled in. </dd>
199
200<dd> </dd>
201<dt>method</dt>
202<dd>the method to fill in the gradient between the control points. </dd>
203
204<dd> The methods used for SparseColor() are often simular to methods used for DistortImage(), and even share the same code for determination of the function coefficents, though with more dimensions (or resulting values). </dd>
205
206<dd> </dd>
207<dt>number_arguments</dt>
208<dd>the number of arguments given. </dd>
209
210<dd> </dd>
211<dt>arguments</dt>
212<dd>array of floating point arguments for this method-- x,y,color_values-- with color_values given as normalized values. </dd>
213
214<dd> </dd>
215<dt>exception</dt>
216<dd>return any errors or warnings in this structure </dd>
217
218<dd>  </dd>
219</dl>
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