libvips-doc 8.4.5-1 / usr / share / gtk-doc / html / libvips / libvips-freqfilt.html

This file is indexed.

/usr/share/gtk-doc/html/libvips/libvips-freqfilt.html is in libvips-doc 8.4.5-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below. 

  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
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>freqfilt: VIPS Reference Manual</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="VIPS Reference Manual">
<link rel="up" href="ch03.html" title="VIPS operation API by section">
<link rel="prev" href="VipsForeignSave.html" title="VipsForeignSave">
<link rel="next" href="libvips-histogram.html" title="histogram">
<meta name="generator" content="GTK-Doc V1.25 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="5"><tr valign="middle">
<td width="100%" align="left" class="shortcuts">
<a href="#" class="shortcut">Top</a><span id="nav_description">  <span class="dim">|</span> 
                  <a href="#libvips-freqfilt.description" class="shortcut">Description</a></span>
</td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td>
<td><a accesskey="u" href="ch03.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="VipsForeignSave.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="libvips-histogram.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="refentry">
<a name="libvips-freqfilt"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="libvips-freqfilt.top_of_page"></a>freqfilt</span></h2>
<p>freqfilt — fourier transforms and frequency-domin filters</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="libvips-freqfilt.stability-level"></a><h2>Stability Level</h2>
<acronym title="The intention of a Stable interface is to enable arbitrary third parties to
develop applications to these interfaces, release them, and have confidence that
they will run on all minor releases of the product (after the one in which the
interface was introduced, and within the same major release). Even at a major
release, incompatible changes are expected to be rare, and to have strong
justifications.
"><span class="acronym">Stable</span></acronym>, unless otherwise indicated
</div>
<div class="refsect1">
<a name="libvips-freqfilt.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="libvips-freqfilt.html#vips-fwfft" title="vips_fwfft ()">vips_fwfft</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="libvips-freqfilt.html#vips-invfft" title="vips_invfft ()">vips_invfft</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="libvips-freqfilt.html#vips-freqmult" title="vips_freqmult ()">vips_freqmult</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="libvips-freqfilt.html#vips-spectrum" title="vips_spectrum ()">vips_spectrum</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="libvips-freqfilt.html#vips-phasecor" title="vips_phasecor ()">vips_phasecor</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="libvips-freqfilt.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;vips/vips.h&gt;
</pre>
</div>
<div class="refsect1">
<a name="libvips-freqfilt.description"></a><h2>Description</h2>
<p>To and from Fourier space, filter in Fourier space, convert Fourier-space
images to a displayable form.</p>
</div>
<div class="refsect1">
<a name="libvips-freqfilt.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="vips-fwfft"></a><h3>vips_fwfft ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_fwfft (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
            <em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
            <em class="parameter"><code>...</code></em>);</pre>
<p>Transform an image to Fourier space.</p>
<p>VIPS uses the fftw Fourier Transform library. If this library was not
available when VIPS was configured, these functions will fail.</p>
<p>See also: <a class="link" href="libvips-freqfilt.html#vips-invfft" title="vips_invfft ()"><code class="function">vips_invfft()</code></a>.</p>
<div class="refsect3">
<a name="vips-fwfft.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>in</p></td>
<td class="parameter_description"><p>input image </p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>out</p></td>
<td class="parameter_description"><p>output image</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>...</p></td>
<td class="parameter_description"><p><code class="literal">NULL</code>-terminated list of optional named arguments</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="vips-fwfft.returns"></a><h4>Returns</h4>
<p> 0 on success, -1 on error.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-invfft"></a><h3>vips_invfft ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_invfft (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
             <em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
             <em class="parameter"><code>...</code></em>);</pre>
<p>Optional arguments:</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><em class="parameter"><code>real</code></em>
: only output the real part</p></li></ul></div>
<p>Transform an image from Fourier space to real space. The result is complex.
If you are OK with a real result, set <em class="parameter"><code>real</code></em>
, it's quicker.</p>
<p>VIPS uses the fftw Fourier Transform library. If this library was not
available when VIPS was configured, these functions will fail.</p>
<p>See also: <a class="link" href="libvips-freqfilt.html#vips-fwfft" title="vips_fwfft ()"><code class="function">vips_fwfft()</code></a>.</p>
<div class="refsect3">
<a name="vips-invfft.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>in</p></td>
<td class="parameter_description"><p>input image </p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>out</p></td>
<td class="parameter_description"><p>output image</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>...</p></td>
<td class="parameter_description"><p><code class="literal">NULL</code>-terminated list of optional named arguments</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="vips-invfft.returns"></a><h4>Returns</h4>
<p> 0 on success, -1 on error.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-freqmult"></a><h3>vips_freqmult ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_freqmult (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
               <em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *mask</code></em>,
               <em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
               <em class="parameter"><code>...</code></em>);</pre>
<p>Multiply <em class="parameter"><code>in</code></em>
 by <em class="parameter"><code>mask</code></em>
 in Fourier space.</p>
<p><em class="parameter"><code>in</code></em>
 is transformed to Fourier space, multipled with <em class="parameter"><code>mask</code></em>
, then
transformed back to real space. If <em class="parameter"><code>in</code></em>
 is already a complex image, just
multiply then inverse transform.</p>
<p>See also: <a class="link" href="libvips-freqfilt.html#vips-invfft" title="vips_invfft ()"><code class="function">vips_invfft()</code></a>, <a class="link" href="libvips-create.html#vips-mask-ideal" title="vips_mask_ideal ()"><code class="function">vips_mask_ideal()</code></a>.</p>
<div class="refsect3">
<a name="vips-freqmult.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>in</p></td>
<td class="parameter_description"><p>input image </p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>mask</p></td>
<td class="parameter_description"><p>mask image</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>out</p></td>
<td class="parameter_description"><p>output image</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>...</p></td>
<td class="parameter_description"><p><code class="literal">NULL</code>-terminated list of optional named arguments</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="vips-freqmult.returns"></a><h4>Returns</h4>
<p> 0 on success, -1 on error.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-spectrum"></a><h3>vips_spectrum ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_spectrum (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
               <em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
               <em class="parameter"><code>...</code></em>);</pre>
<p>Make a displayable (ie. 8-bit unsigned int) power spectrum.</p>
<p>If <em class="parameter"><code>in</code></em>
 is non-complex, it is transformed to Fourier space. Then the
absolute value is passed through <a class="link" href="libvips-conversion.html#vips-scale" title="vips_scale ()"><code class="function">vips_scale()</code></a> in log mode, and <a class="link" href="libvips-conversion.html#vips-wrap" title="vips_wrap ()"><code class="function">vips_wrap()</code></a>.</p>
<p>See also: <a class="link" href="libvips-freqfilt.html#vips-fwfft" title="vips_fwfft ()"><code class="function">vips_fwfft()</code></a>, <a class="link" href="libvips-conversion.html#vips-scale" title="vips_scale ()"><code class="function">vips_scale()</code></a>, <a class="link" href="libvips-conversion.html#vips-wrap" title="vips_wrap ()"><code class="function">vips_wrap()</code></a>.</p>
<div class="refsect3">
<a name="vips-spectrum.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>in</p></td>
<td class="parameter_description"><p>input image </p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>out</p></td>
<td class="parameter_description"><p>output image</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>...</p></td>
<td class="parameter_description"><p><code class="literal">NULL</code>-terminated list of optional named arguments</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="vips-spectrum.returns"></a><h4>Returns</h4>
<p> 0 on success, -1 on error.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-phasecor"></a><h3>vips_phasecor ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_phasecor (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in1</code></em>,
               <em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in2</code></em>,
               <em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
               <em class="parameter"><code>...</code></em>);</pre>
<p>Convert the two input images to Fourier space, calculate phase-correlation,
back to real space.</p>
<p>See also: <a class="link" href="libvips-freqfilt.html#vips-fwfft" title="vips_fwfft ()"><code class="function">vips_fwfft()</code></a>, <a class="link" href="libvips-arithmetic.html#vips-cross-phase" title="vips_cross_phase ()"><code class="function">vips_cross_phase()</code></a>,</p>
<div class="refsect3">
<a name="vips-phasecor.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>in1</p></td>
<td class="parameter_description"><p>first input image</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>in2</p></td>
<td class="parameter_description"><p>second input image</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>out</p></td>
<td class="parameter_description"><p>output image</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>...</p></td>
<td class="parameter_description"><p><code class="literal">NULL</code>-terminated list of optional named arguments</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="vips-phasecor.returns"></a><h4>Returns</h4>
<p> 0 on success, -1 on error.</p>
</div>
</div>
</div>
<div class="refsect1">
<a name="libvips-freqfilt.other_details"></a><h2>Types and Values</h2>
</div>
<div class="refsect1">
<a name="libvips-freqfilt.see-also"></a><h2>See Also</h2>
<a class="link" href="VipsImage.html" title="VipsImage">image</a>
</div>
</div>
<div class="footer">
<hr>Generated by GTK-Doc V1.25</div>
</body>
</html>

APT Browse - Built by Thomas Orozco.