• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1
2
3
4
5<!DOCTYPE html>
6<html lang="en">
7<head>
8  <meta charset="utf-8"  />
9  <meta name="viewport" content="width=device-width,minimum-scale=1,initial-scale=1,shrink-to-fit=no"  />
10  <title>MagickCore, C API: Morphological Erosions, Dilations, Openings, and Closings @ ImageMagick</title>
11  <meta name="application-name" content="ImageMagick" />
12  <meta name="description" content="Use ImageMagick® to create, edit, compose, or convert bitmap images. You can resize your image, crop it, change its shades and colors, add captions, among other operations." />
13  <meta name="application-url" content="https://imagemagick.org" />
14  <meta name="generator" content="PHP" />
15  <meta name="keywords" content="magickcore, c, api:, morphological, erosions, dilations, openings, closings, ImageMagick, PerlMagick, image processing, image, photo, software, Magick++, OpenMP, convert" />
16  <meta name="rating" content="GENERAL" />
17  <meta name="robots" content="INDEX, FOLLOW" />
18  <meta name="generator" content="ImageMagick Studio LLC" />
19  <meta name="author" content="ImageMagick Studio LLC" />
20  <meta name="revisit-after" content="2 DAYS" />
21  <meta name="resource-type" content="document" />
22  <meta name="copyright" content="Copyright (c) 1999-2017 ImageMagick Studio LLC" />
23  <meta name="distribution" content="Global" />
24  <meta name="magick-serial" content="P131-S030410-R485315270133-P82224-A6668-G1245-1" />
25  <meta name="google-site-verification" content="_bMOCDpkx9ZAzBwb2kF3PRHbfUUdFj2uO8Jd1AXArz4" />
26  <link href="morphology.html" rel="canonical" />
27  <link href="../../images/wand.png" rel="icon" />
28  <link href="../../images/wand.ico" rel="shortcut icon" />
29  <link href="../assets/magick.css" rel="stylesheet" />
30</head>
31<body>
32  <header>
33  <nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
34    <a class="navbar-brand" href="../../"><img class="d-block" id="icon" alt="ImageMagick" width="32" height="32" src="../../images/wand.ico"/></a>
35    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsMagick" aria-controls="navbarsMagick" aria-expanded="false" aria-label="Toggle navigation">
36      <span class="navbar-toggler-icon"></span>
37    </button>
38
39    <div class="navbar-collapse collapse" id="navbarsMagick" style="">
40    <ul class="navbar-nav mr-auto">
41      <li class="nav-item ">
42        <a class="nav-link" href="quantize.html">Home <span class="sr-only">(current)</span></a>
43      </li>
44      <li class="nav-item ">
45        <a class="nav-link" href="../../www/download.html">Download</a>
46      </li>
47      <li class="nav-item ">
48        <a class="nav-link" href="../../www/command-line-tools.html">Tools</a>
49      </li>
50      <li class="nav-item ">
51        <a class="nav-link" href="../../www/command-line-processing.html">Command-line</a>
52      </li>
53      <li class="nav-item ">
54        <a class="nav-link" href="../../www/resources.html">Resources</a>
55      </li>
56      <li class="nav-item ">
57        <a class="nav-link" href="../../www/develop.html">Develop</a>
58      </li>
59      <li class="nav-item">
60        <a class="nav-link" target="_blank" href="https://imagemagick.org/discourse-server/">Community</a>
61      </li>
62    </ul>
63    <form class="form-inline my-2 my-lg-0" action="https://imagemagick.org/script/search.php">
64      <input class="form-control mr-sm-2" type="text" name="q" placeholder="Search" aria-label="Search">
65      <button class="btn btn-outline-success my-2 my-sm-0" type="submit" name="sa">Search</button>
66    </form>
67    </div>
68  </nav>
69  <div class="container">
70   <script async="async" src="https://localhost/pagead/js/adsbygoogle.js"></script>    <ins class="adsbygoogle"
71         style="display:block"
72         data-ad-client="ca-pub-3129977114552745"
73         data-ad-slot="6345125851"
74         data-ad-format="auto"></ins>
75    <script>
76      (adsbygoogle = window.adsbygoogle || []).push({});
77    </script>
78
79  </div>
80  </header>
81  <main class="container">
82    <div class="magick-template">
83<div class="magick-header">
84<p class="text-center"><a href="morphology.html#AcquireKernelInfo">AcquireKernelInfo</a> &#8226; <a href="morphology.html#AcquireKernelBuiltIn">AcquireKernelBuiltIn</a> &#8226; <a href="morphology.html#CloneKernelInfo">CloneKernelInfo</a> &#8226; <a href="morphology.html#DestroyKernelInfo">DestroyKernelInfo</a> &#8226; <a href="morphology.html#MorphologyApply">MorphologyApply</a> &#8226; <a href="morphology.html#This is almost identical to the MorphologyPrimative">This is almost identical to the MorphologyPrimative</a> &#8226; <a href="morphology.html#MorphologyImage">MorphologyImage</a> &#8226; <a href="morphology.html#ScaleGeometryKernelInfo">ScaleGeometryKernelInfo</a> &#8226; <a href="morphology.html#ScaleKernelInfo">ScaleKernelInfo</a> &#8226; <a href="morphology.html#ShowKernelInfo">ShowKernelInfo</a> &#8226; <a href="morphology.html#UnityAddKernelInfo">UnityAddKernelInfo</a> &#8226; <a href="morphology.html#ZeroKernelNans">ZeroKernelNans</a></p>
85
86<h2><a href="../../api/MagickCore/morphology_8c.html" id="AcquireKernelInfo">AcquireKernelInfo</a></h2>
87
88<p>AcquireKernelInfo() takes the given string (generally supplied by the user) and converts it into a Morphology/Convolution Kernel.  This allows users to specify a kernel from a number of pre-defined kernels, or to fully specify their own kernel for a specific Convolution or Morphology Operation.</p>
89
90<p>The kernel so generated can be any rectangular array of floating point values (doubles) with the 'control point' or 'pixel being affected' anywhere within that array of values.</p>
91
92<p>Previously IM was restricted to a square of odd size using the exact center as origin, this is no longer the case, and any rectangular kernel with any value being declared the origin. This in turn allows the use of highly asymmetrical kernels.</p>
93
94<p>The floating point values in the kernel can also include a special value known as 'nan' or 'not a number' to indicate that this value is not part of the kernel array. This allows you to shaped the kernel within its rectangular area. That is 'nan' values provide a 'mask' for the kernel shape.  However at least one non-nan value must be provided for correct working of a kernel.</p>
95
96<p>The returned kernel should be freed using the DestroyKernelInfo() when you are finished with it.  Do not free this memory yourself.</p>
97
98<p>Input kernel defintion strings can consist of any of three types.</p>
99
100<p>"name:args[[@&gt;&lt;]" Select from one of the built in kernels, using the name and geometry arguments supplied.  See AcquireKernelBuiltIn()</p>
101
102<p>"WxH[+X+Y][@&gt;&lt;]:num, num, num ..." a kernel of size W by H, with W*H floating point numbers following. the 'center' can be optionally be defined at +X+Y (such that +0+0 is top left corner). If not defined the pixel in the center, for odd sizes, or to the immediate top or left of center for even sizes is automatically selected.</p>
103
104<p>"num, num, num, num, ..." list of floating point numbers defining an 'old style' odd sized square kernel.  At least 9 values should be provided for a 3x3 square kernel, 25 for a 5x5 square kernel, 49 for 7x7, etc. Values can be space or comma separated.  This is not recommended.</p>
105
106<p>You can define a 'list of kernels' which can be used by some morphology operators A list is defined as a semi-colon separated list kernels.</p>
107
108<p>" kernel ; kernel ; kernel ; "</p>
109
110<p>Any extra ';' characters, at start, end or between kernel defintions are simply ignored.</p>
111
112<p>The special flags will expand a single kernel, into a list of rotated kernels. A '@' flag will expand a 3x3 kernel into a list of 45-degree cyclic rotations, while a '&gt;' will generate a list of 90-degree rotations. The '&lt;' also exands using 90-degree rotates, but giving a 180-degree reflected kernel before the +/- 90-degree rotations, which can be important for Thinning operations.</p>
113
114<p>Note that 'name' kernels will start with an alphabetic character while the new kernel specification has a ':' character in its specification string. If neither is the case, it is assumed an old style of a simple list of numbers generating a odd-sized square kernel has been given.</p>
115
116<p>The format of the AcquireKernal method is:</p>
117
118<pre class="text">
119KernelInfo *AcquireKernelInfo(const char *kernel_string)
120</pre>
121
122<p>A description of each parameter follows:</p>
123
124<dd>
125</dd>
126
127<dd> </dd>
128<dl class="dl-horizontal">
129<dt>kernel_string</dt>
130<dd>the Morphology/Convolution kernel wanted. </dd>
131
132<dd>  </dd>
133</dl>
134<h2><a href="../../api/MagickCore/morphology_8c.html" id="AcquireKernelBuiltIn">AcquireKernelBuiltIn</a></h2>
135
136<p>AcquireKernelBuiltIn() returned one of the 'named' built-in types of kernels used for special purposes such as gaussian blurring, skeleton pruning, and edge distance determination.</p>
137
138<p>They take a KernelType, and a set of geometry style arguments, which were typically decoded from a user supplied string, or from a more complex Morphology Method that was requested.</p>
139
140<p>The format of the AcquireKernalBuiltIn method is:</p>
141
142<pre class="text">
143KernelInfo *AcquireKernelBuiltIn(const KernelInfoType type,
144     const GeometryInfo args)
145</pre>
146
147<p>A description of each parameter follows:</p>
148
149<dd>
150</dd>
151
152<dd> </dd>
153<dl class="dl-horizontal">
154<dt>type</dt>
155<dd>the pre-defined type of kernel wanted </dd>
156
157<dd> </dd>
158<dt>args</dt>
159<dd>arguments defining or modifying the kernel </dd>
160
161<dd> Convolution Kernels </dd>
162
163<dd> Unity The a No-Op or Scaling single element kernel. </dd>
164
165<dd> Gaussian:{radius},{sigma} Generate a two-dimensional gaussian kernel, as used by -gaussian. The sigma for the curve is required.  The resulting kernel is normalized, </dd>
166
167<dd> If 'sigma' is zero, you get a single pixel on a field of zeros. </dd>
168
169<dd> NOTE: that the 'radius' is optional, but if provided can limit (clip) the final size of the resulting kernel to a square 2*radius+1 in size. The radius should be at least 2 times that of the sigma value, or sever clipping and aliasing may result.  If not given or set to 0 the radius will be determined so as to produce the best minimal error result, which is usally much larger than is normally needed. </dd>
170
171<dd> LoG:{radius},{sigma} "Laplacian of a Gaussian" or "Mexician Hat" Kernel. The supposed ideal edge detection, zero-summing kernel. </dd>
172
173<dd> An alturnative to this kernel is to use a "DoG" with a sigma ratio of approx 1.6 (according to wikipedia). </dd>
174
175<dd> DoG:{radius},{sigma1},{sigma2} "Difference of Gaussians" Kernel. As "Gaussian" but with a gaussian produced by 'sigma2' subtracted from the gaussian produced by 'sigma1'. Typically sigma2 &gt; sigma1. The result is a zero-summing kernel. </dd>
176
177<dd> Blur:{radius},{sigma}[,{angle}] Generates a 1 dimensional or linear gaussian blur, at the angle given (current restricted to orthogonal angles).  If a 'radius' is given the kernel is clipped to a width of 2*radius+1.  Kernel can be rotated by a 90 degree angle. </dd>
178
179<dd> If 'sigma' is zero, you get a single pixel on a field of zeros. </dd>
180
181<dd> Note that two convolutions with two "Blur" kernels perpendicular to each other, is equivalent to a far larger "Gaussian" kernel with the same sigma value, However it is much faster to apply. This is how the "-blur" operator actually works. </dd>
182
183<dd> Comet:{width},{sigma},{angle} Blur in one direction only, much like how a bright object leaves a comet like trail.  The Kernel is actually half a gaussian curve, Adding two such blurs in opposite directions produces a Blur Kernel. Angle can be rotated in multiples of 90 degrees. </dd>
184
185<dd> Note that the first argument is the width of the kernel and not the radius of the kernel. </dd>
186
187<dd> Binomial:[{radius}] Generate a discrete kernel using a 2 dimentional Pascel's Triangle of values. Used for special forma of image filters. </dd>
188
189<dd> # Still to be implemented... # # Filter2D # Filter1D #    Set kernel values using a resize filter, and given scale (sigma) #    Cylindrical or Linear.   Is this possible with an image? # </dd>
190
191<dd> Named Constant Convolution Kernels </dd>
192
193<dd> All these are unscaled, zero-summing kernels by default. As such for non-HDRI version of ImageMagick some form of normalization, user scaling, and biasing the results is recommended, to prevent the resulting image being 'clipped'. </dd>
194
195<dd> The 3x3 kernels (most of these) can be circularly rotated in multiples of 45 degrees to generate the 8 angled varients of each of the kernels. </dd>
196
197<dd> Laplacian:{type} Discrete Lapacian Kernels, (without normalization) Type 0 :  3x3 with center:8 surounded by -1  (8 neighbourhood) Type 1 :  3x3 with center:4 edge:-1 corner:0 (4 neighbourhood) Type 2 :  3x3 with center:4 edge:1 corner:-2 Type 3 :  3x3 with center:4 edge:-2 corner:1 Type 5 :  5x5 laplacian Type 7 :  7x7 laplacian Type 15 : 5x5 LoG (sigma approx 1.4) Type 19 : 9x9 LoG (sigma approx 1.4) </dd>
198
199<dd> Sobel:{angle} Sobel 'Edge' convolution kernel (3x3) | -1, 0, 1 | | -2, 0,-2 | | -1, 0, 1 | </dd>
200
201<dd> Roberts:{angle} Roberts convolution kernel (3x3) |  0, 0, 0 | | -1, 1, 0 | |  0, 0, 0 | </dd>
202
203<dd> Prewitt:{angle} Prewitt Edge convolution kernel (3x3) | -1, 0, 1 | | -1, 0, 1 | | -1, 0, 1 | </dd>
204
205<dd> Compass:{angle} Prewitt's "Compass" convolution kernel (3x3) | -1, 1, 1 | | -1,-2, 1 | | -1, 1, 1 | </dd>
206
207<dd> Kirsch:{angle} Kirsch's "Compass" convolution kernel (3x3) | -3,-3, 5 | | -3, 0, 5 | | -3,-3, 5 | </dd>
208
209<dd> FreiChen:{angle} Frei-Chen Edge Detector is based on a kernel that is similar to the Sobel Kernel, but is designed to be isotropic. That is it takes into account the distance of the diagonal in the kernel. </dd>
210
211<dd> |   1,     0,   -1     | | sqrt(2), 0, -sqrt(2) | |   1,     0,   -1     | </dd>
212
213<dd> FreiChen:{type},{angle} </dd>
214
215<dd> Frei-Chen Pre-weighted kernels... </dd>
216
217<dd> Type 0:  default un-nomalized version shown above. </dd>
218
219<dd> Type 1: Orthogonal Kernel (same as type 11 below) |   1,     0,   -1     | | sqrt(2), 0, -sqrt(2) | / 2*sqrt(2) |   1,     0,   -1     | </dd>
220
221<dd> Type 2: Diagonal form of Kernel... |   1,     sqrt(2),    0     | | sqrt(2),   0,     -sqrt(2) | / 2*sqrt(2) |   0,    -sqrt(2)    -1     | </dd>
222
223<dd> However this kernel is als at the heart of the FreiChen Edge Detection Process which uses a set of 9 specially weighted kernel.  These 9 kernels not be normalized, but directly applied to the image. The results is then added together, to produce the intensity of an edge in a specific direction.  The square root of the pixel value can then be taken as the cosine of the edge, and at least 2 such runs at 90 degrees from each other, both the direction and the strength of the edge can be determined. </dd>
224
225<dd> Type 10: All 9 of the following pre-weighted kernels... </dd>
226
227<dd> Type 11: |   1,     0,   -1     | | sqrt(2), 0, -sqrt(2) | / 2*sqrt(2) |   1,     0,   -1     | </dd>
228
229<dd> Type 12: | 1, sqrt(2), 1 | | 0,   0,     0 | / 2*sqrt(2) | 1, sqrt(2), 1 | </dd>
230
231<dd> Type 13: | sqrt(2), -1,    0     | |  -1,      0,    1     | / 2*sqrt(2) |   0,      1, -sqrt(2) | </dd>
232
233<dd> Type 14: |    0,     1, -sqrt(2) | |   -1,     0,     1    | / 2*sqrt(2) | sqrt(2), -1,     0    | </dd>
234
235<dd> Type 15: | 0, -1, 0 | | 1,  0, 1 | / 2 | 0, -1, 0 | </dd>
236
237<dd> Type 16: |  1, 0, -1 | |  0, 0,  0 | / 2 | -1, 0,  1 | </dd>
238
239<dd> Type 17: |  1, -2,  1 | | -2,  4, -2 | / 6 | -1, -2,  1 | </dd>
240
241<dd> Type 18: | -2, 1, -2 | |  1, 4,  1 | / 6 | -2, 1, -2 | </dd>
242
243<dd> Type 19: | 1, 1, 1 | | 1, 1, 1 | / 3 | 1, 1, 1 | </dd>
244
245<dd> The first 4 are for edge detection, the next 4 are for line detection and the last is to add a average component to the results. </dd>
246
247<dd> Using a special type of '-1' will return all 9 pre-weighted kernels as a multi-kernel list, so that you can use them directly (without normalization) with the special "-set option:morphology:compose Plus" setting to apply the full FreiChen Edge Detection Technique. </dd>
248
249<dd> If 'type' is large it will be taken to be an actual rotation angle for the default FreiChen (type 0) kernel.  As such  FreiChen:45  will look like a  Sobel:45  but with 'sqrt(2)' instead of '2' values. </dd>
250
251<dd> WARNING: The above was layed out as per http://www.math.tau.ac.il/~turkel/notes/edge_detectors.pdf But rotated 90 degrees so direction is from left rather than the top. I have yet to find any secondary confirmation of the above. The only other source found was actual source code at http://ltswww.epfl.ch/~courstiv/exos_labos/sol3.pdf Neigher paper defineds the kernels in a way that looks locical or correct when taken as a whole. </dd>
252
253<dd> Boolean Kernels </dd>
254
255<dd> Diamond:[{radius}[,{scale}]] Generate a diamond shaped kernel with given radius to the points. Kernel size will again be radius*2+1 square and defaults to radius 1, generating a 3x3 kernel that is slightly larger than a square. </dd>
256
257<dd> Square:[{radius}[,{scale}]] Generate a square shaped kernel of size radius*2+1, and defaulting to a 3x3 (radius 1). </dd>
258
259<dd> Octagon:[{radius}[,{scale}]] Generate octagonal shaped kernel of given radius and constant scale. Default radius is 3 producing a 7x7 kernel. A radius of 1 will result in "Diamond" kernel. </dd>
260
261<dd> Disk:[{radius}[,{scale}]] Generate a binary disk, thresholded at the radius given, the radius may be a float-point value. Final Kernel size is floor(radius)*2+1 square. A radius of 5.3 is the default. </dd>
262
263<dd> NOTE: That a low radii Disk kernels produce the same results as many of the previously defined kernels, but differ greatly at larger radii.  Here is a table of equivalences... "Disk:1"    =&gt; "Diamond", "Octagon:1", or "Cross:1" "Disk:1.5"  =&gt; "Square" "Disk:2"    =&gt; "Diamond:2" "Disk:2.5"  =&gt; "Octagon" "Disk:2.9"  =&gt; "Square:2" "Disk:3.5"  =&gt; "Octagon:3" "Disk:4.5"  =&gt; "Octagon:4" "Disk:5.4"  =&gt; "Octagon:5" "Disk:6.4"  =&gt; "Octagon:6" All other Disk shapes are unique to this kernel, but because a "Disk" is more circular when using a larger radius, using a larger radius is preferred over iterating the morphological operation. </dd>
264
265<dd> Rectangle:{geometry} Simply generate a rectangle of 1's with the size given. You can also specify the location of the 'control point', otherwise the closest pixel to the center of the rectangle is selected. </dd>
266
267<dd> Properly centered and odd sized rectangles work the best. </dd>
268
269<dd> Symbol Dilation Kernels </dd>
270
271<dd> These kernel is not a good general morphological kernel, but is used more for highlighting and marking any single pixels in an image using, a "Dilate" method as appropriate. </dd>
272
273<dd> For the same reasons iterating these kernels does not produce the same result as using a larger radius for the symbol. </dd>
274
275<dd> Plus:[{radius}[,{scale}]] Cross:[{radius}[,{scale}]] Generate a kernel in the shape of a 'plus' or a 'cross' with a each arm the length of the given radius (default 2). </dd>
276
277<dd> NOTE: "plus:1" is equivalent to a "Diamond" kernel. </dd>
278
279<dd> Ring:{radius1},{radius2}[,{scale}] A ring of the values given that falls between the two radii. Defaults to a ring of approximataly 3 radius in a 7x7 kernel. This is the 'edge' pixels of the default "Disk" kernel, More specifically, "Ring" -&gt; "Ring:2.5,3.5,1.0" </dd>
280
281<dd> Hit and Miss Kernels </dd>
282
283<dd> Peak:radius1,radius2 Find any peak larger than the pixels the fall between the two radii. The default ring of pixels is as per "Ring". Edges Find flat orthogonal edges of a binary shape Corners Find 90 degree corners of a binary shape Diagonals:type A special kernel to thin the 'outside' of diagonals LineEnds:type Find end points of lines (for pruning a skeletion) Two types of lines ends (default to both) can be searched for Type 0: All line ends Type 1: single kernel for 4-conneected line ends Type 2: single kernel for simple line ends LineJunctions Find three line junctions (within a skeletion) Type 0: all line junctions Type 1: Y Junction kernel Type 2: Diagonal T Junction kernel Type 3: Orthogonal T Junction kernel Type 4: Diagonal X Junction kernel Type 5: Orthogonal + Junction kernel Ridges:type Find single pixel ridges or thin lines Type 1: Fine single pixel thick lines and ridges Type 2: Find two pixel thick lines and ridges ConvexHull Octagonal Thickening Kernel, to generate convex hulls of 45 degrees Skeleton:type Traditional skeleton generating kernels. Type 1: Tradional Skeleton kernel (4 connected skeleton) Type 2: HIPR2 Skeleton kernel (8 connected skeleton) Type 3: Thinning skeleton based on a ressearch paper by Dan S. Bloomberg (Default Type) ThinSE:type A huge variety of Thinning Kernels designed to preserve conectivity. many other kernel sets use these kernels as source definitions. Type numbers are 41-49, 81-89, 481, and 482 which are based on the super and sub notations used in the source research paper. </dd>
284
285<dd> Distance Measuring Kernels </dd>
286
287<dd> Different types of distance measuring methods, which are used with the a 'Distance' morphology method for generating a gradient based on distance from an edge of a binary shape, though there is a technique for handling a anti-aliased shape. </dd>
288
289<dd> See the 'Distance' Morphological Method, for information of how it is applied. </dd>
290
291<dd> Chebyshev:[{radius}][x{scale}[!]] Chebyshev Distance (also known as Tchebychev or Chessboard distance) is a value of one to any neighbour, orthogonal or diagonal. One why of thinking of it is the number of squares a 'King' or 'Queen' in chess needs to traverse reach any other position on a chess board. It results in a 'square' like distance function, but one where diagonals are given a value that is closer than expected. </dd>
292
293<dd> Manhattan:[{radius}][x{scale}[!]] Manhattan Distance (also known as Rectilinear, City Block, or the Taxi Cab distance metric), it is the distance needed when you can only travel in horizontal or vertical directions only.  It is the distance a 'Rook' in chess would have to travel, and results in a diamond like distances, where diagonals are further than expected. </dd>
294
295<dd> Octagonal:[{radius}][x{scale}[!]] An interleving of Manhatten and Chebyshev metrics producing an increasing octagonally shaped distance.  Distances matches those of the "Octagon" shaped kernel of the same radius.  The minimum radius and default is 2, producing a 5x5 kernel. </dd>
296
297<dd> Euclidean:[{radius}][x{scale}[!]] Euclidean distance is the 'direct' or 'as the crow flys' distance. However by default the kernel size only has a radius of 1, which limits the distance to 'Knight' like moves, with only orthogonal and diagonal measurements being correct.  As such for the default kernel you will get octagonal like distance function. </dd>
298
299<dd> However using a larger radius such as "Euclidean:4" you will get a much smoother distance gradient from the edge of the shape. Especially if the image is pre-processed to include any anti-aliasing pixels. Of course a larger kernel is slower to use, and not always needed. </dd>
300
301<dd> The first three Distance Measuring Kernels will only generate distances of exact multiples of {scale} in binary images. As such you can use a scale of 1 without loosing any information.  However you also need some scaling when handling non-binary anti-aliased shapes. </dd>
302
303<dd> The "Euclidean" Distance Kernel however does generate a non-integer fractional results, and as such scaling is vital even for binary shapes. </dd>
304
305<dd>  </dd>
306</dl>
307<h2><a href="../../api/MagickCore/morphology_8c.html" id="CloneKernelInfo">CloneKernelInfo</a></h2>
308
309<p>CloneKernelInfo() creates a new clone of the given Kernel List so that its can be modified without effecting the original.  The cloned kernel should be destroyed using DestoryKernelInfo() when no longer needed.</p>
310
311<p>The format of the CloneKernelInfo method is:</p>
312
313<pre class="text">
314KernelInfo *CloneKernelInfo(const KernelInfo *kernel)
315</pre>
316
317<p>A description of each parameter follows:</p>
318
319<dd>
320</dd>
321
322<dd> </dd>
323<dl class="dl-horizontal">
324<dt>kernel</dt>
325<dd>the Morphology/Convolution kernel to be cloned </dd>
326
327<dd>  </dd>
328</dl>
329<h2><a href="../../api/MagickCore/morphology_8c.html" id="DestroyKernelInfo">DestroyKernelInfo</a></h2>
330
331<p>DestroyKernelInfo() frees the memory used by a Convolution/Morphology kernel.</p>
332
333<p>The format of the DestroyKernelInfo method is:</p>
334
335<pre class="text">
336KernelInfo *DestroyKernelInfo(KernelInfo *kernel)
337</pre>
338
339<p>A description of each parameter follows:</p>
340
341<dd>
342</dd>
343
344<dd> </dd>
345<dl class="dl-horizontal">
346<dt>kernel</dt>
347<dd>the Morphology/Convolution kernel to be destroyed </dd>
348
349<dd>  </dd>
350</dl>
351<h2><a href="../../api/MagickCore/morphology_8c.html" id="MorphologyApply">MorphologyApply</a></h2>
352
353<p>MorphologyApply() applies a morphological method, multiple times using a list of multiple kernels.  This is the method that should be called by other 'operators' that internally use morphology operations as part of their processing.</p>
354
355<p>It is basically equivalent to as MorphologyImage() (see below) but without any user controls.  This allows internel programs to use this method to perform a specific task without possible interference by any API user supplied settings.</p>
356
357<p>It is MorphologyImage() task to extract any such user controls, and pass them to this function for processing.</p>
358
359<p>More specifically all given kernels should already be scaled, normalised, and blended appropriatally before being parred to this routine. The appropriate bias, and compose (typically 'UndefinedComposeOp') given.</p>
360
361<p>The format of the MorphologyApply method is:</p>
362
363<pre class="text">
364Image *MorphologyApply(const Image *image,MorphologyMethod method,
365  const ssize_t iterations,const KernelInfo *kernel,
366  const CompositeMethod compose,const double bias,
367  ExceptionInfo *exception)
368</pre>
369
370<p>A description of each parameter follows:</p>
371
372<dd>
373</dd>
374
375<dd> </dd>
376<dl class="dl-horizontal">
377<dt>image</dt>
378<dd>the source image </dd>
379
380<dd> </dd>
381<dt>method</dt>
382<dd>the morphology method to be applied. </dd>
383
384<dd> </dd>
385<dt>iterations</dt>
386<dd>apply the operation this many times (or no change). A value of -1 means loop until no change found. How this is applied may depend on the morphology method. Typically this is a value of 1. </dd>
387
388<dd> </dd>
389<dt>channel</dt>
390<dd>the channel type. </dd>
391
392<dd> </dd>
393<dt>kernel</dt>
394<dd>An array of double representing the morphology kernel. </dd>
395
396<dd> </dd>
397<dt>compose</dt>
398<dd>How to handle or merge multi-kernel results. If 'UndefinedCompositeOp' use default for the Morphology method. If 'NoCompositeOp' force image to be re-iterated by each kernel. Otherwise merge the results using the compose method given. </dd>
399
400<dd> </dd>
401<dt>bias</dt>
402<dd>Convolution Output Bias. </dd>
403
404<dd> </dd>
405<dt>exception</dt>
406<dd>return any errors or warnings in this structure. </dd>
407
408<dd>  </dd>
409</dl>
410<h2><a href="../../api/MagickCore/morphology_8c.html" id="This_is almost identical to the MorphologyPrimative">This is almost identical to the MorphologyPrimative</a></h2>
411
412<p>This is almost identical to the MorphologyPrimative() function above, but applies the primitive directly to the actual image using two passes, once in each direction, with the results of the previous (and current) row being re-used.</p>
413
414<p>That is after each row is 'Sync'ed' into the image, the next row makes use of those values as part of the calculation of the next row.  It repeats, but going in the oppisite (bottom-up) direction.</p>
415
416<p>Because of this 're-use of results' this function can not make use of multi- threaded, parellel processing. </p>
417<h2><a href="../../api/MagickCore/morphology_8c.html" id="MorphologyImage">MorphologyImage</a></h2>
418
419<p>MorphologyImage() applies a user supplied kernel to the image according to the given mophology method.</p>
420
421<p>This function applies any and all user defined settings before calling the above internal function MorphologyApply().</p>
422
423<p>User defined settings include... * Output Bias for Convolution and correlation ("-define convolve:bias=??") * Kernel Scale/normalize settings            ("-define convolve:scale=??") This can also includes the addition of a scaled unity kernel. * Show Kernel being applied            ("-define morphology:showKernel=1")</p>
424
425<p>Other operators that do not want user supplied options interfering, especially "convolve:bias" and "morphology:showKernel" should use MorphologyApply() directly.</p>
426
427<p>The format of the MorphologyImage method is:</p>
428
429<pre class="text">
430Image *MorphologyImage(const Image *image,MorphologyMethod method,
431  const ssize_t iterations,KernelInfo *kernel,ExceptionInfo *exception)
432</pre>
433
434<p>A description of each parameter follows:</p>
435
436<dd>
437</dd>
438
439<dd> </dd>
440<dl class="dl-horizontal">
441<dt>image</dt>
442<dd>the image. </dd>
443
444<dd> </dd>
445<dt>method</dt>
446<dd>the morphology method to be applied. </dd>
447
448<dd> </dd>
449<dt>iterations</dt>
450<dd>apply the operation this many times (or no change). A value of -1 means loop until no change found. How this is applied may depend on the morphology method. Typically this is a value of 1. </dd>
451
452<dd> </dd>
453<dt>kernel</dt>
454<dd>An array of double representing the morphology kernel. Warning: kernel may be normalized for the Convolve method. </dd>
455
456<dd> </dd>
457<dt>exception</dt>
458<dd>return any errors or warnings in this structure. </dd>
459
460<dd>  </dd>
461</dl>
462<h2><a href="../../api/MagickCore/morphology_8c.html" id="ScaleGeometryKernelInfo">ScaleGeometryKernelInfo</a></h2>
463
464<p>ScaleGeometryKernelInfo() takes a geometry argument string, typically provided as a  "-set option:convolve:scale {geometry}" user setting, and modifies the kernel according to the parsed arguments of that setting.</p>
465
466<p>The first argument (and any normalization flags) are passed to ScaleKernelInfo() to scale/normalize the kernel.  The second argument is then passed to UnityAddKernelInfo() to add a scled unity kernel into the scaled/normalized kernel.</p>
467
468<p>The format of the ScaleGeometryKernelInfo method is:</p>
469
470<pre class="text">
471void ScaleGeometryKernelInfo(KernelInfo *kernel,
472  const double scaling_factor,const MagickStatusType normalize_flags)
473</pre>
474
475<p>A description of each parameter follows:</p>
476
477<dd>
478</dd>
479
480<dd> </dd>
481<dl class="dl-horizontal">
482<dt>kernel</dt>
483<dd>the Morphology/Convolution kernel to modify </dd>
484
485<dd> o geometry: </dd>
486
487<pre class="text">
488       "-set option:convolve:scale {geometry}" setting.
489</pre>
490
491<p></dd>
492</dl>
493<h2><a href="../../api/MagickCore/morphology_8c.html" id="ScaleKernelInfo">ScaleKernelInfo</a></h2>
494
495<p>ScaleKernelInfo() scales the given kernel list by the given amount, with or without normalization of the sum of the kernel values (as per given flags).</p>
496
497<p>By default (no flags given) the values within the kernel is scaled directly using given scaling factor without change.</p>
498
499<p>If either of the two 'normalize_flags' are given the kernel will first be normalized and then further scaled by the scaling factor value given.</p>
500
501<p>Kernel normalization ('normalize_flags' given) is designed to ensure that any use of the kernel scaling factor with 'Convolve' or 'Correlate' morphology methods will fall into -1.0 to +1.0 range.  Note that for non-HDRI versions of IM this may cause images to have any negative results clipped, unless some 'bias' is used.</p>
502
503<p>More specifically.  Kernels which only contain positive values (such as a 'Gaussian' kernel) will be scaled so that those values sum to +1.0, ensuring a 0.0 to +1.0 output range for non-HDRI images.</p>
504
505<p>For Kernels that contain some negative values, (such as 'Sharpen' kernels) the kernel will be scaled by the absolute of the sum of kernel values, so that it will generally fall within the +/- 1.0 range.</p>
506
507<p>For kernels whose values sum to zero, (such as 'Laplician' kernels) kernel will be scaled by just the sum of the postive values, so that its output range will again fall into the  +/- 1.0 range.</p>
508
509<p>For special kernels designed for locating shapes using 'Correlate', (often only containing +1 and -1 values, representing foreground/brackground matching) a special normalization method is provided to scale the positive values separately to those of the negative values, so the kernel will be forced to become a zero-sum kernel better suited to such searches.</p>
510
511<p>WARNING: Correct normalization of the kernel assumes that the '*_range' attributes within the kernel structure have been correctly set during the kernels creation.</p>
512
513<p>NOTE: The values used for 'normalize_flags' have been selected specifically to match the use of geometry options, so that '!' means NormalizeValue, '^' means CorrelateNormalizeValue.  All other GeometryFlags values are ignored.</p>
514
515<p>The format of the ScaleKernelInfo method is:</p>
516
517<pre class="text">
518void ScaleKernelInfo(KernelInfo *kernel, const double scaling_factor,
519         const MagickStatusType normalize_flags )
520</pre>
521
522<p>A description of each parameter follows:</p>
523
524<dd>
525</dd>
526
527<dd> </dd>
528<dl class="dl-horizontal">
529<dt>kernel</dt>
530<dd>the Morphology/Convolution kernel </dd>
531
532<dd> o scaling_factor: </dd>
533
534<pre class="text">
535       zero.  If the kernel is normalized regardless of any flags.
536</pre>
537
538<p>o normalize_flags: </dd>
539
540<pre class="text">
541       specifically: NormalizeValue, CorrelateNormalizeValue,
542                     and/or PercentValue
543</pre>
544
545<p></dd>
546</dl>
547<h2><a href="../../api/MagickCore/morphology_8c.html" id="ShowKernelInfo">ShowKernelInfo</a></h2>
548
549<p>ShowKernelInfo() outputs the details of the given kernel defination to standard error, generally due to a users 'morphology:showKernel' option request.</p>
550
551<p>The format of the ShowKernel method is:</p>
552
553<pre class="text">
554void ShowKernelInfo(const KernelInfo *kernel)
555</pre>
556
557<p>A description of each parameter follows:</p>
558
559<dd>
560</dd>
561
562<dd> </dd>
563<dl class="dl-horizontal">
564<dt>kernel</dt>
565<dd>the Morphology/Convolution kernel </dd>
566
567<dd>  </dd>
568</dl>
569<h2><a href="../../api/MagickCore/morphology_8c.html" id="UnityAddKernelInfo">UnityAddKernelInfo</a></h2>
570
571<p>UnityAddKernelInfo() Adds a given amount of the 'Unity' Convolution Kernel to the given pre-scaled and normalized Kernel.  This in effect adds that amount of the original image into the resulting convolution kernel.  This value is usually provided by the user as a percentage value in the 'convolve:scale' setting.</p>
572
573<p>The resulting effect is to convert the defined kernels into blended soft-blurs, unsharp kernels or into sharpening kernels.</p>
574
575<p>The format of the UnityAdditionKernelInfo method is:</p>
576
577<pre class="text">
578void UnityAdditionKernelInfo(KernelInfo *kernel, const double scale )
579</pre>
580
581<p>A description of each parameter follows:</p>
582
583<dd>
584</dd>
585
586<dd> </dd>
587<dl class="dl-horizontal">
588<dt>kernel</dt>
589<dd>the Morphology/Convolution kernel </dd>
590
591<dd> o scale: </dd>
592
593<pre class="text">
594       the given kernel.
595</pre>
596
597<p></dd>
598</dl>
599<h2><a href="../../api/MagickCore/morphology_8c.html" id="ZeroKernelNans">ZeroKernelNans</a></h2>
600
601<p>ZeroKernelNans() replaces any special 'nan' value that may be present in the kernel with a zero value.  This is typically done when the kernel will be used in special hardware (GPU) convolution processors, to simply matters.</p>
602
603<p>The format of the ZeroKernelNans method is:</p>
604
605<pre class="text">
606void ZeroKernelNans (KernelInfo *kernel)
607</pre>
608
609<p>A description of each parameter follows:</p>
610
611<dd>
612</dd>
613
614<dd> </dd>
615<dl class="dl-horizontal">
616<dt>kernel</dt>
617<dd>the Morphology/Convolution kernel </dd>
618
619<dd>  </dd>
620</dl>
621</div>
622    </div>
623  </main><!-- /.container -->
624  <footer class="magick-footer">
625    <p><a href="../../www/security-policy.html">Security</a> •
626    <a href="../../www/architecture.html">Architecture</a> •
627    <a href="../../www/links.html">Related</a> •
628     <a href="../../www/sitemap.html">Sitemap</a>
629
630    <a href="morphology.html#"><img class="d-inline" id="wand" alt="And Now a Touch of Magick" width="16" height="16" src="../../images/wand.ico"/></a>
631
632    <a href="http://pgp.mit.edu/pks/lookup?op=get&amp;search=0x89AB63D48277377A">Public Key</a> •
633    <a href="../../www/support.html">Donate</a> •
634    <a href="../../www/contact.html">Contact Us</a>
635    <br/>
636    <small>© 1999-2019 ImageMagick Studio LLC</small></p>
637  </footer>
638
639  <!-- Javascript assets -->
640  <script src="../assets/magick.js" crossorigin="anonymous"></script>
641  <script>window.jQuery || document.write('<script src="https://localhost/ajax/libs/jquery/3.3.1/jquery.min.js"><\/script>')</script>
642</body>
643</html>
644<!-- Magick Cache 2nd January 2019 23:14 -->