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, initial-scale=1" /> 10 <title>ImageMagick - MagickCore, Low-level C API</title> 11 <meta name="application-name" content="ImageMagick" /> 12 <meta name="description" content="Use ImageMagick® to create, edit, compose, and convert digital images. 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Unlike the <a href="api/MagickWand/index.html">MagickWand</a> C API which uses only a few opaque types and accessors, with MagickCore you almost exlusively access the structure members directly. A description of the MagickCore public methods are found here:</p> 96 97<ul> 98 <li><a href="api/magick.html">Initialize or Destroy the ImageMagick Environment</a></li> 99 <li><a href="api/constitute.html">Constitute an Image</a></li> 100 <li><a href="api/composite.html">Composite an Image</a></li> 101 <li><a href="api/image.html">Image Methods</a></li> 102 <li><a href="api/channel.html">Image Channel Methods</a></li> 103 <li><a href="api/color.html">Count the Colors in an Image</a></li> 104 <li><a href="api/colormap.html">Colormap Methods</a></li> 105 <li><a href="api/colorspace.html">Colorspace Methods</a></li> 106 <li><a href="api/distort.html">Image Distortions</a></li> 107 <li><a href="api/layer.html">Dealing with Image Layers</a></li> 108 <li><a href="api/profile.html">Dealing with Image Profiles</a></li> 109 <li><a href="api/quantize.html">Reduce the Number of Unique Colors in an Image</a></li> 110 <li><a href="api/histogram.html">Image Histograms</a></li> 111 <li><a href="api/segment.html">Segment an Image with Thresholding Fuzzy c-Means</a></li> 112 <li><a href="api/resize.html">Resize an Image</a></li> 113 <li><a href="api/transform.html">Transform an Image</a></li> 114 <li><a href="api/shear.html">Shear or Rotate an Image by an Arbitrary Angle</a></li> 115 <li><a href="api/enhance.html">Enhance an Image</a></li> 116 <li><a href="api/effect.html">Add an Effect</a></li> 117 <li><a href="api/morphology.html">Morphological Erosions, Dilations, Openings, and Closings</a></li> 118 <li><a href="api/fx.html">Add a Special Effect</a></li> 119 <li><a href="api/decorate.html">Decorate an Image</a></li> 120 <li><a href="api/attribute.html">Get/Set an Image Attribute</a></li> 121 <li><a href="api/property.html">Get/Set Image Properties</a></li> 122 <li><a href="api/statistic.html">Get Image Statistics</a></li> 123 <li><a href="api/feature.html">Get Image Features</a></li> 124 <li><a href="api/annotate.html">Annotate an Image</a></li> 125 <li><a href="api/paint.html">Paint on an Image</a></li> 126 <li><a href="api/draw.html">Draw on an Image</a></li> 127 <li><a href="api/montage.html">Create an Image Thumbnail</a></li> 128 <li><a href="api/fourier.html">Compute the discrete Fourier transform (DFT)</a></li> 129 <li><a href="api/compare.html">Compare an Image to a Reconstructed Image</a></li> 130 <li><a href="api/display.html">Interactively Display and Edit an Image</a></li> 131 <li><a href="api/animate.html">Interactively Animate an Image Sequence</a></li> 132 <li><a href="api/cipher.html">Convert to and from Cipher Pixels</a></li> 133 <li><a href="api/list.html">Working with Image Lists</a></li> 134 <li><a href="api/image-view.html">Image View Methods</a></li> 135 <li><a href="api/cache.html">Get or Set Image Pixels</a></li> 136 <li><a href="api/cache-view.html">Working with Cache Views</a></li> 137 <li><a href="api/stream.html">The Pixel FIFO</a></li> 138 <li><a href="api/blob.html">Read or Write Binary Large OBjects</a></li> 139 <li><a href="api/module.html">Loadable Modules</a></li> 140 <li><a href="api/signature.html">Compute a Message Digest for an Image</a></li> 141 <li><a href="api/registry.html">The Image Registry</a></li> 142 <li><a href="api/exception.html">Dealing with Exceptions</a></li> 143 <li><a href="api/memory.html">Memory Allocation</a></li> 144 <li><a href="api/resource.html">Monitor or Limit Resource Consumption</a></li> 145 <li><a href="api/monitor.html">Monitor the Progress of an Image Operation</a></li> 146 <li><a href="api/version.html">Get the Version and Copyrights</a></li> 147 <li><a href="api/mime.html">Mime Methods</a></li> 148 <li><a href="api/deprecate.html">Deprecated Methods</a></li> 149 <li><a href="exception.html">Error and Warning Codes</a></li> 150</ul> 151 152<p>After you write your MagickCore program, compile it like this:</p> 153 154<ul><pre class="highlight"><code>cc -o core core.c `pkg-config --cflags --libs MagickWand`</code></pre></ul> 155 156<p>Set the <code>PKG_CONFIG_PATH</code> environment variable if ImageMagick is not in your default system path:</p> 157 158<ul><pre class="highlight"><code>export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig </code></pre></ul> 159 160<p>Here is a example program that utilizes the MagickCore API to get you started, <a href="https://imagemagick.org/source/core.c">core.c</a>. It reads a GIF image, creates a thumbnail, and writes it to disk in the PNG image format.</p> 161 162<ul><pre class="pre-scrollable highlight"><code>#include <stdio.h> 163#include <stdlib.h> 164#include <string.h> 165#include <time.h> 166#include <MagickCore/MagickCore.h> 167 168int main(int argc,char **argv) 169{ 170 ExceptionInfo 171 *exception; 172 173 Image 174 *image, 175 *images, 176 *resize_image, 177 *thumbnails; 178 179 ImageInfo 180 *image_info; 181 182 if (argc != 3) 183 { 184 (void) fprintf(stdout,"Usage: %s image thumbnail\n",argv[0]); 185 exit(0); 186 } 187 /* 188 Initialize the image info structure and read an image. 189 */ 190 MagickCoreGenesis(*argv,MagickTrue); 191 exception=AcquireExceptionInfo(); 192 image_info=CloneImageInfo((ImageInfo *) NULL); 193 (void) strcpy(image_info->filename,argv[1]); 194 images=ReadImage(image_info,exception); 195 if (exception->severity != UndefinedException) 196 CatchException(exception); 197 if (images == (Image *) NULL) 198 exit(1); 199 /* 200 Convert the image to a thumbnail. 201 */ 202 thumbnails=NewImageList(); 203 while ((image=RemoveFirstImageFromList(&images)) != (Image *) NULL) 204 { 205 resize_image=ResizeImage(image,106,80,LanczosFilter,exception); 206 if (resize_image == (Image *) NULL) 207 MagickError(exception->severity,exception->reason,exception->description); 208 (void) AppendImageToList(&thumbnails,resize_image); 209 DestroyImage(image); 210 } 211 /* 212 Write the image thumbnail. 213 */ 214 (void) strcpy(thumbnails->filename,argv[2]); 215 WriteImage(image_info,thumbnails,exception); 216 /* 217 Destroy the image thumbnail and exit. 218 */ 219 thumbnails=DestroyImageList(thumbnails); 220 image_info=DestroyImageInfo(image_info); 221 exception=DestroyExceptionInfo(exception); 222 MagickCoreTerminus(); 223 return(0); 224}</code></pre></ul> 225<p><a class="anchor" id="image-view"></a>Now lets perform the same contrast enhancement while taking advantage of our dual or quad-core processing system by running the algorithm in parallel utilizing wand views. The <a href="https://imagemagick.org/source/core/sigmoidal-contrast.c">sigmoidal-contrast.c</a> module reads an image, applies sigmoidal non-linearity contrast control, and writes the result to disk just like the previous contrast enhancement program, but now it does its work in parallel (assumes ImageMagick is built with OpenMP support).</p> 226 227<ul><pre class="pre-scrollable highlight"><code>#include <stdio.h> 228#include <stdlib.h> 229#include <math.h> 230#include <MagickCore/MagickCore.h> 231 232static MagickBooleanType SigmoidalContrast(ImageView *contrast_view, 233 const ssize_t y,const int id,void *context) 234{ 235#define QuantumScale ((MagickRealType) 1.0/(MagickRealType) QuantumRange) 236#define SigmoidalContrast(x) \ 237 (QuantumRange*(1.0/(1+exp(10.0*(0.5-QuantumScale*x)))-0.0066928509)*1.0092503) 238 239 RectangleInfo 240 extent; 241 242 register IndexPacket 243 *indexes; 244 245 register PixelPacket 246 *pixels; 247 248 register ssize_t 249 x; 250 251 extent=GetImageViewExtent(contrast_view); 252 pixels=GetImageViewAuthenticPixels(contrast_view); 253 for (x=0; x < (ssize_t) (extent.width-extent.x); x++) 254 { 255 SetPixelRed(pixels,RoundToQuantum(SigmoidalContrast(GetPixelRed(pixels))); 256 SetPixelGreen(pixels,RoundToQuantum(SigmoidalContrast(GetPixelGreen(pixels))); 257 SetPixelBlue(pixels,RoundToQuantum(SigmoidalContrast(GetPixelBlue(pixels))); 258 SetPixelOpacity(pixels,RoundToQuantum(SigmoidalContrast(GetPixelOpacity(pixels))); 259 pixels++; 260 } 261 indexes=GetImageViewAuthenticIndexes(contrast_view); 262 if (indexes != (IndexPacket *) NULL) 263 for (x=0; x < (ssize_t) (extent.width-extent.x); x++) 264 SetPixelIndex(indexes+x,RoundToQuantum(SigmoidalContrast(GetPixelIndex(indexes+x)))); 265 return(MagickTrue); 266} 267 268int main(int argc,char **argv) 269{ 270#define ThrowImageException(image) \ 271{ \ 272 \ 273 CatchException(exception); \ 274 if (contrast_image != (Image *) NULL) \ 275 contrast_image=DestroyImage(contrast_image); \ 276 exit(-1); \ 277} 278#define ThrowViewException(view) \ 279{ \ 280 char \ 281 *description; \ 282 \ 283 ExceptionType \ 284 severity; \ 285 \ 286 description=GetImageViewException(view,&severity); \ 287 (void) fprintf(stderr,"%s %s %lu %s\n",GetMagickModule(),description); \ 288 description=DestroyString(description); \ 289 exit(-1); \ 290} 291 292 ExceptionInfo 293 *exception; 294 295 Image 296 *contrast_image; 297 298 ImageInfo 299 *image_info; 300 301 ImageView 302 *contrast_view; 303 304 MagickBooleanType 305 status; 306 307 if (argc != 3) 308 { 309 (void) fprintf(stdout,"Usage: %s image sigmoidal-image\n",argv[0]); 310 exit(0); 311 } 312 /* 313 Read an image. 314 */ 315 MagickCoreGenesis(*argv,MagickTrue); 316 image_info=AcquireImageInfo(); 317 (void) CopyMagickString(image_info->filename,argv[1],MaxTextExtent); 318 exception=AcquireExceptionInfo(); 319 contrast_image=ReadImage(image_info,exception); 320 if (contrast_image == (Image *) NULL) 321 ThrowImageException(contrast_image); 322 /* 323 Sigmoidal non-linearity contrast control. 324 */ 325 contrast_view=NewImageView(contrast_image); 326 if (contrast_view == (ImageView *) NULL) 327 ThrowImageException(contrast_image); 328 status=UpdateImageViewIterator(contrast_view,SigmoidalContrast,(void *) NULL); 329 if (status == MagickFalse) 330 ThrowImageException(contrast_image); 331 contrast_view=DestroyImageView(contrast_view); 332 /* 333 Write the image then destroy it. 334 */ 335 status=WriteImages(image_info,contrast_image,argv[2],exception); 336 if (status == MagickFalse) 337 ThrowImageException(contrast_image); 338 contrast_image=DestroyImage(contrast_image); 339 exception=DestroyExceptionInfo(exception); 340 image_info=DestroyImageInfo(image_info); 341 MagickCoreTerminus(); 342 return(0); 343}</code></pre></ul> 344</div> 345 </div> 346 </main><!-- /.container --> 347 <footer class="magick-footer"> 348 <div class="container-fluid"> 349 <a href="../www/security-policy.html">Security</a> • 350 <a href="../www/news.html">News</a> 351 352 <a href="magick-core.html#"><img class="d-inline" id="wand" alt="And Now a Touch of Magick" width="16" height="16" src="../images/wand.ico"/></a> 353 354 <a href="../www/links.html">Related</a> • 355 <a href="../www/sitemap.html">Sitemap</a> 356 <br/> 357 <a href="../www/support.html">Sponsor</a> • 358 <a href="../www/cite.html">Cite</a> • 359 <a href="http://pgp.mit.edu/pks/lookup?op=get&search=0x89AB63D48277377A">Public Key</a> • 360 <a href="../www/https://imagemagick.org/script/contact.php">Contact Us</a> 361 <br/> 362 <a href="https://github.com/imagemagick/imagemagick" target="_blank" rel="noopener" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" class="navbar-nav-svg" viewBox="0 0 512 499.36" width="2%" height="2%" role="img" focusable="false"><title>GitHub</title><path fill="currentColor" fill-rule="evenodd" d="M256 0C114.64 0 0 114.61 0 256c0 113.09 73.34 209 175.08 242.9 12.8 2.35 17.47-5.56 17.47-12.34 0-6.08-.22-22.18-.35-43.54-71.2 15.49-86.2-34.34-86.2-34.34-11.64-29.57-28.42-37.45-28.42-37.45-23.27-15.84 1.73-15.55 1.73-15.55 25.69 1.81 39.21 26.38 39.21 26.38 22.84 39.12 59.92 27.82 74.5 21.27 2.33-16.54 8.94-27.82 16.25-34.22-56.84-6.43-116.6-28.43-116.6-126.49 0-27.95 10-50.8 26.35-68.69-2.63-6.48-11.42-32.5 2.51-67.75 0 0 21.49-6.88 70.4 26.24a242.65 242.65 0 0 1 128.18 0c48.87-33.13 70.33-26.24 70.33-26.24 14 35.25 5.18 61.27 2.55 67.75 16.41 17.9 26.31 40.75 26.31 68.69 0 98.35-59.85 120-116.88 126.32 9.19 7.9 17.38 23.53 17.38 47.41 0 34.22-.31 61.83-.31 70.23 0 6.85 4.61 14.81 17.6 12.31C438.72 464.97 512 369.08 512 256.02 512 114.62 397.37 0 256 0z"/></svg></a> • 363 <a href="https://twitter.com/imagemagick" target="_blank" rel="noopener" aria-label="Twitter"><svg xmlns="http://www.w3.org/2000/svg" class="navbar-nav-svg" viewBox="0 0 512 416.32" width="2%" height="2%" role="img" focusable="false"><title>Twitter</title><path fill="currentColor" d="M160.83 416.32c193.2 0 298.92-160.22 298.92-298.92 0-4.51 0-9-.2-13.52A214 214 0 0 0 512 49.38a212.93 212.93 0 0 1-60.44 16.6 105.7 105.7 0 0 0 46.3-58.19 209 209 0 0 1-66.79 25.37 105.09 105.09 0 0 0-181.73 71.91 116.12 116.12 0 0 0 2.66 24c-87.28-4.3-164.73-46.3-216.56-109.82A105.48 105.48 0 0 0 68 159.6a106.27 106.27 0 0 1-47.53-13.11v1.43a105.28 105.28 0 0 0 84.21 103.06 105.67 105.67 0 0 1-47.33 1.84 105.06 105.06 0 0 0 98.14 72.94A210.72 210.72 0 0 1 25 370.84a202.17 202.17 0 0 1-25-1.43 298.85 298.85 0 0 0 160.83 46.92"/></svg></a> 364 <br/> 365 <small>© 1999-2021 ImageMagick Studio LLC</small> 366 </div> 367 </footer> 368 369 <!-- Javascript assets --> 370 <script src="assets/magick.js" ></script> 371 </body> 372</html> 373<!-- Magick Cache 13th February 2021 14:08 -->
