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, Low-level C API @ ImageMagick</title> 11 <meta name="application-name" content="ImageMagick" /> 12 <meta name="description" content="Use ImageMagick® to create, edit, compose, or convert bitmap images. 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Unlike the <a href="magick-wand.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> 86 87<ul> 88 <li><a href="api/magick.html">Initialize or Destroy the ImageMagick Environment</a></li> 89 <li><a href="api/constitute.html">Constitute an Image</a></li> 90 <li><a href="api/composite.html">Composite an Image</a></li> 91 <li><a href="api/image.html">Image Methods</a></li> 92 <li><a href="api/channel.html">Image Channel Methods</a></li> 93 <li><a href="api/color.html">Count the Colors in an Image</a></li> 94 <li><a href="api/colormap.html">Colormap Methods</a></li> 95 <li><a href="api/colorspace.html">Colorspace Methods</a></li> 96 <li><a href="api/distort.html">Image Distortions</a></li> 97 <li><a href="api/layer.html">Dealing with Image Layers</a></li> 98 <li><a href="api/profile.html">Dealing with Image Profiles</a></li> 99 <li><a href="api/quantize.html">Reduce the Number of Unique Colors in an Image</a></li> 100 <li><a href="api/histogram.html">Image Histograms</a></li> 101 <li><a href="api/segment.html">Segment an Image with Thresholding Fuzzy c-Means</a></li> 102 <li><a href="api/resize.html">Resize an Image</a></li> 103 <li><a href="api/transform.html">Transform an Image</a></li> 104 <li><a href="api/shear.html">Shear or Rotate an Image by an Arbitrary Angle</a></li> 105 <li><a href="api/enhance.html">Enhance an Image</a></li> 106 <li><a href="api/effect.html">Add an Effect</a></li> 107 <li><a href="api/morphology.html">Morphological Erosions, Dilations, Openings, and Closings</a></li> 108 <li><a href="api/fx.html">Add a Special Effect</a></li> 109 <li><a href="api/decorate.html">Decorate an Image</a></li> 110 <li><a href="api/attribute.html">Get/Set an Image Attribute</a></li> 111 <li><a href="api/property.html">Get/Set Image Properties</a></li> 112 <li><a href="api/statistic.html">Get Image Statistics</a></li> 113 <li><a href="api/feature.html">Get Image Features</a></li> 114 <li><a href="api/annotate.html">Annotate an Image</a></li> 115 <li><a href="api/paint.html">Paint on an Image</a></li> 116 <li><a href="api/draw.html">Draw on an Image</a></li> 117 <li><a href="api/montage.html">Create an Image Thumbnail</a></li> 118 <li><a href="api/fourier.html">Compute the discrete Fourier transform (DFT)</a></li> 119 <li><a href="api/compare.html">Compare an Image to a Reconstructed Image</a></li> 120 <li><a href="api/display.html">Interactively Display and Edit an Image</a></li> 121 <li><a href="api/animate.html">Interactively Animate an Image Sequence</a></li> 122 <li><a href="api/cipher.html">Convert to and from Cipher Pixels</a></li> 123 <li><a href="api/list.html">Working with Image Lists</a></li> 124 <li><a href="api/image-view.html">Image View Methods</a></li> 125 <li><a href="api/cache.html">Get or Set Image Pixels</a></li> 126 <li><a href="api/cache-view.html">Working with Cache Views</a></li> 127 <li><a href="api/stream.html">The Pixel FIFO</a></li> 128 <li><a href="api/blob.html">Read or Write Binary Large OBjects</a></li> 129 <li><a href="api/module.html">Loadable Modules</a></li> 130 <li><a href="api/signature.html">Compute a Message Digest for an Image</a></li> 131 <li><a href="api/registry.html">The Image Registry</a></li> 132 <li><a href="api/exception.html">Dealing with Exceptions</a></li> 133 <li><a href="api/memory.html">Memory Allocation</a></li> 134 <li><a href="api/resource.html">Monitor or Limit Resource Consumption</a></li> 135 <li><a href="api/monitor.html">Monitor the Progress of an Image Operation</a></li> 136 <li><a href="api/version.html">Get the Version and Copyrights</a></li> 137 <li><a href="api/mime.html">Mime Methods</a></li> 138 <li><a href="api/deprecate.html">Deprecated Methods</a></li> 139 <li><a href="exception.html">Error and Warning Codes</a></li> 140</ul> 141 142<p>After you write your MagickCore program, compile it like this:</p> 143 144<pre class="highlight"><code>cc -o core core.c `pkg-config --cflags --libs MagickWand` 145</code></pre> 146 147<p>Set the <code>PKG_CONFIG_PATH</code> environment variable if ImageMagick is not in your default system path:</p> 148 149<pre class="highlight"><code>export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig 150</code></pre> 151 152<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> 153 154<pre class="pre-scrollable"><code>#include <stdio.h> 155#include <stdlib.h> 156#include <string.h> 157#include <time.h> 158#include <MagickCore/MagickCore.h> 159 160int main(int argc,char **argv) 161{ 162 ExceptionInfo 163 *exception; 164 165 Image 166 *image, 167 *images, 168 *resize_image, 169 *thumbnails; 170 171 ImageInfo 172 *image_info; 173 174 if (argc != 3) 175 { 176 (void) fprintf(stdout,"Usage: %s image thumbnail\n",argv[0]); 177 exit(0); 178 } 179 /* 180 Initialize the image info structure and read an image. 181 */ 182 MagickCoreGenesis(*argv,MagickTrue); 183 exception=AcquireExceptionInfo(); 184 image_info=CloneImageInfo((ImageInfo *) NULL); 185 (void) strcpy(image_info->filename,argv[1]); 186 images=ReadImage(image_info,exception); 187 if (exception->severity != UndefinedException) 188 CatchException(exception); 189 if (images == (Image *) NULL) 190 exit(1); 191 /* 192 Convert the image to a thumbnail. 193 */ 194 thumbnails=NewImageList(); 195 while ((image=RemoveFirstImageFromList(&images)) != (Image *) NULL) 196 { 197 resize_image=ResizeImage(image,106,80,LanczosFilter,exception); 198 if (resize_image == (Image *) NULL) 199 MagickError(exception->severity,exception->reason,exception->description); 200 (void) AppendImageToList(&thumbnails,resize_image); 201 DestroyImage(image); 202 } 203 /* 204 Write the image thumbnail. 205 */ 206 (void) strcpy(thumbnails->filename,argv[2]); 207 WriteImage(image_info,thumbnails,exception); 208 /* 209 Destroy the image thumbnail and exit. 210 */ 211 thumbnails=DestroyImageList(thumbnails); 212 image_info=DestroyImageInfo(image_info); 213 exception=DestroyExceptionInfo(exception); 214 MagickCoreTerminus(); 215 return(0); 216}</code></pre> 217<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> 218 219<pre class="pre-scrollable"><code>#include <stdio.h> 220#include <stdlib.h> 221#include <math.h> 222#include <MagickCore/MagickCore.h> 223 224static MagickBooleanType SigmoidalContrast(ImageView *contrast_view, 225 const ssize_t y,const int id,void *context) 226{ 227#define QuantumScale ((MagickRealType) 1.0/(MagickRealType) QuantumRange) 228#define SigmoidalContrast(x) \ 229 (QuantumRange*(1.0/(1+exp(10.0*(0.5-QuantumScale*x)))-0.0066928509)*1.0092503) 230 231 RectangleInfo 232 extent; 233 234 register IndexPacket 235 *indexes; 236 237 register PixelPacket 238 *pixels; 239 240 register ssize_t 241 x; 242 243 extent=GetImageViewExtent(contrast_view); 244 pixels=GetImageViewAuthenticPixels(contrast_view); 245 for (x=0; x < (ssize_t) (extent.width-extent.x); x++) 246 { 247 SetPixelRed(pixels,RoundToQuantum(SigmoidalContrast(GetPixelRed(pixels))); 248 SetPixelGreen(pixels,RoundToQuantum(SigmoidalContrast(GetPixelGreen(pixels))); 249 SetPixelBlue(pixels,RoundToQuantum(SigmoidalContrast(GetPixelBlue(pixels))); 250 SetPixelOpacity(pixels,RoundToQuantum(SigmoidalContrast(GetPixelOpacity(pixels))); 251 pixels++; 252 } 253 indexes=GetImageViewAuthenticIndexes(contrast_view); 254 if (indexes != (IndexPacket *) NULL) 255 for (x=0; x < (ssize_t) (extent.width-extent.x); x++) 256 SetPixelIndex(indexes+x,RoundToQuantum(SigmoidalContrast(GetPixelIndex(indexes+x)))); 257 return(MagickTrue); 258} 259 260int main(int argc,char **argv) 261{ 262#define ThrowImageException(image) \ 263{ \ 264 \ 265 CatchException(exception); \ 266 if (contrast_image != (Image *) NULL) \ 267 contrast_image=DestroyImage(contrast_image); \ 268 exit(-1); \ 269} 270#define ThrowViewException(view) \ 271{ \ 272 char \ 273 *description; \ 274 \ 275 ExceptionType \ 276 severity; \ 277 \ 278 description=GetImageViewException(view,&severity); \ 279 (void) fprintf(stderr,"%s %s %lu %s\n",GetMagickModule(),description); \ 280 description=DestroyString(description); \ 281 exit(-1); \ 282} 283 284 ExceptionInfo 285 *exception; 286 287 Image 288 *contrast_image; 289 290 ImageInfo 291 *image_info; 292 293 ImageView 294 *contrast_view; 295 296 MagickBooleanType 297 status; 298 299 if (argc != 3) 300 { 301 (void) fprintf(stdout,"Usage: %s image sigmoidal-image\n",argv[0]); 302 exit(0); 303 } 304 /* 305 Read an image. 306 */ 307 MagickCoreGenesis(*argv,MagickTrue); 308 image_info=AcquireImageInfo(); 309 (void) CopyMagickString(image_info->filename,argv[1],MaxTextExtent); 310 exception=AcquireExceptionInfo(); 311 contrast_image=ReadImage(image_info,exception); 312 if (contrast_image == (Image *) NULL) 313 ThrowImageException(contrast_image); 314 /* 315 Sigmoidal non-linearity contrast control. 316 */ 317 contrast_view=NewImageView(contrast_image); 318 if (contrast_view == (ImageView *) NULL) 319 ThrowImageException(contrast_image); 320 status=UpdateImageViewIterator(contrast_view,SigmoidalContrast,(void *) NULL); 321 if (status == MagickFalse) 322 ThrowImageException(contrast_image); 323 contrast_view=DestroyImageView(contrast_view); 324 /* 325 Write the image then destroy it. 326 */ 327 status=WriteImages(image_info,contrast_image,argv[2],exception); 328 if (status == MagickFalse) 329 ThrowImageException(contrast_image); 330 contrast_image=DestroyImage(contrast_image); 331 exception=DestroyExceptionInfo(exception); 332 image_info=DestroyImageInfo(image_info); 333 MagickCoreTerminus(); 334 return(0); 335}</code></pre> 336</div> 337 </div> 338 </main><!-- /.container --> 339 <footer class="magick-footer"> 340 <p><a href="../www/security-policy.html">Security</a> • 341 <a href="../www/architecture.html">Architecture</a> • 342 <a href="../www/links.html">Related</a> • 343 <a href="../www/sitemap.html">Sitemap</a> 344 345 <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> 346 347 <a href="http://pgp.mit.edu/pks/lookup?op=get&search=0x89AB63D48277377A">Public Key</a> • 348 <a href="../www/support.html">Donate</a> • 349 <a href="../www/https://imagemagick.org/script/contact.php">Contact Us</a> 350 <br/> 351 <small>© 1999-2019 ImageMagick Studio LLC</small></p> 352 </footer> 353 354 <!-- Javascript assets --> 355 <script src="assets/magick.js" crossorigin="anonymous"></script> 356 <script>window.jQuery || document.write('<script src="https://localhost/ajax/libs/jquery/3.3.1/jquery.min.js"><\/script>')</script> 357</body> 358</html> 359
