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>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 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> 92 93<ul> 94 <li><a href="api/magick.html">Initialize or Destroy the ImageMagick Environment</a></li> 95 <li><a href="api/constitute.html">Constitute an Image</a></li> 96 <li><a href="api/composite.html">Composite an Image</a></li> 97 <li><a href="api/image.html">Image Methods</a></li> 98 <li><a href="api/channel.html">Image Channel Methods</a></li> 99 <li><a href="api/color.html">Count the Colors in an Image</a></li> 100 <li><a href="api/colormap.html">Colormap Methods</a></li> 101 <li><a href="api/colorspace.html">Colorspace Methods</a></li> 102 <li><a href="api/distort.html">Image Distortions</a></li> 103 <li><a href="api/layer.html">Dealing with Image Layers</a></li> 104 <li><a href="api/profile.html">Dealing with Image Profiles</a></li> 105 <li><a href="api/quantize.html">Reduce the Number of Unique Colors in an Image</a></li> 106 <li><a href="api/histogram.html">Image Histograms</a></li> 107 <li><a href="api/segment.html">Segment an Image with Thresholding Fuzzy c-Means</a></li> 108 <li><a href="api/resize.html">Resize an Image</a></li> 109 <li><a href="api/transform.html">Transform an Image</a></li> 110 <li><a href="api/shear.html">Shear or Rotate an Image by an Arbitrary Angle</a></li> 111 <li><a href="api/enhance.html">Enhance an Image</a></li> 112 <li><a href="api/effect.html">Add an Effect</a></li> 113 <li><a href="api/morphology.html">Morphological Erosions, Dilations, Openings, and Closings</a></li> 114 <li><a href="api/fx.html">Add a Special Effect</a></li> 115 <li><a href="api/decorate.html">Decorate an Image</a></li> 116 <li><a href="api/attribute.html">Get/Set an Image Attribute</a></li> 117 <li><a href="api/property.html">Get/Set Image Properties</a></li> 118 <li><a href="api/statistic.html">Get Image Statistics</a></li> 119 <li><a href="api/feature.html">Get Image Features</a></li> 120 <li><a href="api/annotate.html">Annotate an Image</a></li> 121 <li><a href="api/paint.html">Paint on an Image</a></li> 122 <li><a href="api/draw.html">Draw on an Image</a></li> 123 <li><a href="api/montage.html">Create an Image Thumbnail</a></li> 124 <li><a href="api/fourier.html">Compute the discrete Fourier transform (DFT)</a></li> 125 <li><a href="api/compare.html">Compare an Image to a Reconstructed Image</a></li> 126 <li><a href="api/display.html">Interactively Display and Edit an Image</a></li> 127 <li><a href="api/animate.html">Interactively Animate an Image Sequence</a></li> 128 <li><a href="api/cipher.html">Convert to and from Cipher Pixels</a></li> 129 <li><a href="api/list.html">Working with Image Lists</a></li> 130 <li><a href="api/image-view.html">Image View Methods</a></li> 131 <li><a href="api/cache.html">Get or Set Image Pixels</a></li> 132 <li><a href="api/cache-view.html">Working with Cache Views</a></li> 133 <li><a href="api/stream.html">The Pixel FIFO</a></li> 134 <li><a href="api/blob.html">Read or Write Binary Large OBjects</a></li> 135 <li><a href="api/module.html">Loadable Modules</a></li> 136 <li><a href="api/signature.html">Compute a Message Digest for an Image</a></li> 137 <li><a href="api/registry.html">The Image Registry</a></li> 138 <li><a href="api/exception.html">Dealing with Exceptions</a></li> 139 <li><a href="api/memory.html">Memory Allocation</a></li> 140 <li><a href="api/resource.html">Monitor or Limit Resource Consumption</a></li> 141 <li><a href="api/monitor.html">Monitor the Progress of an Image Operation</a></li> 142 <li><a href="api/version.html">Get the Version and Copyrights</a></li> 143 <li><a href="api/mime.html">Mime Methods</a></li> 144 <li><a href="api/deprecate.html">Deprecated Methods</a></li> 145 <li><a href="../www/exception.html">Error and Warning Codes</a></li> 146</ul> 147 148<p>After you write your MagickCore program, compile it like this:</p> 149 150<pre class="highlight"><code>cc -o core core.c `pkg-config --cflags --libs MagickWand` 151</code></pre> 152 153<p>Set the <code>PKG_CONFIG_PATH</code> environment variable if ImageMagick is not in your default system path:</p> 154 155<pre class="highlight"><code>export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig 156</code></pre> 157 158<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> 159 160<pre class="pre-scrollable"><code>#include <stdio.h> 161#include <stdlib.h> 162#include <string.h> 163#include <time.h> 164#include <MagickCore/MagickCore.h> 165 166int main(int argc,char **argv) 167{ 168 ExceptionInfo 169 *exception; 170 171 Image 172 *image, 173 *images, 174 *resize_image, 175 *thumbnails; 176 177 ImageInfo 178 *image_info; 179 180 if (argc != 3) 181 { 182 (void) fprintf(stdout,"Usage: %s image thumbnail\n",argv[0]); 183 exit(0); 184 } 185 /* 186 Initialize the image info structure and read an image. 187 */ 188 MagickCoreGenesis(*argv,MagickTrue); 189 exception=AcquireExceptionInfo(); 190 image_info=CloneImageInfo((ImageInfo *) NULL); 191 (void) strcpy(image_info->filename,argv[1]); 192 images=ReadImage(image_info,exception); 193 if (exception->severity != UndefinedException) 194 CatchException(exception); 195 if (images == (Image *) NULL) 196 exit(1); 197 /* 198 Convert the image to a thumbnail. 199 */ 200 thumbnails=NewImageList(); 201 while ((image=RemoveFirstImageFromList(&images)) != (Image *) NULL) 202 { 203 resize_image=ResizeImage(image,106,80,LanczosFilter,exception); 204 if (resize_image == (Image *) NULL) 205 MagickError(exception->severity,exception->reason,exception->description); 206 (void) AppendImageToList(&thumbnails,resize_image); 207 DestroyImage(image); 208 } 209 /* 210 Write the image thumbnail. 211 */ 212 (void) strcpy(thumbnails->filename,argv[2]); 213 WriteImage(image_info,thumbnails,exception); 214 /* 215 Destroy the image thumbnail and exit. 216 */ 217 thumbnails=DestroyImageList(thumbnails); 218 image_info=DestroyImageInfo(image_info); 219 exception=DestroyExceptionInfo(exception); 220 MagickCoreTerminus(); 221 return(0); 222}</code></pre> 223<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> 224 225<pre class="pre-scrollable"><code>#include <stdio.h> 226#include <stdlib.h> 227#include <math.h> 228#include <MagickCore/MagickCore.h> 229 230static MagickBooleanType SigmoidalContrast(ImageView *contrast_view, 231 const ssize_t y,const int id,void *context) 232{ 233#define QuantumScale ((MagickRealType) 1.0/(MagickRealType) QuantumRange) 234#define SigmoidalContrast(x) \ 235 (QuantumRange*(1.0/(1+exp(10.0*(0.5-QuantumScale*x)))-0.0066928509)*1.0092503) 236 237 RectangleInfo 238 extent; 239 240 register IndexPacket 241 *indexes; 242 243 register PixelPacket 244 *pixels; 245 246 register ssize_t 247 x; 248 249 extent=GetImageViewExtent(contrast_view); 250 pixels=GetImageViewAuthenticPixels(contrast_view); 251 for (x=0; x < (ssize_t) (extent.width-extent.x); x++) 252 { 253 SetPixelRed(pixels,RoundToQuantum(SigmoidalContrast(GetPixelRed(pixels))); 254 SetPixelGreen(pixels,RoundToQuantum(SigmoidalContrast(GetPixelGreen(pixels))); 255 SetPixelBlue(pixels,RoundToQuantum(SigmoidalContrast(GetPixelBlue(pixels))); 256 SetPixelOpacity(pixels,RoundToQuantum(SigmoidalContrast(GetPixelOpacity(pixels))); 257 pixels++; 258 } 259 indexes=GetImageViewAuthenticIndexes(contrast_view); 260 if (indexes != (IndexPacket *) NULL) 261 for (x=0; x < (ssize_t) (extent.width-extent.x); x++) 262 SetPixelIndex(indexes+x,RoundToQuantum(SigmoidalContrast(GetPixelIndex(indexes+x)))); 263 return(MagickTrue); 264} 265 266int main(int argc,char **argv) 267{ 268#define ThrowImageException(image) \ 269{ \ 270 \ 271 CatchException(exception); \ 272 if (contrast_image != (Image *) NULL) \ 273 contrast_image=DestroyImage(contrast_image); \ 274 exit(-1); \ 275} 276#define ThrowViewException(view) \ 277{ \ 278 char \ 279 *description; \ 280 \ 281 ExceptionType \ 282 severity; \ 283 \ 284 description=GetImageViewException(view,&severity); \ 285 (void) fprintf(stderr,"%s %s %lu %s\n",GetMagickModule(),description); \ 286 description=DestroyString(description); \ 287 exit(-1); \ 288} 289 290 ExceptionInfo 291 *exception; 292 293 Image 294 *contrast_image; 295 296 ImageInfo 297 *image_info; 298 299 ImageView 300 *contrast_view; 301 302 MagickBooleanType 303 status; 304 305 if (argc != 3) 306 { 307 (void) fprintf(stdout,"Usage: %s image sigmoidal-image\n",argv[0]); 308 exit(0); 309 } 310 /* 311 Read an image. 312 */ 313 MagickCoreGenesis(*argv,MagickTrue); 314 image_info=AcquireImageInfo(); 315 (void) CopyMagickString(image_info->filename,argv[1],MaxTextExtent); 316 exception=AcquireExceptionInfo(); 317 contrast_image=ReadImage(image_info,exception); 318 if (contrast_image == (Image *) NULL) 319 ThrowImageException(contrast_image); 320 /* 321 Sigmoidal non-linearity contrast control. 322 */ 323 contrast_view=NewImageView(contrast_image); 324 if (contrast_view == (ImageView *) NULL) 325 ThrowImageException(contrast_image); 326 status=UpdateImageViewIterator(contrast_view,SigmoidalContrast,(void *) NULL); 327 if (status == MagickFalse) 328 ThrowImageException(contrast_image); 329 contrast_view=DestroyImageView(contrast_view); 330 /* 331 Write the image then destroy it. 332 */ 333 status=WriteImages(image_info,contrast_image,argv[2],exception); 334 if (status == MagickFalse) 335 ThrowImageException(contrast_image); 336 contrast_image=DestroyImage(contrast_image); 337 exception=DestroyExceptionInfo(exception); 338 image_info=DestroyImageInfo(image_info); 339 MagickCoreTerminus(); 340 return(0); 341}</code></pre> 342</div> 343 </div> 344 </main><!-- /.container --> 345 <footer class="magick-footer"> 346 <p><a href="security-policy.html">Security</a> • 347 <a href="architecture.html">Architecture</a> 348 349 <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> 350 351 <a href="links.html">Related</a> • 352 <a href="sitemap.html">Sitemap</a> 353 <br/> 354 <a href="support.html">Donate</a> • 355 <a href="http://pgp.mit.edu/pks/lookup?op=get&search=0x89AB63D48277377A">Public Key</a> • 356 <a href="https://imagemagick.org/script/contact.php">Contact Us</a> 357 <br/> 358 <small>© 1999-2020 ImageMagick Studio LLC</small></p> 359 </footer> 360 361 <!-- Javascript assets --> 362 <script src="assets/magick.js" crossorigin="anonymous"></script> 363 <script>window.jQuery || document.write('<script src="https://localhost/ajax/libs/jquery/3.4.1/jquery.min.js"><\/script>')</script> 364</body> 365</html> 366<!-- Magick Cache 5th January 2020 09:22 -->
