1 2 3 4 5 <!DOCTYPE html> 6 <html lang="en"> 7 <head> 8 <title>ImageMagick: MagickCore, C API for ImageMagick: Enhance an Image</title> 9 <meta charset="utf-8" /> 10 <meta http-equiv="X-UA-Compatible" content="IE=edge" /> 11 <meta name="viewport" content="width=device-width, initial-scale=1" /> 12 <meta http-equiv="content-type" content="text/html; charset=utf-8"/> 13 <meta name="application-name" content="ImageMagick"/> 14 <meta name="description" content="ImageMagick is a software suite to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, JPEG-2000, GIF, WebP, Postscript, PDF, and SVG. Use ImageMagick to resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bzier curves."/> 15 <meta name="application-url" content="http://www.imagemagick.org"/> 16 <meta name="generator" content="PHP"/> 17 <meta name="keywords" content="magickcore, c, api, for, imagemagick:, enhance, an, image, ImageMagick, PerlMagick, image processing, image, photo, software, Magick++, OpenMP, convert"/> 18 <meta name="rating" content="GENERAL"/> 19 <meta name="robots" content="INDEX, FOLLOW"/> 20 <meta name="generator" content="ImageMagick Studio LLC"/> 21 <meta name="author" content="ImageMagick Studio LLC"/> 22 <meta name="revisit-after" content="2 DAYS"/> 23 <meta name="resource-type" content="document"/> 24 <meta name="copyright" content="Copyright (c) 1999-2016 ImageMagick Studio LLC"/> 25 <meta name="distribution" content="Global"/> 26 <meta name="magick-serial" content="P131-S030410-R485315270133-P82224-A6668-G1245-1"/> 27 <meta name="google-site-verification" content="_bMOCDpkx9ZAzBwb2kF3PRHbfUUdFj2uO8Jd1AXArz4" /> 28 <link rel="icon" href="../images/wand.png"/> 29 <link rel="shortcut icon" href="../images/wand.ico"/> 30 <link rel="stylesheet" type="text/css" href="http://fonts.googleapis.com/css?family=Roboto:900,400,400italic,700,700italic,300,300italic|Open+Sans:300italic,400italic,700italic,300,400,600,700"> 31 <link rel="stylesheet" href="../css/magick.html"/> 32 </head> 33 <body> 34 <div class="main"> 35 <div class="magick-masthead"> 36 <div class="container"> 37 <script async="async" src="http://localhost/pagead/js/adsbygoogle.js"></script> <ins class="adsbygoogle" 38 style="display:block" 39 data-ad-client="ca-pub-3129977114552745" 40 data-ad-slot="6345125851" 41 data-ad-format="auto"></ins> 42 <script> 43 (adsbygoogle = window.adsbygoogle || []).push({}); 44 </script> 45 <nav class="magick-nav"> 46 <a class="magick-nav-item " href="../index.html">Home</a> 47 <a class="magick-nav-item " href="../binary-releases.html">Download</a> 48 <a class="magick-nav-item " href="../command-line-tools.html">Tools</a> 49 <a class="magick-nav-item " href="../command-line-processing.html">Command-line</a> 50 <a class="magick-nav-item " href="../resources.html">Resources</a> 51 <a class="magick-nav-item " href="api.html">Develop</a> 52 <a class="magick-nav-item " href="http://www.imagemagick.org/script/search.php">Search</a> 53 <a class="magick-nav-item pull-right" href="https://www.imagemagick.org/discourse-server/">Community</a> 54 </nav> 55 </div> 56 </div> 57 <div class="container"> 58 <div class="magick-header"> 59 <p class="text-center"><a href="enhance.html#AutoGammaImage">AutoGammaImage</a> • <a href="enhance.html#AutoLevelImage">AutoLevelImage</a> • <a href="enhance.html#BrightnessContrastImage">BrightnessContrastImage</a> • <a href="enhance.html#ClutImage">ClutImage</a> • <a href="enhance.html#ColorDecisionListImage">ColorDecisionListImage</a> • <a href="enhance.html#ContrastImage">ContrastImage</a> • <a href="enhance.html#ContrastStretchImage">ContrastStretchImage</a> • <a href="enhance.html#EnhanceImage">EnhanceImage</a> • <a href="enhance.html#EqualizeImage">EqualizeImage</a> • <a href="enhance.html#GammaImage">GammaImage</a> • <a href="enhance.html#GrayscaleImage">GrayscaleImage</a> • <a href="enhance.html#HaldClutImage">HaldClutImage</a> • <a href="enhance.html#LevelImage">LevelImage</a> • <a href="enhance.html#LevelizeImage">LevelizeImage</a> • <a href="enhance.html#LevelImageColors">LevelImageColors</a> • <a href="enhance.html#LinearStretchImage">LinearStretchImage</a> • <a href="enhance.html#ModulateImage">ModulateImage</a> • <a href="enhance.html#NegateImage">NegateImage</a> • <a href="enhance.html#The NormalizeImage">The NormalizeImage</a> • <a href="enhance.html#SigmoidalContrastImage">SigmoidalContrastImage</a></p> 60 61 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="AutoGammaImage">AutoGammaImage</a></h2> 62 63 <p>AutoGammaImage() extract the 'mean' from the image and adjust the image to try make set its gamma appropriatally.</p> 64 65 <p>The format of the AutoGammaImage method is:</p> 66 67 <pre class="text"> 68 MagickBooleanType AutoGammaImage(Image *image,ExceptionInfo *exception) 69 </pre> 70 71 <p>A description of each parameter follows:</p> 72 73 <dd> 74 </dd> 75 76 <dd> </dd> 77 <dl class="dl-horizontal"> 78 <dt>image</dt> 79 <dd>The image to auto-level </dd> 80 81 <dd> </dd> 82 <dt>exception</dt> 83 <dd>return any errors or warnings in this structure. </dd> 84 85 <dd> </dd> 86 </dl> 87 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="AutoLevelImage">AutoLevelImage</a></h2> 88 89 <p>AutoLevelImage() adjusts the levels of a particular image channel by scaling the minimum and maximum values to the full quantum range.</p> 90 91 <p>The format of the LevelImage method is:</p> 92 93 <pre class="text"> 94 MagickBooleanType AutoLevelImage(Image *image,ExceptionInfo *exception) 95 </pre> 96 97 <p>A description of each parameter follows:</p> 98 99 <dd> 100 </dd> 101 102 <dd> </dd> 103 <dl class="dl-horizontal"> 104 <dt>image</dt> 105 <dd>The image to auto-level </dd> 106 107 <dd> </dd> 108 <dt>exception</dt> 109 <dd>return any errors or warnings in this structure. </dd> 110 111 <dd> </dd> 112 </dl> 113 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="BrightnessContrastImage">BrightnessContrastImage</a></h2> 114 115 <p>BrightnessContrastImage() changes the brightness and/or contrast of an image. It converts the brightness and contrast parameters into slope and intercept and calls a polynomical function to apply to the image.</p> 116 117 <p>The format of the BrightnessContrastImage method is:</p> 118 119 <pre class="text"> 120 MagickBooleanType BrightnessContrastImage(Image *image, 121 const double brightness,const double contrast,ExceptionInfo *exception) 122 </pre> 123 124 <p>A description of each parameter follows:</p> 125 126 <dd> 127 </dd> 128 129 <dd> </dd> 130 <dl class="dl-horizontal"> 131 <dt>image</dt> 132 <dd>the image. </dd> 133 134 <dd> </dd> 135 <dt>brightness</dt> 136 <dd>the brightness percent (-100 .. 100). </dd> 137 138 <dd> </dd> 139 <dt>contrast</dt> 140 <dd>the contrast percent (-100 .. 100). </dd> 141 142 <dd> </dd> 143 <dt>exception</dt> 144 <dd>return any errors or warnings in this structure. </dd> 145 146 <dd> </dd> 147 </dl> 148 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="ClutImage">ClutImage</a></h2> 149 150 <p>ClutImage() replaces each color value in the given image, by using it as an index to lookup a replacement color value in a Color Look UP Table in the form of an image. The values are extracted along a diagonal of the CLUT image so either a horizontal or vertial gradient image can be used.</p> 151 152 <p>Typically this is used to either re-color a gray-scale image according to a color gradient in the CLUT image, or to perform a freeform histogram (level) adjustment according to the (typically gray-scale) gradient in the CLUT image.</p> 153 154 <p>When the 'channel' mask includes the matte/alpha transparency channel but one image has no such channel it is assumed that that image is a simple gray-scale image that will effect the alpha channel values, either for gray-scale coloring (with transparent or semi-transparent colors), or a histogram adjustment of existing alpha channel values. If both images have matte channels, direct and normal indexing is applied, which is rarely used.</p> 155 156 <p>The format of the ClutImage method is:</p> 157 158 <pre class="text"> 159 MagickBooleanType ClutImage(Image *image,Image *clut_image, 160 const PixelInterpolateMethod method,ExceptionInfo *exception) 161 </pre> 162 163 <p>A description of each parameter follows:</p> 164 165 <dd> 166 </dd> 167 168 <dd> </dd> 169 <dl class="dl-horizontal"> 170 <dt>image</dt> 171 <dd>the image, which is replaced by indexed CLUT values </dd> 172 173 <dd> </dd> 174 <dt>clut_image</dt> 175 <dd>the color lookup table image for replacement color values. </dd> 176 177 <dd> </dd> 178 <dt>method</dt> 179 <dd>the pixel interpolation method. </dd> 180 181 <dd> </dd> 182 <dt>exception</dt> 183 <dd>return any errors or warnings in this structure. </dd> 184 185 <dd> </dd> 186 </dl> 187 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="ColorDecisionListImage">ColorDecisionListImage</a></h2> 188 189 <p>ColorDecisionListImage() accepts a lightweight Color Correction Collection (CCC) file which solely contains one or more color corrections and applies the correction to the image. Here is a sample CCC file:</p> 190 191 <pre class="text"> 192 <ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"> 193 <ColorCorrection id="cc03345"> 194 <SOPNode> 195 <Slope> 0.9 1.2 0.5 </Slope> 196 <Offset> 0.4 -0.5 0.6 </Offset> 197 <Power> 1.0 0.8 1.5 </Power> 198 </SOPNode> 199 <SATNode> 200 <Saturation> 0.85 </Saturation> 201 </SATNode> 202 </ColorCorrection> 203 </ColorCorrectionCollection> 204 </pre> 205 206 <p>which includes the slop, offset, and power for each of the RGB channels as well as the saturation.</p> 207 208 <p>The format of the ColorDecisionListImage method is:</p> 209 210 <pre class="text"> 211 MagickBooleanType ColorDecisionListImage(Image *image, 212 const char *color_correction_collection,ExceptionInfo *exception) 213 </pre> 214 215 <p>A description of each parameter follows:</p> 216 217 <dd> 218 </dd> 219 220 <dd> </dd> 221 <dl class="dl-horizontal"> 222 <dt>image</dt> 223 <dd>the image. </dd> 224 225 <dd> </dd> 226 <dt>color_correction_collection</dt> 227 <dd>the color correction collection in XML. </dd> 228 229 <dd> </dd> 230 <dt>exception</dt> 231 <dd>return any errors or warnings in this structure. </dd> 232 233 <dd> </dd> 234 </dl> 235 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="ContrastImage">ContrastImage</a></h2> 236 237 <p>ContrastImage() enhances the intensity differences between the lighter and darker elements of the image. Set sharpen to a MagickTrue to increase the image contrast otherwise the contrast is reduced.</p> 238 239 <p>The format of the ContrastImage method is:</p> 240 241 <pre class="text"> 242 MagickBooleanType ContrastImage(Image *image, 243 const MagickBooleanType sharpen,ExceptionInfo *exception) 244 </pre> 245 246 <p>A description of each parameter follows:</p> 247 248 <dd> 249 </dd> 250 251 <dd> </dd> 252 <dl class="dl-horizontal"> 253 <dt>image</dt> 254 <dd>the image. </dd> 255 256 <dd> </dd> 257 <dt>sharpen</dt> 258 <dd>Increase or decrease image contrast. </dd> 259 260 <dd> </dd> 261 <dt>exception</dt> 262 <dd>return any errors or warnings in this structure. </dd> 263 264 <dd> </dd> 265 </dl> 266 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="ContrastStretchImage">ContrastStretchImage</a></h2> 267 268 <p>ContrastStretchImage() is a simple image enhancement technique that attempts to improve the contrast in an image by 'stretching' the range of intensity values it contains to span a desired range of values. It differs from the more sophisticated histogram equalization in that it can only apply a linear scaling function to the image pixel values. As a result the 'enhancement' is less harsh.</p> 269 270 <p>The format of the ContrastStretchImage method is:</p> 271 272 <pre class="text"> 273 MagickBooleanType ContrastStretchImage(Image *image, 274 const char *levels,ExceptionInfo *exception) 275 </pre> 276 277 <p>A description of each parameter follows:</p> 278 279 <dd> 280 </dd> 281 282 <dd> </dd> 283 <dl class="dl-horizontal"> 284 <dt>image</dt> 285 <dd>the image. </dd> 286 287 <dd> </dd> 288 <dt>black_point</dt> 289 <dd>the black point. </dd> 290 291 <dd> </dd> 292 <dt>white_point</dt> 293 <dd>the white point. </dd> 294 295 <dd> </dd> 296 <dt>levels</dt> 297 <dd>Specify the levels where the black and white points have the range of 0 to number-of-pixels (e.g. 1, 10x90, etc.). </dd> 298 299 <dd> </dd> 300 <dt>exception</dt> 301 <dd>return any errors or warnings in this structure. </dd> 302 303 <dd> </dd> 304 </dl> 305 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="EnhanceImage">EnhanceImage</a></h2> 306 307 <p>EnhanceImage() applies a digital filter that improves the quality of a noisy image.</p> 308 309 <p>The format of the EnhanceImage method is:</p> 310 311 <pre class="text"> 312 Image *EnhanceImage(const Image *image,ExceptionInfo *exception) 313 </pre> 314 315 <p>A description of each parameter follows:</p> 316 317 <dd> 318 </dd> 319 320 <dd> </dd> 321 <dl class="dl-horizontal"> 322 <dt>image</dt> 323 <dd>the image. </dd> 324 325 <dd> </dd> 326 <dt>exception</dt> 327 <dd>return any errors or warnings in this structure. </dd> 328 329 <dd> </dd> 330 </dl> 331 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="EqualizeImage">EqualizeImage</a></h2> 332 333 <p>EqualizeImage() applies a histogram equalization to the image.</p> 334 335 <p>The format of the EqualizeImage method is:</p> 336 337 <pre class="text"> 338 MagickBooleanType EqualizeImage(Image *image,ExceptionInfo *exception) 339 </pre> 340 341 <p>A description of each parameter follows:</p> 342 343 <dd> 344 </dd> 345 346 <dd> </dd> 347 <dl class="dl-horizontal"> 348 <dt>image</dt> 349 <dd>the image. </dd> 350 351 <dd> </dd> 352 <dt>exception</dt> 353 <dd>return any errors or warnings in this structure. </dd> 354 355 <dd> </dd> 356 </dl> 357 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="GammaImage">GammaImage</a></h2> 358 359 <p>GammaImage() gamma-corrects a particular image channel. The same image viewed on different devices will have perceptual differences in the way the image's intensities are represented on the screen. Specify individual gamma levels for the red, green, and blue channels, or adjust all three with the gamma parameter. Values typically range from 0.8 to 2.3.</p> 360 361 <p>You can also reduce the influence of a particular channel with a gamma value of 0.</p> 362 363 <p>The format of the GammaImage method is:</p> 364 365 <pre class="text"> 366 MagickBooleanType GammaImage(Image *image,const double gamma, 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 image. </dd> 379 380 <dd> </dd> 381 <dt>level</dt> 382 <dd>the image gamma as a string (e.g. 1.6,1.2,1.0). </dd> 383 384 <dd> </dd> 385 <dt>gamma</dt> 386 <dd>the image gamma. </dd> 387 388 <dd> </dd> 389 </dl> 390 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="GrayscaleImage">GrayscaleImage</a></h2> 391 392 <p>GrayscaleImage() converts the image to grayscale.</p> 393 394 <p>The format of the GrayscaleImage method is:</p> 395 396 <pre class="text"> 397 MagickBooleanType GrayscaleImage(Image *image, 398 const PixelIntensityMethod method ,ExceptionInfo *exception) 399 </pre> 400 401 <p>A description of each parameter follows:</p> 402 403 <dd> 404 </dd> 405 406 <dd> </dd> 407 <dl class="dl-horizontal"> 408 <dt>image</dt> 409 <dd>the image. </dd> 410 411 <dd> </dd> 412 <dt>method</dt> 413 <dd>the pixel intensity method. </dd> 414 415 <dd> </dd> 416 <dt>exception</dt> 417 <dd>return any errors or warnings in this structure. </dd> 418 419 <dd> </dd> 420 </dl> 421 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="HaldClutImage">HaldClutImage</a></h2> 422 423 <p>HaldClutImage() applies a Hald color lookup table to the image. A Hald color lookup table is a 3-dimensional color cube mapped to 2 dimensions. Create it with the HALD coder. You can apply any color transformation to the Hald image and then use this method to apply the transform to the image.</p> 424 425 <p>The format of the HaldClutImage method is:</p> 426 427 <pre class="text"> 428 MagickBooleanType HaldClutImage(Image *image,Image *hald_image, 429 ExceptionInfo *exception) 430 </pre> 431 432 <p>A description of each parameter follows:</p> 433 434 <dd> 435 </dd> 436 437 <dd> </dd> 438 <dl class="dl-horizontal"> 439 <dt>image</dt> 440 <dd>the image, which is replaced by indexed CLUT values </dd> 441 442 <dd> </dd> 443 <dt>hald_image</dt> 444 <dd>the color lookup table image for replacement color values. </dd> 445 446 <dd> </dd> 447 <dt>exception</dt> 448 <dd>return any errors or warnings in this structure. </dd> 449 450 <dd> </dd> 451 </dl> 452 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="LevelImage">LevelImage</a></h2> 453 454 <p>LevelImage() adjusts the levels of a particular image channel by scaling the colors falling between specified white and black points to the full available quantum range.</p> 455 456 <p>The parameters provided represent the black, and white points. The black point specifies the darkest color in the image. Colors darker than the black point are set to zero. White point specifies the lightest color in the image. Colors brighter than the white point are set to the maximum quantum value.</p> 457 458 <p>If a '!' flag is given, map black and white colors to the given levels rather than mapping those levels to black and white. See LevelizeImage() below.</p> 459 460 <p>Gamma specifies a gamma correction to apply to the image.</p> 461 462 <p>The format of the LevelImage method is:</p> 463 464 <pre class="text"> 465 MagickBooleanType LevelImage(Image *image,const double black_point, 466 const double white_point,const double gamma,ExceptionInfo *exception) 467 </pre> 468 469 <p>A description of each parameter follows:</p> 470 471 <dd> 472 </dd> 473 474 <dd> </dd> 475 <dl class="dl-horizontal"> 476 <dt>image</dt> 477 <dd>the image. </dd> 478 479 <dd> </dd> 480 <dt>black_point</dt> 481 <dd>The level to map zero (black) to. </dd> 482 483 <dd> </dd> 484 <dt>white_point</dt> 485 <dd>The level to map QuantumRange (white) to. </dd> 486 487 <dd> </dd> 488 <dt>exception</dt> 489 <dd>return any errors or warnings in this structure. </dd> 490 491 <dd> </dd> 492 </dl> 493 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="LevelizeImage">LevelizeImage</a></h2> 494 495 <p>LevelizeImage() applies the reversed LevelImage() operation to just the specific channels specified. It compresses the full range of color values, so that they lie between the given black and white points. Gamma is applied before the values are mapped.</p> 496 497 <p>LevelizeImage() can be called with by using a +level command line API option, or using a '!' on a -level or LevelImage() geometry string.</p> 498 499 <p>It can be used to de-contrast a greyscale image to the exact levels specified. Or by using specific levels for each channel of an image you can convert a gray-scale image to any linear color gradient, according to those levels.</p> 500 501 <p>The format of the LevelizeImage method is:</p> 502 503 <pre class="text"> 504 MagickBooleanType LevelizeImage(Image *image,const double black_point, 505 const double white_point,const double gamma,ExceptionInfo *exception) 506 </pre> 507 508 <p>A description of each parameter follows:</p> 509 510 <dd> 511 </dd> 512 513 <dd> </dd> 514 <dl class="dl-horizontal"> 515 <dt>image</dt> 516 <dd>the image. </dd> 517 518 <dd> </dd> 519 <dt>black_point</dt> 520 <dd>The level to map zero (black) to. </dd> 521 522 <dd> </dd> 523 <dt>white_point</dt> 524 <dd>The level to map QuantumRange (white) to. </dd> 525 526 <dd> </dd> 527 <dt>gamma</dt> 528 <dd>adjust gamma by this factor before mapping values. </dd> 529 530 <dd> </dd> 531 <dt>exception</dt> 532 <dd>return any errors or warnings in this structure. </dd> 533 534 <dd> </dd> 535 </dl> 536 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="LevelImageColors">LevelImageColors</a></h2> 537 538 <p>LevelImageColors() maps the given color to "black" and "white" values, linearly spreading out the colors, and level values on a channel by channel bases, as per LevelImage(). The given colors allows you to specify different level ranges for each of the color channels separately.</p> 539 540 <p>If the boolean 'invert' is set true the image values will modifyed in the reverse direction. That is any existing "black" and "white" colors in the image will become the color values given, with all other values compressed appropriatally. This effectivally maps a greyscale gradient into the given color gradient.</p> 541 542 <p>The format of the LevelImageColors method is:</p> 543 544 <pre class="text"> 545 MagickBooleanType LevelImageColors(Image *image, 546 const PixelInfo *black_color,const PixelInfo *white_color, 547 const MagickBooleanType invert,ExceptionInfo *exception) 548 </pre> 549 550 <p>A description of each parameter follows:</p> 551 552 <dd> 553 </dd> 554 555 <dd> </dd> 556 <dl class="dl-horizontal"> 557 <dt>image</dt> 558 <dd>the image. </dd> 559 560 <dd> </dd> 561 <dt>black_color</dt> 562 <dd>The color to map black to/from </dd> 563 564 <dd> </dd> 565 <dt>white_point</dt> 566 <dd>The color to map white to/from </dd> 567 568 <dd> </dd> 569 <dt>invert</dt> 570 <dd>if true map the colors (levelize), rather than from (level) </dd> 571 572 <dd> </dd> 573 <dt>exception</dt> 574 <dd>return any errors or warnings in this structure. </dd> 575 576 <dd> </dd> 577 </dl> 578 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="LinearStretchImage">LinearStretchImage</a></h2> 579 580 <p>LinearStretchImage() discards any pixels below the black point and above the white point and levels the remaining pixels.</p> 581 582 <p>The format of the LinearStretchImage method is:</p> 583 584 <pre class="text"> 585 MagickBooleanType LinearStretchImage(Image *image, 586 const double black_point,const double white_point, 587 ExceptionInfo *exception) 588 </pre> 589 590 <p>A description of each parameter follows:</p> 591 592 <dd> 593 </dd> 594 595 <dd> </dd> 596 <dl class="dl-horizontal"> 597 <dt>image</dt> 598 <dd>the image. </dd> 599 600 <dd> </dd> 601 <dt>black_point</dt> 602 <dd>the black point. </dd> 603 604 <dd> </dd> 605 <dt>white_point</dt> 606 <dd>the white point. </dd> 607 608 <dd> </dd> 609 <dt>exception</dt> 610 <dd>return any errors or warnings in this structure. </dd> 611 612 <dd> </dd> 613 </dl> 614 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="ModulateImage">ModulateImage</a></h2> 615 616 <p>ModulateImage() lets you control the brightness, saturation, and hue of an image. Modulate represents the brightness, saturation, and hue as one parameter (e.g. 90,150,100). If the image colorspace is HSL, the modulation is lightness, saturation, and hue. For HWB, use blackness, whiteness, and hue. And for HCL, use chrome, luma, and hue.</p> 617 618 <p>The format of the ModulateImage method is:</p> 619 620 <pre class="text"> 621 MagickBooleanType ModulateImage(Image *image,const char *modulate, 622 ExceptionInfo *exception) 623 </pre> 624 625 <p>A description of each parameter follows:</p> 626 627 <dd> 628 </dd> 629 630 <dd> </dd> 631 <dl class="dl-horizontal"> 632 <dt>image</dt> 633 <dd>the image. </dd> 634 635 <dd> </dd> 636 <dt>modulate</dt> 637 <dd>Define the percent change in brightness, saturation, and hue. </dd> 638 639 <dd> </dd> 640 <dt>exception</dt> 641 <dd>return any errors or warnings in this structure. </dd> 642 643 <dd> </dd> 644 </dl> 645 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="NegateImage">NegateImage</a></h2> 646 647 <p>NegateImage() negates the colors in the reference image. The grayscale option means that only grayscale values within the image are negated.</p> 648 649 <p>The format of the NegateImage method is:</p> 650 651 <pre class="text"> 652 MagickBooleanType NegateImage(Image *image, 653 const MagickBooleanType grayscale,ExceptionInfo *exception) 654 </pre> 655 656 <p>A description of each parameter follows:</p> 657 658 <dd> 659 </dd> 660 661 <dd> </dd> 662 <dl class="dl-horizontal"> 663 <dt>image</dt> 664 <dd>the image. </dd> 665 666 <dd> </dd> 667 <dt>grayscale</dt> 668 <dd>If MagickTrue, only negate grayscale pixels within the image. </dd> 669 670 <dd> </dd> 671 <dt>exception</dt> 672 <dd>return any errors or warnings in this structure. </dd> 673 674 <dd> </dd> 675 </dl> 676 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="The_NormalizeImage">The NormalizeImage</a></h2> 677 678 <p>The NormalizeImage() method enhances the contrast of a color image by mapping the darkest 2 percent of all pixel to black and the brightest 1 percent to white.</p> 679 680 <p>The format of the NormalizeImage method is:</p> 681 682 <pre class="text"> 683 MagickBooleanType NormalizeImage(Image *image,ExceptionInfo *exception) 684 </pre> 685 686 <p>A description of each parameter follows:</p> 687 688 <dd> 689 </dd> 690 691 <dd> </dd> 692 <dl class="dl-horizontal"> 693 <dt>image</dt> 694 <dd>the image. </dd> 695 696 <dd> </dd> 697 <dt>exception</dt> 698 <dd>return any errors or warnings in this structure. </dd> 699 700 <dd> </dd> 701 </dl> 702 <h2><a href="http://www.imagemagick.org/api/MagickCore/enhance_8c.html" id="SigmoidalContrastImage">SigmoidalContrastImage</a></h2> 703 704 <p>SigmoidalContrastImage() adjusts the contrast of an image with a non-linear sigmoidal contrast algorithm. Increase the contrast of the image using a sigmoidal transfer function without saturating highlights or shadows. Contrast indicates how much to increase the contrast (0 is none; 3 is typical; 20 is pushing it); mid-point indicates where midtones fall in the resultant image (0 is white; 50 is middle-gray; 100 is black). Set sharpen to MagickTrue to increase the image contrast otherwise the contrast is reduced.</p> 705 706 <p>The format of the SigmoidalContrastImage method is:</p> 707 708 <pre class="text"> 709 MagickBooleanType SigmoidalContrastImage(Image *image, 710 const MagickBooleanType sharpen,const char *levels, 711 ExceptionInfo *exception) 712 </pre> 713 714 <p>A description of each parameter follows:</p> 715 716 <dd> 717 </dd> 718 719 <dd> </dd> 720 <dl class="dl-horizontal"> 721 <dt>image</dt> 722 <dd>the image. </dd> 723 724 <dd> </dd> 725 <dt>sharpen</dt> 726 <dd>Increase or decrease image contrast. </dd> 727 728 <dd> </dd> 729 <dt>contrast</dt> 730 <dd>strength of the contrast, the larger the number the more 'threshold-like' it becomes. </dd> 731 732 <dd> </dd> 733 <dt>midpoint</dt> 734 <dd>midpoint of the function as a color value 0 to QuantumRange. </dd> 735 736 <dd> </dd> 737 <dt>exception</dt> 738 <dd>return any errors or warnings in this structure. </dd> 739 740 <dd> </dd> 741 </dl> 742 </div> 743 <footer class="magick-footer"> 744 <p><a href="../support.html">Donate</a> 745 <a href="../sitemap.html">Sitemap</a> 746 <a href="../links.html">Related</a> 747 <a href="../architecture.html">Architecture</a> 748 </p> 749 <p><a href="enhance.html#">Back to top</a> 750 <a href="http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x89AB63D48277377A">Public Key</a> 751 <a href="http://www.imagemagick.org/script/contact.php">Contact Us</a></p> 752 <p><small> 1999-2016 ImageMagick Studio LLC</small></p> 753 </footer> 754 </div><!-- /.container --> 755 756 <script src="https://localhost/ajax/libs/jquery/1.11.3/jquery.min.js"></script> 757 <script src="../js/magick.html"></script> 758 </div> 759 </body> 760 </html> 761