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223 <h1>Module effect Methods</h1>
224 <p class="navigation-index">[<a href="effect.html#AdaptiveBlurImage">AdaptiveBlurImage</a> • <a href="effect.html#AdaptiveSharpenImage">AdaptiveSharpenImage</a> • <a href="effect.html#BlurImage">BlurImage</a> • <a href="effect.html#ConvolveImage">ConvolveImage</a> • <a href="effect.html#DespeckleImage">DespeckleImage</a> • <a href="effect.html#EdgeImage">EdgeImage</a> • <a href="effect.html#EmbossImage">EmbossImage</a> • <a href="effect.html#FilterImage">FilterImage</a> • <a href="effect.html#GaussianBlurImage">GaussianBlurImage</a> • <a href="effect.html#MotionBlurImage">MotionBlurImage</a> • <a href="effect.html#PreviewImage">PreviewImage</a> • <a href="effect.html#RadialBlurImage">RadialBlurImage</a> • <a href="effect.html#SelectiveBlurImage">SelectiveBlurImage</a> • <a href="effect.html#ShadeImage">ShadeImage</a> • <a href="effect.html#SharpenImage">SharpenImage</a> • <a href="effect.html#SpreadImage">SpreadImage</a> • <a href="effect.html#UnsharpMaskImage">UnsharpMaskImage</a>]</p>
226 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="AdaptiveBlurImage">AdaptiveBlurImage</a></h2>
227 <div class="doc-section">
229 <p>AdaptiveBlurImage() adaptively blurs the image by blurring less intensely near image edges and more intensely far from edges. We blur the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 and AdaptiveBlurImage() selects a suitable radius for you.</p>
231 <p>The format of the AdaptiveBlurImage method is:</p>
234 Image *AdaptiveBlurImage(const Image *image,const double radius,
235 const double sigma,ExceptionInfo *exception)
236 Image *AdaptiveBlurImageChannel(const Image *image,
237 const ChannelType channel,double radius,const double sigma,
238 ExceptionInfo *exception)
241 <p>A description of each parameter follows:</p>
247 <p>the channel type.</p>
250 <p>the radius of the Gaussian, in pixels, not counting the center pixel.</p>
253 <p>the standard deviation of the Laplacian, in pixels.</p>
256 <p>return any errors or warnings in this structure.</p>
259 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="AdaptiveSharpenImage">AdaptiveSharpenImage</a></h2>
260 <div class="doc-section">
262 <p>AdaptiveSharpenImage() adaptively sharpens the image by sharpening more intensely near image edges and less intensely far from edges. We sharpen the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 and AdaptiveSharpenImage() selects a suitable radius for you.</p>
264 <p>The format of the AdaptiveSharpenImage method is:</p>
267 Image *AdaptiveSharpenImage(const Image *image,const double radius,
268 const double sigma,ExceptionInfo *exception)
269 Image *AdaptiveSharpenImageChannel(const Image *image,
270 const ChannelType channel,double radius,const double sigma,
271 ExceptionInfo *exception)
274 <p>A description of each parameter follows:</p>
280 <p>the channel type.</p>
283 <p>the radius of the Gaussian, in pixels, not counting the center pixel.</p>
286 <p>the standard deviation of the Laplacian, in pixels.</p>
289 <p>return any errors or warnings in this structure.</p>
292 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="BlurImage">BlurImage</a></h2>
293 <div class="doc-section">
295 <p>BlurImage() blurs an image. We convolve the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, the radius should be larger than sigma. Use a radius of 0 and BlurImage() selects a suitable radius for you.</p>
297 <p>BlurImage() differs from GaussianBlurImage() in that it uses a separable kernel which is faster but mathematically equivalent to the non-separable kernel.</p>
299 <p>The format of the BlurImage method is:</p>
302 Image *BlurImage(const Image *image,const double radius,
303 const double sigma,ExceptionInfo *exception)
304 Image *BlurImageChannel(const Image *image,const ChannelType channel,
305 const double radius,const double sigma,ExceptionInfo *exception)
308 <p>A description of each parameter follows:</p>
314 <p>the channel type.</p>
317 <p>the radius of the Gaussian, in pixels, not counting the center pixel.</p>
320 <p>the standard deviation of the Gaussian, in pixels.</p>
323 <p>return any errors or warnings in this structure.</p>
326 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="ConvolveImage">ConvolveImage</a></h2>
327 <div class="doc-section">
329 <p>ConvolveImage() applies a custom convolution kernel to the image.</p>
331 <p>The format of the ConvolveImage method is:</p>
334 Image *ConvolveImage(const Image *image,const size_t order,
335 const double *kernel,ExceptionInfo *exception)
336 Image *ConvolveImageChannel(const Image *image,const ChannelType channel,
337 const size_t order,const double *kernel,ExceptionInfo *exception)
340 <p>A description of each parameter follows:</p>
346 <p>the channel type.</p>
349 <p>the number of columns and rows in the filter kernel.</p>
352 <p>An array of double representing the convolution kernel.</p>
355 <p>return any errors or warnings in this structure.</p>
358 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="DespeckleImage">DespeckleImage</a></h2>
359 <div class="doc-section">
361 <p>DespeckleImage() reduces the speckle noise in an image while perserving the edges of the original image. A speckle removing filter uses a complementary hulling technique (raising pixels that are darker than their surrounding neighbors, then complementarily lowering pixels that are brighter than their surrounding neighbors) to reduce the speckle index of that image (reference Crimmins speckle removal).</p>
363 <p>The format of the DespeckleImage method is:</p>
366 Image *DespeckleImage(const Image *image,ExceptionInfo *exception)
369 <p>A description of each parameter follows:</p>
375 <p>return any errors or warnings in this structure.</p>
378 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="EdgeImage">EdgeImage</a></h2>
379 <div class="doc-section">
381 <p>EdgeImage() finds edges in an image. Radius defines the radius of the convolution filter. Use a radius of 0 and EdgeImage() selects a suitable radius for you.</p>
383 <p>The format of the EdgeImage method is:</p>
386 Image *EdgeImage(const Image *image,const double radius,
387 ExceptionInfo *exception)
390 <p>A description of each parameter follows:</p>
396 <p>the radius of the pixel neighborhood.</p>
399 <p>return any errors or warnings in this structure.</p>
402 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="EmbossImage">EmbossImage</a></h2>
403 <div class="doc-section">
405 <p>EmbossImage() returns a grayscale image with a three-dimensional effect. We convolve the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 and Emboss() selects a suitable radius for you.</p>
407 <p>The format of the EmbossImage method is:</p>
410 Image *EmbossImage(const Image *image,const double radius,
411 const double sigma,ExceptionInfo *exception)
414 <p>A description of each parameter follows:</p>
420 <p>the radius of the pixel neighborhood.</p>
423 <p>the standard deviation of the Gaussian, in pixels.</p>
426 <p>return any errors or warnings in this structure.</p>
429 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="FilterImage">FilterImage</a></h2>
430 <div class="doc-section">
432 <p>FilterImage() applies a custom convolution kernel to the image.</p>
434 <p>The format of the FilterImage method is:</p>
437 Image *FilterImage(const Image *image,const KernelInfo *kernel,
438 ExceptionInfo *exception)
439 Image *FilterImageChannel(const Image *image,const ChannelType channel,
440 const KernelInfo *kernel,ExceptionInfo *exception)
443 <p>A description of each parameter follows:</p>
449 <p>the channel type.</p>
452 <p>the filtering kernel.</p>
455 <p>return any errors or warnings in this structure.</p>
458 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="GaussianBlurImage">GaussianBlurImage</a></h2>
459 <div class="doc-section">
461 <p>GaussianBlurImage() blurs an image. We convolve the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, the radius should be larger than sigma. Use a radius of 0 and GaussianBlurImage() selects a suitable radius for you</p>
463 <p>The format of the GaussianBlurImage method is:</p>
466 Image *GaussianBlurImage(const Image *image,onst double radius,
467 const double sigma,ExceptionInfo *exception)
468 Image *GaussianBlurImageChannel(const Image *image,
469 const ChannelType channel,const double radius,const double sigma,
470 ExceptionInfo *exception)
473 <p>A description of each parameter follows:</p>
479 <p>the channel type.</p>
482 <p>the radius of the Gaussian, in pixels, not counting the center pixel.</p>
485 <p>the standard deviation of the Gaussian, in pixels.</p>
488 <p>return any errors or warnings in this structure.</p>
491 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="MotionBlurImage">MotionBlurImage</a></h2>
492 <div class="doc-section">
494 <p>MotionBlurImage() simulates motion blur. We convolve the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 and MotionBlurImage() selects a suitable radius for you. Angle gives the angle of the blurring motion.</p>
496 <p>Andrew Protano contributed this effect.</p>
498 <p>The format of the MotionBlurImage method is:</p>
501 Image *MotionBlurImage(const Image *image,const double radius,
502 const double sigma,const double angle,ExceptionInfo *exception)
503 Image *MotionBlurImageChannel(const Image *image,const ChannelType channel,
504 const double radius,const double sigma,const double angle,
505 ExceptionInfo *exception)
508 <p>A description of each parameter follows:</p>
514 <p>the channel type.</p>
517 <p>the radius of the Gaussian, in pixels, not counting the center</p>
519 <p>the radius of the Gaussian, in pixels, not counting the center pixel.</p>
522 <p>the standard deviation of the Gaussian, in pixels.</p>
525 <p>Apply the effect along this angle.</p>
528 <p>return any errors or warnings in this structure.</p>
531 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="PreviewImage">PreviewImage</a></h2>
532 <div class="doc-section">
534 <p>PreviewImage() tiles 9 thumbnails of the specified image with an image processing operation applied with varying parameters. This may be helpful pin-pointing an appropriate parameter for a particular image processing operation.</p>
536 <p>The format of the PreviewImages method is:</p>
539 Image *PreviewImages(const Image *image,const PreviewType preview,
540 ExceptionInfo *exception)
543 <p>A description of each parameter follows:</p>
549 <p>the image processing operation.</p>
552 <p>return any errors or warnings in this structure.</p>
555 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="RadialBlurImage">RadialBlurImage</a></h2>
556 <div class="doc-section">
558 <p>RadialBlurImage() applies a radial blur to the image.</p>
560 <p>Andrew Protano contributed this effect.</p>
562 <p>The format of the RadialBlurImage method is:</p>
565 Image *RadialBlurImage(const Image *image,const double angle,
566 ExceptionInfo *exception)
567 Image *RadialBlurImageChannel(const Image *image,const ChannelType channel,
568 const double angle,ExceptionInfo *exception)
571 <p>A description of each parameter follows:</p>
577 <p>the channel type.</p>
580 <p>the angle of the radial blur.</p>
583 <p>return any errors or warnings in this structure.</p>
586 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="SelectiveBlurImage">SelectiveBlurImage</a></h2>
587 <div class="doc-section">
589 <p>SelectiveBlurImage() selectively blur pixels within a contrast threshold. It is similar to the unsharpen mask that sharpens everything with contrast above a certain threshold.</p>
591 <p>The format of the SelectiveBlurImage method is:</p>
594 Image *SelectiveBlurImage(const Image *image,const double radius,
595 const double sigma,const double threshold,ExceptionInfo *exception)
596 Image *SelectiveBlurImageChannel(const Image *image,
597 const ChannelType channel,const double radius,const double sigma,
598 const double threshold,ExceptionInfo *exception)
601 <p>A description of each parameter follows:</p>
607 <p>the channel type.</p>
610 <p>the radius of the Gaussian, in pixels, not counting the center pixel.</p>
613 <p>the standard deviation of the Gaussian, in pixels.</p>
616 <p>only pixels within this contrast threshold are included in the blur operation.</p>
619 <p>return any errors or warnings in this structure.</p>
622 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="ShadeImage">ShadeImage</a></h2>
623 <div class="doc-section">
625 <p>ShadeImage() shines a distant light on an image to create a three-dimensional effect. You control the positioning of the light with azimuth and elevation; azimuth is measured in degrees off the x axis and elevation is measured in pixels above the Z axis.</p>
627 <p>The format of the ShadeImage method is:</p>
630 Image *ShadeImage(const Image *image,const MagickBooleanType gray,
631 const double azimuth,const double elevation,ExceptionInfo *exception)
634 <p>A description of each parameter follows:</p>
640 <p>A value other than zero shades the intensity of each pixel.</p>
642 <h5>azimuth, elevation</h5>
643 <p>Define the light source direction.</p>
646 <p>return any errors or warnings in this structure.</p>
649 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="SharpenImage">SharpenImage</a></h2>
650 <div class="doc-section">
652 <p>SharpenImage() sharpens the image. We convolve the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 and SharpenImage() selects a suitable radius for you.</p>
654 <p>Using a separable kernel would be faster, but the negative weights cancel out on the corners of the kernel producing often undesirable ringing in the filtered result; this can be avoided by using a 2D gaussian shaped image sharpening kernel instead.</p>
656 <p>The format of the SharpenImage method is:</p>
659 Image *SharpenImage(const Image *image,const double radius,
660 const double sigma,ExceptionInfo *exception)
661 Image *SharpenImageChannel(const Image *image,const ChannelType channel,
662 const double radius,const double sigma,ExceptionInfo *exception)
665 <p>A description of each parameter follows:</p>
671 <p>the channel type.</p>
674 <p>the radius of the Gaussian, in pixels, not counting the center pixel.</p>
677 <p>the standard deviation of the Laplacian, in pixels.</p>
680 <p>return any errors or warnings in this structure.</p>
683 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="SpreadImage">SpreadImage</a></h2>
684 <div class="doc-section">
686 <p>SpreadImage() is a special effects method that randomly displaces each pixel in a block defined by the radius parameter.</p>
688 <p>The format of the SpreadImage method is:</p>
691 Image *SpreadImage(const Image *image,const double radius,
692 ExceptionInfo *exception)
695 <p>A description of each parameter follows:</p>
701 <p>Choose a random pixel in a neighborhood of this extent.</p>
704 <p>return any errors or warnings in this structure.</p>
707 <h2><a href="http://www.imagemagick.org/api/MagickCore/effect_8c.html" id="UnsharpMaskImage">UnsharpMaskImage</a></h2>
708 <div class="doc-section">
710 <p>UnsharpMaskImage() sharpens one or more image channels. We convolve the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 and UnsharpMaskImage() selects a suitable radius for you.</p>
712 <p>The format of the UnsharpMaskImage method is:</p>
715 Image *UnsharpMaskImage(const Image *image,const double radius,
716 const double sigma,const double amount,const double threshold,
717 ExceptionInfo *exception)
718 Image *UnsharpMaskImageChannel(const Image *image,
719 const ChannelType channel,const double radius,const double sigma,
720 const double amount,const double threshold,ExceptionInfo *exception)
723 <p>A description of each parameter follows:</p>
729 <p>the channel type.</p>
732 <p>the radius of the Gaussian, in pixels, not counting the center pixel.</p>
735 <p>the standard deviation of the Gaussian, in pixels.</p>
738 <p>the percentage of the difference between the original and the blur image that is added back into the original.</p>
741 <p>the threshold in pixels needed to apply the diffence amount.</p>
744 <p>return any errors or warnings in this structure.</p>
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