| Laplacian Effect | ||
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The Laplacian filter is used for detection of edges in an image. It highlights areas in which intensity changes rapidly producing a picture of all the edges in an image.
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Settings
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Workings
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The Laplacian filter is a standard Laplacian of Gaussian convolution. This is a second derivative function designed to measure changes in intensity without being overly sensitive to noise. The function produces a peak at the start of the change in intensity and then at the end of the change. Because the Laplacian of Gaussian produces a fairly wide convolution for a small radius this filter can become quite computationally expensive as radius is increased.
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Example
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The following examples show the effect of a Laplacian filter applied with a number of different settings.
void function() {
using (Doc doc = new Doc()) {
AddImagePage(doc, img3); // original image
doc.Rendering.Save("EffectLaplacian.jpg");
using (ImageLayer layer = AddImagePage(doc, img3)) {
using (EffectOperation effect = new EffectOperation("Laplacian")) {
effect.Parameters["Radius"].Value = 0.8;
effect.Apply(layer.PixMap);
}
}
doc.Rendering.Save("EffectLaplacian08.jpg");
using (ImageLayer layer = AddImagePage(doc, img3)) {
using (EffectOperation effect = new EffectOperation("Laplacian")) {
effect.Parameters["Radius"].Value = 1.6;
effect.Apply(layer.PixMap);
}
}
doc.Rendering.Save("EffectLaplacian16.jpg");
using (ImageLayer layer = AddImagePage(doc, img3)) {
using (EffectOperation effect = new EffectOperation("Laplacian")) {
effect.Parameters["Radius"].Value = 3.2;
effect.Apply(layer.PixMap);
}
}
doc.Rendering.Save("EffectLaplacian32.jpg");
}
}
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