prewitt_ampprewitt_ampPrewittAmpPrewittAmp (Operator)

Name

prewitt_ampprewitt_ampPrewittAmpPrewittAmp — Detect edges (amplitude) using the Prewitt operator.

Signature

prewitt_amp(Image : ImageEdgeAmp : : )

Herror prewitt_amp(const Hobject Image, Hobject* ImageEdgeAmp)

Herror T_prewitt_amp(const Hobject Image, Hobject* ImageEdgeAmp)

void PrewittAmp(const HObject& Image, HObject* ImageEdgeAmp)

HImage HImage::PrewittAmp() const

static void HOperatorSet.PrewittAmp(HObject image, out HObject imageEdgeAmp)

HImage HImage.PrewittAmp()

Description

prewitt_ampprewitt_ampPrewittAmpPrewittAmpPrewittAmp calculates an approximation of the first derivative of the image data and is used as an edge detector. The filter is based on the following filter masks: A = 1 1 1 0 0 0 -1 -1 -1 B = 1 0 -1 1 0 -1 1 0 -1 The result image contains the maximum response of the masks A and B.

Attention

Note that filter operators may return unexpected results if an image with a reduced domain is used as input. Please refer to the chapter Filters.

Execution Information

Parameters

ImageImageImageImageimage (input_object)  (multichannel-)image(-array) objectHImageHImageHobject (byte / int2 / uint2)

Input image.

ImageEdgeAmpImageEdgeAmpImageEdgeAmpImageEdgeAmpimageEdgeAmp (output_object)  (multichannel-)image(-array) objectHImageHImageHobject * (byte / int2 / uint2)

Edge amplitude (gradient magnitude) image.

Example (HDevelop)

read_image(Image,'fabrik')
prewitt_amp(Image,Prewitt)
threshold(Prewitt,Edges,128,255)

Example (C)

read_image(&Image,"fabrik");
prewitt_amp(Image,&Prewitt);
threshold(Prewitt,&Edges,128,255);

Example (HDevelop)

read_image(Image,'fabrik')
prewitt_amp(Image,Prewitt)
threshold(Prewitt,Edges,128,255)

Example (HDevelop)

read_image(Image,'fabrik')
prewitt_amp(Image,Prewitt)
threshold(Prewitt,Edges,128,255)

Example (HDevelop)

read_image(Image,'fabrik')
prewitt_amp(Image,Prewitt)
threshold(Prewitt,Edges,128,255)

Result

prewitt_ampprewitt_ampPrewittAmpPrewittAmpPrewittAmp always returns 2 (H_MSG_TRUE). If the input is empty the behavior can be set via set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>). If necessary, an exception is raised.

Possible Predecessors

binomial_filterbinomial_filterBinomialFilterBinomialFilterBinomialFilter, gauss_filtergauss_filterGaussFilterGaussFilterGaussFilter, sigma_imagesigma_imageSigmaImageSigmaImageSigmaImage, median_imagemedian_imageMedianImageMedianImageMedianImage, smooth_imagesmooth_imageSmoothImageSmoothImageSmoothImage

Possible Successors

thresholdthresholdThresholdThresholdThreshold, gray_skeletongray_skeletonGraySkeletonGraySkeletonGraySkeleton, nonmax_suppression_ampnonmax_suppression_ampNonmaxSuppressionAmpNonmaxSuppressionAmpNonmaxSuppressionAmp, close_edgesclose_edgesCloseEdgesCloseEdgesCloseEdges, close_edges_lengthclose_edges_lengthCloseEdgesLengthCloseEdgesLengthCloseEdgesLength

Alternatives

sobel_ampsobel_ampSobelAmpSobelAmpSobelAmp, kirsch_ampkirsch_ampKirschAmpKirschAmpKirschAmp, frei_ampfrei_ampFreiAmpFreiAmpFreiAmp, robinson_amprobinson_ampRobinsonAmpRobinsonAmpRobinsonAmp, robertsrobertsRobertsRobertsRoberts

See also

bandpass_imagebandpass_imageBandpassImageBandpassImageBandpassImage, laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGaussLaplaceOfGauss

Module

Foundation