robinson_ampRobinsonAmpRobinsonAmprobinson_amprobinson_amp🔗

Short description🔗

robinson_ampRobinsonAmpRobinsonAmprobinson_amprobinson_amp — Detect edges (amplitude) using the Robinson operator.

Signature🔗

robinson_amp( image Image, out image ImageEdgeAmp )

HImage HImage::RobinsonAmp( ) const

HImage HImage.RobinsonAmp( )

Description🔗

robinson_ampRobinsonAmp calculates an approximation of the first derivative of the image data and is used as an edge detector. In robinson_ampRobinsonAmp the following four of the originally proposed eight 3x3 filter masks are convolved with the image. The other four masks are obtained by a multiplication by -1. All masks contain only the values 0,1,-1,2,-2.

       -1   0   1                2   1   0
       -2   0   2                1   0  -1
       -1   0   1                0  -1  -2

        0   1   2                1   2   1
       -1   0   1                0   0   0
       -2  -1   0               -1  -2  -1

The result image contains the maximum response of all masks.

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🔗

Execution information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Automatically parallelized on tuple level.
Automatically parallelized on channel level.
Automatically parallelized on domain level.

Parameters🔗

Imageimageimage (input_object) (multichannel-)image(-array) → object (byte / int2 / uint2)HObject (byte / int2 / uint2)HImage (byte / int2 / uint2)HObject (byte / int2 / uint2)Hobject (byte / int2 / uint2)

Input image.

ImageEdgeAmpimageEdgeAmpimage_edge_amp (output_object) (multichannel-)image(-array) → object (byte / int2 / uint2)HObject (byte / int2 / uint2)HImage (byte / int2 / uint2)HObject (byte / int2 / uint2)Hobject * (byte / int2 / uint2)

Edge amplitude (gradient magnitude) image.

Example🔗

(HDevelop)

read_image(Image,'fabrik')
robinson_amp(Image,Robinson_amp)
threshold(Robinson_amp,Edges,128,255)

(C)

read_image(&Image,"fabrik")\;
robinson_amp(Image,&Robinson_amp)\;
threshold(Robinson_amp,&Edges,128,255)\;

Result🔗

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

Combinations with other operators🔗

Combinations

Possible predecessors

binomial_filterBinomialFilter, gauss_filterGaussFilter, sigma_imageSigmaImage, median_imageMedianImage, smooth_imageSmoothImage

Alternatives

sobel_ampSobelAmp, frei_ampFreiAmp, prewitt_ampPrewittAmp, robertsRoberts

Module🔗

Foundation