kirsch_amp (Operator)

Name

kirsch_amp — Detect edges (amplitude) using the Kirsch operator.

Synopsis

kirsch_amp(Image : ImageEdgeAmp : : )

Description

kirsch_amp 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:

     -3  -3   5       -3   5   5      5   5   5       5   5  -3
     -3   0   5       -3   0   5     -3   0  -3       5   0  -3
     -3  -3   5       -3  -3  -3     -3  -3  -3      -3  -3  -3

      5  -3  -3       -3  -3  -3     -3  -3  -3      -3  -3  -3
      5   0  -3        5   0  -3     -3   0  -3      -3   0   5
      5  -3  -3        5   5  -3      5   5   5      -3   5   5

The result image contains the maximum response of all masks.

Parameters

Image (input_object)	(multichannel-)image(-array) → object (byte / int2 / uint2)
Input image.

ImageEdgeAmp (output_object)	image(-array) → object (byte / int2 / uint2)
Edge amplitude (gradient magnitude) image.

Example

read_image(Image,'fabrik')
kirsch_amp(Image,Kirsch_amp)
threshold(Kirsch_amp,Edges,128,255)

Result

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

Parallelization Information

kirsch_amp is reentrant and automatically parallelized (on tuple level, channel level, domain level).

Possible Predecessors

binomial_filter, gauss_image, sigma_image, median_image, smooth_image

Alternatives

sobel_amp, frei_amp, prewitt_amp, robinson_amp, roberts

See also

bandpass_image, laplace_of_gauss

Module

Foundation