Name
prewitt_dir prewitt_dir PrewittDir prewitt_dir PrewittDir PrewittDir — Detect edges (amplitude and direction) using the Prewitt operator.
prewitt_dir prewitt_dir PrewittDir prewitt_dir PrewittDir PrewittDir 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. The edge directions are returned in ImageEdgeDir ImageEdgeDir ImageEdgeDir ImageEdgeDir ImageEdgeDir imageEdgeDir ,
and are stored in 2-degree steps, i.e., an edge direction of
x degrees mathematically positive sense and
with respect to the horizontal axis is stored as
x / 2 in the edge direction image. Furthermore, the
direction of the change of intensity is taken into account. Let
denote the image gradient. Then the
following edge directions are returned as r/2:
Points with edge amplitude 0 are assigned the edge direction 255
(undefined direction).
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 .
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.
Edge amplitude (gradient magnitude) image.
read_image(Image,'fabrik')
prewitt_dir(Image,PrewittA,PrewittD)
threshold(PrewittA,Edges,128,255)
read_image(&Image,"fabrik");
prewitt_dir(Image,&PrewittA,&PrewittD);
threshold(PrewittA,&Edges,128,255);
read_image(Image,'fabrik')
prewitt_dir(Image,PrewittA,PrewittD)
threshold(PrewittA,Edges,128,255)
read_image(Image,'fabrik')
prewitt_dir(Image,PrewittA,PrewittD)
threshold(PrewittA,Edges,128,255)
read_image(Image,'fabrik')
prewitt_dir(Image,PrewittA,PrewittD)
threshold(PrewittA,Edges,128,255)
read_image(Image,'fabrik')
prewitt_dir(Image,PrewittA,PrewittD)
threshold(PrewittA,Edges,128,255)
prewitt_dir prewitt_dir PrewittDir prewitt_dir PrewittDir PrewittDir 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>) set_system("no_object_result",<Result>) SetSystem("no_object_result",<Result>) SetSystem("no_object_result",<Result>) .
If necessary, an exception is raised.
binomial_filter binomial_filter BinomialFilter binomial_filter BinomialFilter BinomialFilter ,
gauss_filter gauss_filter GaussFilter gauss_filter GaussFilter GaussFilter ,
sigma_image sigma_image SigmaImage sigma_image SigmaImage SigmaImage ,
median_image median_image MedianImage median_image MedianImage MedianImage ,
smooth_image smooth_image SmoothImage smooth_image SmoothImage SmoothImage
hysteresis_threshold hysteresis_threshold HysteresisThreshold hysteresis_threshold HysteresisThreshold HysteresisThreshold ,
threshold threshold Threshold threshold Threshold Threshold ,
gray_skeleton gray_skeleton GraySkeleton gray_skeleton GraySkeleton GraySkeleton ,
nonmax_suppression_dir nonmax_suppression_dir NonmaxSuppressionDir nonmax_suppression_dir NonmaxSuppressionDir NonmaxSuppressionDir ,
close_edges close_edges CloseEdges close_edges CloseEdges CloseEdges ,
close_edges_length close_edges_length CloseEdgesLength close_edges_length CloseEdgesLength CloseEdgesLength
edges_image edges_image EdgesImage edges_image EdgesImage EdgesImage ,
sobel_dir sobel_dir SobelDir sobel_dir SobelDir SobelDir ,
robinson_dir robinson_dir RobinsonDir robinson_dir RobinsonDir RobinsonDir ,
frei_dir frei_dir FreiDir frei_dir FreiDir FreiDir ,
kirsch_dir kirsch_dir KirschDir kirsch_dir KirschDir KirschDir
bandpass_image bandpass_image BandpassImage bandpass_image BandpassImage BandpassImage ,
laplace_of_gauss laplace_of_gauss LaplaceOfGauss laplace_of_gauss LaplaceOfGauss LaplaceOfGauss
Foundation