info_edgesT_info_edgesInfoEdgesInfoEdgesinfo_edges (Operator)

Name

info_edgesT_info_edgesInfoEdgesInfoEdgesinfo_edges — Return the filter coefficients of a filter in edges_imageedges_imageEdgesImageEdgesImageEdgesImageedges_image.

Signature

Description

info_edgesinfo_edgesInfoEdgesInfoEdgesInfoEdgesinfo_edges returns the coefficients CoeffsCoeffsCoeffsCoeffscoeffscoeffs and an estimate of the width SizeSizeSizeSizesizesize of any of the filters used in edges_imageedges_imageEdgesImageEdgesImageEdgesImageedges_image. To do so, the corresponding continuous impulse responses of the filters are sampled until the first filter coefficient is smaller than five percent of the largest coefficient. AlphaAlphaAlphaAlphaalphaalpha is the filter parameter (see edges_imageedges_imageEdgesImageEdgesImageEdgesImageedges_image). Seven edge operators are supported (parameter FilterFilterFilterFilterfilterfilter):

'deriche1', 'lanser1', 'deriche2', 'lanser2', 'shen', 'mshen' and 'canny'.

The parameter ModeModeModeModemodemode ('edge'/'smooth') is used to determine whether the corresponding edge or smoothing operator is to be sampled.

The Canny operator (which uses Gaussian smoothing) is implemented using conventional filter masks. Therefore, for the Canny filter, the coefficients CoeffsCoeffsCoeffsCoeffscoeffscoeffs of the one-dimensional impulse responses are returned as . All other filters are implemented recursively; here, the CoeffsCoeffsCoeffsCoeffscoeffscoeffs are coefficients of a corresponding non-recursive filter.

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

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Processed without parallelization.

Parameters

read_image(Image,'fabrik')
info_edges('lanser2','edge',0.5,Size,Coeffs)
edges_image(Image,Amp,Dir,'lanser2',0.5,'none',-1,-1)
hysteresis_threshold(Amp,Margin,20,30,30)

read_image(&Image,"fabrik");
info_edges("lanser2","edge",0.5,Size,Coeffs);
edges_image(Image,&Amp,&Dir,"lanser2",0.5,"none",-1,-1);
hysteresis_threshold(Amp,&Margin,20,30,30);

read_image(Image,'fabrik')
info_edges('lanser2','edge',0.5,Size,Coeffs)
edges_image(Image,Amp,Dir,'lanser2',0.5,'none',-1,-1)
hysteresis_threshold(Amp,Margin,20,30,30)

read_image(Image,'fabrik')
info_edges('lanser2','edge',0.5,Size,Coeffs)
edges_image(Image,Amp,Dir,'lanser2',0.5,'none',-1,-1)
hysteresis_threshold(Amp,Margin,20,30,30)

read_image(Image,'fabrik')
info_edges('lanser2','edge',0.5,Size,Coeffs)
edges_image(Image,Amp,Dir,'lanser2',0.5,'none',-1,-1)
hysteresis_threshold(Amp,Margin,20,30,30)

Result

info_edgesinfo_edgesInfoEdgesInfoEdgesInfoEdgesinfo_edges returns 2 (H_MSG_TRUE) if all parameters are correct. 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>)set_system("no_object_result",<Result>). If necessary, an exception is raised.

Possible Successors

edges_imageedges_imageEdgesImageEdgesImageEdgesImageedges_image, thresholdthresholdThresholdThresholdThresholdthreshold, skeletonskeletonSkeletonSkeletonSkeletonskeleton

See also

edges_imageedges_imageEdgesImageEdgesImageEdgesImageedges_image

Module

Foundation