bandpass_imagebandpass_imagebandpass_imageBandpassImageBandpassImage (Operator)

Name

bandpass_imagebandpass_imagebandpass_imageBandpassImageBandpassImage — Edge extraction using bandpass filters.

Signature

Description

bandpass_imagebandpass_imagebandpass_imageBandpassImageBandpassImage serves as an edge filter. It applies a linear filter with the following convolution mask to ImageImageImageImageimage:

FilterTypeFilterTypeFilterTypeFilterTypefilterType: 'lines' In contrast to the edge operator sobel_ampsobel_ampsobel_ampSobelAmpSobelAmp this filter detects lines instead of edges, i.e., two closely adjacent edges.

             0      -2      -2      -2       0
            -2       0       3       0      -2
            -2       3      12       3      -2
            -2       0       3       0      -2
             0      -2      -2      -2       0

At the border of the image the gray values are mirrored. Over- and underflows of gray values are clipped. The resulting images are returned in ImageBandpassImageBandpassImageBandpassImageBandpassimageBandpass.

Parallelization

• 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

Example (C)

bandpass_image(Image,&LineImage,"lines");
threshold(LineImage,&Lines,60.0,255.0);
skeleton(Lines,&ThinLines);

Result

bandpass_imagebandpass_imagebandpass_imageBandpassImageBandpassImage returns 2 (H_MSG_TRUE) if all parameters are correct. If the input is empty the behaviour can be set via set_system(::'no_object_result',<Result>:)set_system("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.

Possible Successors

thresholdthresholdthresholdThresholdThreshold, skeletonskeletonskeletonSkeletonSkeleton

Alternatives

convol_imageconvol_imageconvol_imageConvolImageConvolImage, topographic_sketchtopographic_sketchtopographic_sketchTopographicSketchTopographicSketch, texture_lawstexture_lawstexture_lawsTextureLawsTextureLaws

See also

highpass_imagehighpass_imagehighpass_imageHighpassImageHighpassImage, gray_skeletongray_skeletongray_skeletonGraySkeletonGraySkeleton

Module

Foundation