bandpass_imagebandpass_imageBandpassImagebandpass_imageBandpassImageBandpassImage (Operator)

Name

bandpass_imagebandpass_imageBandpassImagebandpass_imageBandpassImageBandpassImage — Edge extraction using bandpass filters.

Signature

bandpass_image(Image : ImageBandpass : FilterType : )

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

FilterTypeFilterTypeFilterTypeFilterTypeFilterTypefilterType: 'lines' In contrast to the edge operator sobel_ampsobel_ampSobelAmpsobel_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 ImageBandpassImageBandpassImageBandpassImageBandpassImageBandpassimageBandpass.

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

ImageImageImageImageImageimage (input_object) (multichannel-)image(-array) → object (byte / uint2)

Input images.

ImageBandpassImageBandpassImageBandpassImageBandpassImageBandpassimageBandpass (output_object) (multichannel-)image(-array) → object (byte / uint2)

Bandpass-filtered images.

FilterTypeFilterTypeFilterTypeFilterTypeFilterTypefilterType (input_control) string → (string)

Filter type: currently only 'lines' is supported.

Default value: 'lines' "lines" "lines" "lines" "lines" "lines"

List of values: 'lines'"lines""lines""lines""lines""lines"

Example (C)

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

Result

bandpass_imagebandpass_imageBandpassImagebandpass_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>)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.

Possible Successors

thresholdthresholdThresholdthresholdThresholdThreshold, skeletonskeletonSkeletonskeletonSkeletonSkeleton

Alternatives

convol_imageconvol_imageConvolImageconvol_imageConvolImageConvolImage, topographic_sketchtopographic_sketchTopographicSketchtopographic_sketchTopographicSketchTopographicSketch, texture_lawstexture_lawsTextureLawstexture_lawsTextureLawsTextureLaws

Module

Foundation

Operators