bandpass_imagebandpass_imageBandpassImageBandpassImage (Operator)

Name

bandpass_imagebandpass_imageBandpassImageBandpassImage — Edge extraction using bandpass filters.

Signature

bandpass_image(Image : ImageBandpass : FilterType : )

Description

bandpass_imagebandpass_imageBandpassImageBandpassImageBandpassImage 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_ampSobelAmpSobelAmpSobelAmp 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.

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).
Automatically parallelized on tuple level.
Automatically parallelized on channel level.
Automatically parallelized on domain level.

Parameters

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

Input images.

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

Bandpass-filtered images.

FilterTypeFilterTypeFilterTypeFilterTypefilterType (input_control) string → (string)

Filter type: currently only 'lines' is supported.

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

List of values: '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_imageBandpassImageBandpassImageBandpassImage 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>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>). If necessary, an exception is raised.

Possible Successors

thresholdthresholdThresholdThresholdThreshold, skeletonskeletonSkeletonSkeletonSkeleton

Alternatives

convol_imageconvol_imageConvolImageConvolImageConvolImage, topographic_sketchtopographic_sketchTopographicSketchTopographicSketchTopographicSketch, texture_lawstexture_lawsTextureLawsTextureLawsTextureLaws

Module

Foundation

Operators