bandpass_image (Operator)

Name

bandpass_image — Edge extraction using bandpass filters.

Synopsis

bandpass_image(Image : ImageBandpass : FilterType : )

Description

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

FilterType: 'lines' In contrast to the edge operator sobel_amp 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 ImageBandpass.

Parameters

Image (input_object)	(multichannel-)image(-array) → object (byte / uint2)
Input images.

ImageBandpass (output_object)	(multichannel-)image(-array) → object (byte / uint2)
Bandpass-filtered images.

FilterType (input_control)	string → (string)
Filter type: currently only 'lines' is supported.
Default value: 'lines'
List of values: 'lines'

Example (Syntax: C)

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

Result

bandpass_image 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>:). If necessary, an exception is raised.

Parallelization Information

bandpass_image is reentrant and automatically parallelized (on tuple level, channel level, domain level).

Possible Successors

threshold, skeleton

Alternatives

convol_image, topographic_sketch, texture_laws

See also

highpass_image, gray_skeleton

Module

Foundation