Operator Reference
bandpass_image (Operator)
bandpass_image
— Edge extraction using bandpass filters.
Signature
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
.
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
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: 'lines'
List of values: 'lines'
Example (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 behavior can be set via
set_system(::'no_object_result',<Result>:)
. If
necessary, an exception is raised.
Possible Successors
Alternatives
convol_image
,
topographic_sketch
,
texture_laws
See also
Module
Foundation