Edge extraction using bandpass filters.
bandpass__ 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 to the interval [0,255]. The resulting images are returned in ImageBandpass.
Image (input_object) |
image(-array) -> object : byte |
Input images. |
ImageBandpass (output_object) |
image(-array) -> object : byte |
Bandpass-filtered images. |
FilterType (input_control) |
string -> string |
Filter type: currently only 'lines' is supported. | |
Default value: 'lines' | |
List of values: 'lines' |
bandpass__(Image,&LineImage,"lines"); threshold__(LineImage,&Lines,60.0,255.0); skeleton(Lines,&ThinLines);
bandpass__ returns 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.
convol__, topographic_sketch, laws_byte