Polygon approximation of a region.
The operator ::get_region_polygon calculates a polygon to approximate the edge of a region. A polygon is a sequence of line (Rows) and column coordinates (Columns). It describes the contour of the region. Only the base points of the polygon are returned. The parameter Tolerance indicates how large the maximum distance between the polygon and the edge of the region may be. Holes of the region are ignored. The operator ::get_region_polygon returns the coordinates in the form of tuples.
Holes of the region are ignored. Only one region may be passed, and this region must have exactly one connection component.
|
Region (input_object) |
region -> Hobject: HRegion |
| Region to be approximated. | |
|
Tolerance (input_control) |
number -> HTuple.double / long |
| Maximum distance between the polygon and the edge of the region. | |
| Default value: 5.0 | |
| Suggested values: 0.0, 2.0, 5.0, 10.0 | |
| Typical range of values: 0.0 <= Tolerance | |
| Minimum increment: 0.01 | |
|
Recommended increment: 1.0 | |
|
Rows (output_control) |
polygon.y-array -> HTuple.long * |
| Line numbers of the base points of the contour. | |
|
Columns (output_control) |
polygon.x-array -> HTuple.long * |
| Column numbers of the base points of the contour. | |
| Number of elements: Columns == Rows | |
The operator ::get_region_polygon normally returns the value H_MSG_TRUE. If more than one connection component is passed an exception handling is caused. The behavior in case of empty input (no input regions available) is set via the operator ::set_system('no_object_result',<Result>).
::sobel_amp, ::threshold, ::skeleton, ::edges_image
::copy_obj, ::gen_region_polygon, ::disp_polygon, ::get_region_chain, ::get_region_contour, ::set_line_approx
Region processing
