Create a circle.
The operator gen_circle generates one or more circles described by the center and Radius. If several circles shall be generated the coordinates must be passed in the form of tuples.
The coordinate system runs from (0,0) (upper left corner) to (Width-1,Height-1). See get_system and reset_obj_db in this context.
If an integer value (1,2,3..) is given for the radius the result is an even-numbered diameter and thus an asymmetrical circle. In case of an odd-numbered diameter (radius = 1.5,2.5,3.5...) a symmetrical circle is obtained.
If the circle extends beyond the image edge it is clipped to the current image format according to the value of the system flag 'clip_region' (set_system).
|
Circle (output_object) |
region(-array) -> object |
| Generated circle. | |
|
Row (input_control) |
circle.center.y(-array) -> real / integer |
| Line index of center. | |
| Default value: 200.0 | |
| Suggested values: 0.0, 10.0, 50.0, 100.0, 200.0, 300.0 | |
| Typical range of values: 1.0 <= Row <= 1024.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
|
Column (input_control) |
circle.center.x(-array) -> real / integer |
| Column index of center. | |
| Default value: 200.0 | |
| Suggested values: 0.0, 10.0, 50.0, 100.0, 200.0, 300.0 | |
| Typical range of values: 1.0 <= Column <= 1024.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
|
Radius (input_control) |
circle.radius(-array) -> real / integer |
| Radius of circle. | |
| Default value: 100.5 | |
| Suggested values: 1.0, 1.5, 2.0, 2.5, 3, 3.5, 4, 4.5, 5.5, 6.5, 7.5, 9.5, 11.5, 15.5, 20.5, 25.5, 31.5, 50.5 | |
| Typical range of values: 1.0 <= Radius <= 1024.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
| Restriction: Radius > 0.0 | |
open_window(0,0,-1,-1,'root','visible','',WindowHandle) read_image(Image,'meer') gen_circle(Circle,300.0,200.0,150.5) reduce_domain(Image,Circle,Mask) disp_color(Mask,WindowHandle).
Runtime complexity: O(Radius * 2)
Storage complexity (byte): O(Radius * 8)
If the parameter values are correct, the operator gen_circle returns the value 2 (H_MSG_TRUE). Otherwise an exception handling is raised. The clipping according to the current image format is set via the operator set_system('clip_region',<'true'/'false'>). If an empty region is created by clipping (the circle is completely outside of the image format) the operator set_system('store_empty_region',<true/false>) determines whether the empty region is put out.
gen_circle is reentrant and processed without parallelization.
gen_ellipse, gen_region_polygon_filled, gen_region_points, gen_region_runs, draw_circle
disp_circle, set_shape, smallest_circle, reduce_domain
Region processing
