gen_random_regions — Create random regions like circles, rectangles and ellipses.
gen_random_regions( : Regions : Type, WidthMin, WidthMax, HeightMin, HeightMax, PhiMin, PhiMax, NumRegions, Width, Height : )
The operator gen_random_regions generates regions,
whose parameters are determined at random within the given limits,
and returns them in Regions.
The parameter NumRegions determines how many regions are created.
The position is always random and cannot be determined by parameters,
but the center of every region lies in the pixel area
[0...Width-1]
[0...Height-1].
The parameter Type defines the type of the regions.
The meaning of the lower and upper limits depends on Type:
'rectangle1': Minimum/maximum width/height.
'rectangle2': Minimum/maximum half edge lengths,
minimum/maximum rotation angle.
Thereby the larger value is used for the first half edge length.
The parameters correspond to the parameters Length1,
Length2, and Phi of gen_rectangle2.
'circle': WidthMin and WidthMax determine
the minimum and maximum radii.
The parameters correspond to the parameter Radius in
gen_circle.
HeightMin and HeightMax as well as
PhiMin and PhiMax are without further significance.
'ellipse': Minimum/maximum half-radii and minimal/maximum
rotation angle.
Thereby the larger value is used for the first half-radius.
The parameters correspond to the parameters Radius1,
Radius2, and Phi in gen_ellipse.
'ring': Minimum/maximum radii, whereby the larger one determines the radius of the larger circle and the smaller one the radius of the hole.
The random parameters are generated using the C function “nrand48()”.
See the parameter 'seed_rand' of set_system for
information on the used random seed.
Regions (output_object) region-array → object
Created regions.
Type (input_control) string → (string)
Type of regions to be created.
Default: 'circle'
List of values: 'circle', 'ellipse', 'rectangle1', 'rectangle2', 'ring'
WidthMin (input_control) number → (real / integer)
Minimum object characteristic, depending on type and value.
Default: 10.0
Suggested values: 1.0, 3.0, 5.0, 10.0, 20.0, 40.0, 80.0
Value range:
0
≤
WidthMin
(lin)
Minimum increment: 1.0
Recommended increment: 10.0
WidthMax (input_control) number → (real / integer)
Maximum object characteristic, depending on type and value.
Default: 20.0
Suggested values: 1.0, 3.0, 5.0, 10.0, 20.0, 40.0, 80.0
Value range:
WidthMax
(lin)
Minimum increment: 1.0
Recommended increment: 10.0
Restriction:
WidthMin <= WidthMax
HeightMin (input_control) number → (real / integer)
Minimum object characteristic, depending on type and value.
Default: 10.0
Suggested values: 1.0, 3.0, 5.0, 10.0, 20.0, 40.0, 80.0
Value range:
0
≤
HeightMin
(lin)
Minimum increment: 1.0
Recommended increment: 10.0
HeightMax (input_control) number → (real / integer)
Maximum object characteristic, depending on type and value.
Default: 30.0
Suggested values: 1.0, 3.0, 5.0, 10.0, 20.0, 40.0, 80.0
Value range:
HeightMax
(lin)
Minimum increment: 1.0
Recommended increment: 10.0
Restriction:
HeightMin <= HeightMax
PhiMin (input_control) number → (real / integer)
Minimum rotation angle of the region.
Default: -0.7854
Suggested values: 0.0, 0.1, 0.3, 0.6, 0.9, 1.2, 1.5
Value range:
0.0
≤
PhiMin
≤
6.28 (lin)
Restriction:
PhiMin > 0
PhiMax (input_control) number → (real / integer)
Maximum rotation angle of the region.
Default: 0.7854
Suggested values: 0.0, 0.1, 0.3, 0.6, 0.9, 1.2, 1.5
Value range:
0.0
≤
PhiMax
≤
6.28 (lin)
Restriction:
PhiMax > 0
NumRegions (input_control) integer → (integer)
Number of regions.
Default: 100
Suggested values: 1, 5, 20, 100, 200, 500, 1000, 2000
Value range:
1
≤
NumRegions
(lin)
Minimum increment: 1
Recommended increment: 10
Width (input_control) integer → (integer)
Maximum horizontal expansion of the centers.
Default: 512
Suggested values: 128, 256, 512, 1024
Value range:
1
≤
Width
(lin)
Minimum increment: 1
Recommended increment: 10
Height (input_control) integer → (integer)
Maximum vertical expansion of the centers.
Default: 512
Suggested values: 128, 256, 512, 1024
Value range:
1
≤
Height
(lin)
Minimum increment: 1
Recommended increment: 10
If the parameter values are correct gen_random_regions returns
the value 2 (
H_MSG_TRUE)
.
Otherwise an exception is raised.
The clipping according to the current image format is determined by
the operator set_system('clip_region',<'true'/'false'>).
Foundation