gen_random_region — Create a random region.
gen_random_region( : RegionRandom : Width, Height : )
The operator gen_random_region returns a random region.
During this process every pixel in the image area
[0...Width-1]
[0...Height-1] is adapted into the region with
the probability 0.5.
The created region can be imagined as the
threshold formation in an image with noise.
This procedure is particularly important for the creation of uncorrelated binary patterns.
The random pattern is generated using the C function “nrand48()”.
See the parameter 'seed_rand' of set_system for
information on the used random seed.
If Width and Height are chosen large
(> 100) the created region may require much storage space due to
the internally used runlength coding.
The gray values of the output region are undefined.
Width (input_control) extent.x → (integer)
Maximum horizontal expansion of random region.
Default: 128
Suggested values: 16, 32, 50, 64, 100, 128, 256, 300, 400, 512
Value range:
Width
(lin)
Minimum increment: 1
Recommended increment: 10
Restriction:
Width > 0
Height (input_control) extent.y → (integer)
Maximum vertical expansion of random region.
Default: 128
Suggested values: 16, 32, 50, 64, 100, 128, 256, 300, 400, 512
Value range:
Height
(lin)
Minimum increment: 1
Recommended increment: 10
Restriction:
Height > 0
The worst case for the storage complexity for the created region (in byte) is: O(Width * Height * 2).
If the parameter values are correct, the operator gen_random_region
returns the value 2 (
H_MSG_TRUE)
.
Otherwise an exception is raised.
The clipping according to the current image format is set via the
operator set_system('clip_region',<'true'/'false'>).
gen_checker_region,
add_noise_distribution,
add_noise_white,
reduce_domain
Foundation