Operator Reference
noise_distribution_mean (Operator)
noise_distribution_mean
— Determine the noise distribution of an image.
Signature
noise_distribution_mean(ConstRegion, Image : : FilterSize : Distribution)
Description
noise_distribution_mean
calculates the noise
distribution in a region of the image Image
. The
parameter ConstRegion
determines a region of the image
with approximately constant gray values. Ideally, the changes in
gray values should only be caused by noise in this region. From
this region the noise distribution is determined by using the
mean_image
operator to smooth the image, and to use the gray
value differences in this area as an estimate for the noise
distribution, which is returned in Distribution
.
Attention
It is important to ensure that the region ConstRegion
is
not too close to a large gradient in the image, because the gradient
values are then used for calculating the mean. This means the
distance of ConstRegion
must be at least as large as the
filter size FilterSize
used for calculating the mean.
Execution Information
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Processed without parallelization.
Parameters
ConstRegion
(input_object) region(-array) →
object
Region from which the noise distribution is to be estimated.
Image
(input_object) singlechannelimage →
object (byte)
Corresponding image.
FilterSize
(input_control) integer →
(integer)
Size of the mean filter.
Default: 21
Suggested values: 5, 11, 15, 21, 31, 51, 101
Value range:
3
≤
FilterSize
≤
501
(lin)
Minimum increment: 2
Recommended increment: 2
Distribution
(output_control) distribution.values-array →
(real)
Noise distribution of all input regions.
Possible Predecessors
draw_region
,
gen_circle
,
gen_ellipse
,
gen_rectangle1
,
gen_rectangle2
,
threshold
,
erosion_circle
,
binomial_filter
,
gauss_filter
,
smooth_image
,
sub_image
Possible Successors
See also
mean_image
,
gauss_distribution
Module
Foundation