noise_distribution_meanT_noise_distribution_meanNoiseDistributionMeannoise_distribution_meanNoiseDistributionMeanNoiseDistributionMean (Operator)

Name

noise_distribution_meanT_noise_distribution_meanNoiseDistributionMeannoise_distribution_meanNoiseDistributionMeanNoiseDistributionMean — Determine the noise distribution of an image.

Signature

noise_distribution_mean(ConstRegion, Image : : FilterSize : Distribution)

noise_distribution_meannoise_distribution_meanNoiseDistributionMeannoise_distribution_meanNoiseDistributionMeanNoiseDistributionMean calculates the noise distribution in a region of the image ImageImageImageImageImageimage. The parameter ConstRegionConstRegionConstRegionConstRegionConstRegionconstRegion 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_imagemean_imageMeanImagemean_imageMeanImageMeanImage 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 DistributionDistributionDistributionDistributionDistributiondistribution.

Attention

It is important to ensure that the region ConstRegionConstRegionConstRegionConstRegionConstRegionconstRegion 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 ConstRegionConstRegionConstRegionConstRegionConstRegionconstRegion must be at least as large as the filter size FilterSizeFilterSizeFilterSizeFilterSizeFilterSizefilterSize used for calculating the mean.

Parallelization

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Processed without parallelization.

Parameters

ConstRegionConstRegionConstRegionConstRegionConstRegionconstRegion (input_object) region(-array) → object

Region from which the noise distribution is to be estimated.

ImageImageImageImageImageimage (input_object) singlechannelimage → object (byte)

Corresponding image.

FilterSizeFilterSizeFilterSizeFilterSizeFilterSizefilterSize (input_control) integer → (integer)

Size of the mean filter.

Default value: 21

Suggested values: 5, 11, 15, 21, 31, 51, 101

Typical range of values: 3 ≤ FilterSize FilterSize FilterSize FilterSize FilterSize filterSize ≤ 501 (lin)

Minimum increment: 2

Recommended increment: 2

DistributionDistributionDistributionDistributionDistributiondistribution (output_control) distribution.values-array → (real)

Noise distribution of all input regions.

Possible Predecessors

draw_regiondraw_regionDrawRegiondraw_regionDrawRegionDrawRegion, gen_circlegen_circleGenCirclegen_circleGenCircleGenCircle, gen_ellipsegen_ellipseGenEllipsegen_ellipseGenEllipseGenEllipse, gen_rectangle1gen_rectangle1GenRectangle1gen_rectangle1GenRectangle1GenRectangle1, gen_rectangle2gen_rectangle2GenRectangle2gen_rectangle2GenRectangle2GenRectangle2, thresholdthresholdThresholdthresholdThresholdThreshold, erosion_circleerosion_circleErosionCircleerosion_circleErosionCircleErosionCircle, binomial_filterbinomial_filterBinomialFilterbinomial_filterBinomialFilterBinomialFilter, gauss_filtergauss_filterGaussFiltergauss_filterGaussFilterGaussFilter, smooth_imagesmooth_imageSmoothImagesmooth_imageSmoothImageSmoothImage, sub_imagesub_imageSubImagesub_imageSubImageSubImage

Possible Successors

add_noise_distributionadd_noise_distributionAddNoiseDistributionadd_noise_distributionAddNoiseDistributionAddNoiseDistribution

Module

Foundation

Operators