Operator Reference

HALCON Operator Reference / Filters / Noise
ClassesClasses | | Operators

add_noise_distributionT_add_noise_distributionAddNoiseDistributionAddNoiseDistributionadd_noise_distribution (Operator)

add_noise_distributionT_add_noise_distributionAddNoiseDistributionAddNoiseDistributionadd_noise_distribution — Add noise to an image.

Signature

add_noise_distribution(Image : ImageNoise : Distribution : )

Herror T_add_noise_distribution(const Hobject Image, Hobject* ImageNoise, const Htuple Distribution)

void AddNoiseDistribution(const HObject& Image, HObject* ImageNoise, const HTuple& Distribution)

HImage HImage::AddNoiseDistribution(const HTuple& Distribution) const

static void HOperatorSet.AddNoiseDistribution(HObject image, out HObject imageNoise, HTuple distribution)

HImage HImage.AddNoiseDistribution(HTuple distribution)

def add_noise_distribution(image: HObject, distribution: Sequence[float]) -> HObject

Description

add_noise_distributionadd_noise_distributionAddNoiseDistributionAddNoiseDistributionadd_noise_distribution adds noise distributed according to DistributionDistributionDistributiondistributiondistribution to the ImageImageImageimageimage. The resulting gray values are clipped to the range of the corresponding pixel type.

The DistributionDistributionDistributiondistributiondistribution is stored in a tuple of length 513. The individual values of this tuple define the frequency of noise with a specific amplitude defined by the position within the tuple. The central value, i.e., the value at the position 256 in the tuple defines the frequency of pixels that are not changed. The value at the position 255 defines the frequency of pixels for which the grayvalue is decreased by 1. The value at the position 254 defines the respective frequency for a grayvalue decrease of 2, and so on. Analogously, the value at position 257 defines the frequency of pixels for which the grayvalue is increased by 1.

The DistributionDistributionDistributiondistributiondistribution represents salt and pepper noise if at most one value at a position smaller than 256 is not equal to zero and at most one value at a position larger than 256 is not equal to zero. In case of salt and pepper noise, the added noisy pixels are set to the minimum (pepper) and maximum (salt) values that can be represented by ImageNoiseImageNoiseImageNoiseimageNoiseimage_noise if the amount of pepper is indicated by the value at position 0 and the amount of salt is indicated by the value at position 512 in the tuple.

The random noise is generated using the C function “drand48()”. See the parameter 'seed_rand'"seed_rand""seed_rand""seed_rand""seed_rand" of set_systemset_systemSetSystemSetSystemset_system for information on the used random seed.

Execution Information

  • Multithreading type: reentrant (runs in parallel with non-exclusive operators).
  • Multithreading scope: global (may be called from any thread).
  • Automatically parallelized on tuple level.
  • Automatically parallelized on channel level.

Parameters

ImageImageImageimageimage (input_object)  (multichannel-)image(-array) → objectHImageHObjectHObjectHobject (byte / int2)

Input image.

ImageNoiseImageNoiseImageNoiseimageNoiseimage_noise (output_object)  (multichannel-)image(-array) → objectHImageHObjectHObjectHobject * (byte / int2)

Noisy image.

Number of elements: ImageNoise == Image

DistributionDistributionDistributiondistributiondistribution (input_control)  distribution.values-array → HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)

Noise distribution.

Number of elements: 513

Example (HDevelop)

read_image(Image,'mreut')
dev_display (Image)
sp_distribution(30,30,Dist)
add_noise_distribution(Image,ImageNoise,Dist)
dev_display (ImageNoise)

Example (C)

read_image(&Image,"fabrik");
disp_image(Image,WindowHandle);
set_d(PerSalt,30.0,0);
set_d(PerPepper,30.0,0);
T_sp_distribution(PerSalt,PerPepper,&Dist);
T_add_noise_distribution(Image,&ImageNoise,Dist);
disp_image(ImageNoise,WindowHandle);

Example (HDevelop)

read_image(Image,'mreut')
dev_display (Image)
sp_distribution(30,30,Dist)
add_noise_distribution(Image,ImageNoise,Dist)
dev_display (ImageNoise)

Example (HDevelop)

read_image(Image,'mreut')
dev_display (Image)
sp_distribution(30,30,Dist)
add_noise_distribution(Image,ImageNoise,Dist)
dev_display (ImageNoise)

Result

add_noise_distributionadd_noise_distributionAddNoiseDistributionAddNoiseDistributionadd_noise_distribution returns 2 ( H_MSG_TRUE) if all parameters are correct. If the input is empty the behavior can be set via set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)set_system("no_object_result",<Result>). If necessary, an exception is raised.

Possible Predecessors

gauss_distributiongauss_distributionGaussDistributionGaussDistributiongauss_distribution, sp_distributionsp_distributionSpDistributionSpDistributionsp_distribution, noise_distribution_meannoise_distribution_meanNoiseDistributionMeanNoiseDistributionMeannoise_distribution_mean

Alternatives

add_noise_whiteadd_noise_whiteAddNoiseWhiteAddNoiseWhiteadd_noise_white

See also

sp_distributionsp_distributionSpDistributionSpDistributionsp_distribution, gauss_distributiongauss_distributionGaussDistributionGaussDistributiongauss_distribution, noise_distribution_meannoise_distribution_meanNoiseDistributionMeanNoiseDistributionMeannoise_distribution_mean, add_noise_whiteadd_noise_whiteAddNoiseWhiteAddNoiseWhiteadd_noise_white

Module

Foundation

ClassesClasses | | Operators