median_weightedmedian_weightedmedian_weightedMedianWeightedMedianWeighted (Operator)

Name

median_weightedmedian_weightedmedian_weightedMedianWeightedMedianWeighted — Weighted median filtering with different rank masks.

Signature

Description

The operator median_weightedmedian_weightedmedian_weightedMedianWeightedMedianWeighted calculates the median of the gray values within a local environment. In contrast to median_imagemedian_imagemedian_imageMedianImageMedianImage, which uses all gray values within the environment exactly once, the operator median_weightedmedian_weightedmedian_weightedMedianWeightedMedianWeighted weights all gray values several times depending on their position. A gray value is received into the field to be sorted several times according to its weighting. The following masks are available:

'gauss'

(MaskSizeMaskSizeMaskSizeMaskSizemaskSize = 3)

1 2 1
2 4 2
1 2 1

'inner'

(MaskSizeMaskSizeMaskSizeMaskSizemaskSize = 3)

1 1 1
1 3 1
1 1 1

The operator median_weightedmedian_weightedmedian_weightedMedianWeightedMedianWeighted means that, contrary to median_imagemedian_imagemedian_imageMedianImageMedianImage, gray value corners remain.

Parallelization

• 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.
• Automatically parallelized on domain level.

Parameters

read_image(Image,'fabrik')
median_weighted(Image,MedianWeighted,'gauss',3)
disp_image(MedianWeighted,WindowHandle)

read_image(&Image,"fabrik");
median_weighted(Image,&MedianWeighted,"gauss",3);
disp_image(MedianWeighted,WindowHandle);

read_image(Image,'fabrik')
median_weighted(Image,MedianWeighted,'gauss',3)
disp_image(MedianWeighted,WindowHandle)

read_image(Image,'fabrik')
median_weighted(Image,MedianWeighted,'gauss',3)
disp_image(MedianWeighted,WindowHandle)

read_image(Image,'fabrik')
median_weighted(Image,MedianWeighted,'gauss',3)
disp_image(MedianWeighted,WindowHandle)

Complexity

For each pixel: O(F * log(F)) with F = area of MaskTypeMaskTypeMaskTypeMaskTypemaskType.

Possible Predecessors

read_imageread_imageread_imageReadImageReadImage

Possible Successors

thresholdthresholdthresholdThresholdThreshold, dyn_thresholddyn_thresholddyn_thresholdDynThresholdDynThreshold, regiongrowingregiongrowingregiongrowingRegiongrowingRegiongrowing

Alternatives

median_imagemedian_imagemedian_imageMedianImageMedianImage, trimmed_meantrimmed_meantrimmed_meanTrimmedMeanTrimmedMean, sigma_imagesigma_imagesigma_imageSigmaImageSigmaImage

References

R. Haralick, L. Shapiro; “Computer and Robot Vision”; Addison-Wesley, 1992, Seite 319

Module

Foundation