trimmed_meantrimmed_meantrimmed_meanTrimmedMeanTrimmedMean (Operator)

Name

trimmed_meantrimmed_meantrimmed_meanTrimmedMeanTrimmedMean — Smooth an image with an arbitrary rank mask.

Signature

Description

The operator trimmed_meantrimmed_meantrimmed_meanTrimmedMeanTrimmedMean carries out a non-linear smoothing of the gray values of all input images (ImageImageImageImageimage). The filter mask (MaskMaskMaskMaskmask) is passed in the form of a region. The average of NumberNumberNumberNumbernumber gray values located near the median is calculated. Several border treatments can be chosen for filtering (MarginMarginMarginMarginmargin):

    gray value   Pixels outside of the image edges
                 are assumed to be constant (with the
                 indicated gray value).
    'continued'  Continuation of edge pixels.
    'cyclic'     Cyclic continuation of image edges.
    'mirrored'   Reflection of pixels at the image edges.

The indicated mask (= region of the mask image) is put over the image to be filtered in such a way that the center of the mask touches all pixels once. For each of these pixels all neighboring pixels covered by the mask are sorted in an ascending sequence according to their gray values. Thus, each of these sorted gray value sequences contains exactly as many gray values as the mask has pixels. If F is the area of the mask the average of these sequences is calculated as follows: The first (F - Number)/2 gray values are ignored. Then the following NumberNumberNumberNumbernumber gray values are summed up and divided by NumberNumberNumberNumbernumber. Again the remaining (F - NumberNumberNumberNumbernumber)/2 gray values are ignored.

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')
draw_region(Region,WindowHandle)
trimmed_mean(Image,Region,TrimmedMean,5,'mirrored')
disp_image(TrimmedMean,WindowHandle)

read_image(&Image,"fabrik");
draw_region(&Region,WindowHandle);
trimmed_mean(Image,Region,&TrimmedMean,5,"mirrored");
disp_image(TrimmedMean,WindowHandle);

read_image(Image,'fabrik')
draw_region(Region,WindowHandle)
trimmed_mean(Image,Region,TrimmedMean,5,'mirrored')
disp_image(TrimmedMean,WindowHandle)

read_image(Image,'fabrik')
draw_region(Region,WindowHandle)
trimmed_mean(Image,Region,TrimmedMean,5,'mirrored')
disp_image(TrimmedMean,WindowHandle)

read_image(Image,'fabrik')
draw_region(Region,WindowHandle)
trimmed_mean(Image,Region,TrimmedMean,5,'mirrored')
disp_image(TrimmedMean,WindowHandle)

Result

If the parameter values are correct the operator trimmed_meantrimmed_meantrimmed_meanTrimmedMeanTrimmedMean returns the value 2 (H_MSG_TRUE). The behavior in case of empty input (no input images available) is set via the operator set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>). If necessary an exception is raised.

Possible Predecessors

read_imageread_imageread_imageReadImageReadImage, draw_regiondraw_regiondraw_regionDrawRegionDrawRegion, gen_circlegen_circlegen_circleGenCircleGenCircle, gen_rectangle1gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1

Possible Successors

thresholdthresholdthresholdThresholdThreshold, dyn_thresholddyn_thresholddyn_thresholdDynThresholdDynThreshold, regiongrowingregiongrowingregiongrowingRegiongrowingRegiongrowing

Alternatives

sigma_imagesigma_imagesigma_imageSigmaImageSigmaImage, median_weightedmedian_weightedmedian_weightedMedianWeightedMedianWeighted, median_imagemedian_imagemedian_imageMedianImageMedianImage

See also

gen_circlegen_circlegen_circleGenCircleGenCircle, gen_rectangle1gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1, gray_erosion_rectgray_erosion_rectgray_erosion_rectGrayErosionRectGrayErosionRect, gray_dilation_rectgray_dilation_rectgray_dilation_rectGrayDilationRectGrayDilationRect

References

R. Haralick, L. Shapiro; “Computer and Robot Vision”; Addison-Wesley, 1992, Seite 320

Module

Foundation