Name
fast_thresholdfast_thresholdFastThresholdfast_thresholdFastThresholdFastThreshold — Fast thresholding of images using global thresholds.
fast_thresholdfast_thresholdFastThresholdfast_thresholdFastThresholdFastThreshold selects the pixels from the input image
whose gray values g fulfill the following condition:
To reduce the processing time, the selection is done in two steps: At first,
all points lying on selected horizontal lines that are specified by their
distance MinSizeMinSizeMinSizeMinSizeMinSizeminSize are processed. In the next step the neighborhood
(size (2*MinSize+1) x
(2*MinSize+1)) of all previously selected points are
processed.
On multicore computers supporting the SSE2 instruction set, thresholdthresholdThresholdthresholdThresholdThreshold
is most likely faster than fast_thresholdfast_thresholdFastThresholdfast_thresholdFastThresholdFastThreshold.
fast_thresholdfast_thresholdFastThresholdfast_thresholdFastThresholdFastThreshold may only be preferred to thresholdthresholdThresholdthresholdThresholdThreshold if those
features are not available, e.g. on embedded platforms.
- 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 internal data level.
Lower threshold for the gray values.
Default value: 128
Suggested values: 0.0, 10.0, 30.0, 64.0, 128.0, 200.0, 220.0, 255.0
Typical range of values: 0.0
≤
MinGray
MinGray
MinGray
MinGray
MinGray
minGray
≤
255.0 (lin)
Minimum increment: 1
Recommended increment: 5.0
Upper threshold for the gray values.
Default value: 255.0
Suggested values: 0.0, 10.0, 30.0, 64.0, 128.0, 200.0, 220.0, 255.0
Typical range of values: 0.0
≤
MaxGray
MaxGray
MaxGray
MaxGray
MaxGray
maxGray
≤
255.0 (lin)
Minimum increment: 1
Recommended increment: 5.0
Minimum size of objects to be extracted.
Default value: 20
Suggested values: 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 100
Typical range of values: 2
≤
MinSize
MinSize
MinSize
MinSize
MinSize
minSize
≤
200 (lin)
Minimum increment: 1
Recommended increment: 2
Let A be the area of the output region and height the
height of ImageImageImageImageImageimage. Then the runtime
complexity is O(A + height / MinSizeMinSizeMinSizeMinSizeMinSizeminSize).
fast_thresholdfast_thresholdFastThresholdfast_thresholdFastThresholdFastThreshold returns 2 (H_MSG_TRUE) if all parameters are correct.
The behavior with respect to the input images and output regions
can be determined by setting the values of the flags
'no_object_result'"no_object_result""no_object_result""no_object_result""no_object_result""no_object_result", 'empty_region_result'"empty_region_result""empty_region_result""empty_region_result""empty_region_result""empty_region_result", and
'store_empty_region'"store_empty_region""store_empty_region""store_empty_region""store_empty_region""store_empty_region" with set_systemset_systemSetSystemset_systemSetSystemSetSystem.
If necessary, an exception is raised.
histo_to_threshhisto_to_threshHistoToThreshhisto_to_threshHistoToThreshHistoToThresh,
min_max_graymin_max_grayMinMaxGraymin_max_grayMinMaxGrayMinMaxGray,
sobel_ampsobel_ampSobelAmpsobel_ampSobelAmpSobelAmp,
binomial_filterbinomial_filterBinomialFilterbinomial_filterBinomialFilterBinomialFilter,
gauss_filtergauss_filterGaussFiltergauss_filterGaussFilterGaussFilter,
reduce_domainreduce_domainReduceDomainreduce_domainReduceDomainReduceDomain,
fill_interlacefill_interlaceFillInterlacefill_interlaceFillInterlaceFillInterlace
connectionconnectionConnectionconnectionConnectionConnection,
dilation1dilation1Dilation1dilation1Dilation1Dilation1,
erosion1erosion1Erosion1erosion1Erosion1Erosion1,
openingopeningOpeningopeningOpeningOpening,
closingclosingClosingclosingClosingClosing,
rank_regionrank_regionRankRegionrank_regionRankRegionRankRegion,
shape_transshape_transShapeTransshape_transShapeTransShapeTrans,
skeletonskeletonSkeletonskeletonSkeletonSkeleton
thresholdthresholdThresholdthresholdThresholdThreshold,
gen_grid_regiongen_grid_regionGenGridRegiongen_grid_regionGenGridRegionGenGridRegion,
dilation_rectangle1dilation_rectangle1DilationRectangle1dilation_rectangle1DilationRectangle1DilationRectangle1,
dyn_thresholddyn_thresholdDynThresholddyn_thresholdDynThresholdDynThreshold
class_2dim_supclass_2dim_supClass2dimSupclass_2dim_supClass2dimSupClass2dimSup,
hysteresis_thresholdhysteresis_thresholdHysteresisThresholdhysteresis_thresholdHysteresisThresholdHysteresisThreshold
Foundation