zero_crossingzero_crossingZeroCrossingZeroCrossingzero_crossing (Operator)
Name
zero_crossingzero_crossingZeroCrossingZeroCrossingzero_crossing — Extract zero crossings from an image.
Signature
def zero_crossing(image: HObject) -> HObject
Description
zero_crossingzero_crossingZeroCrossingZeroCrossingZeroCrossingzero_crossing returns the zero crossings of the input
image as a region. A pixel is accepted as a zero crossing if its
gray value (in ImageImageImageImageimageimage) is zero, or if at least one of its
neighbors of the 4-neighborhood has a different sign.
This operator is intended to be used after edge operators returning
the second derivative of the image (e.g., laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss),
which were possibly followed by a smoothing operator. In this case,
the zero crossings are (candidates for) edges.
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 domain level.
Parameters
ImageImageImageImageimageimage (input_object) singlechannelimage(-array) → objectHImageHObjectHImageHobject (int1 / int2 / int4 / real)
Input image.
RegionCrossingRegionCrossingRegionCrossingRegionCrossingregionCrossingregion_crossing (output_object) region(-array) → objectHRegionHObjectHRegionHobject *
Zero crossings.
Result
zero_crossingzero_crossingZeroCrossingZeroCrossingZeroCrossingzero_crossing usually returns the value 2 (H_MSG_TRUE). If
necessary, an exception is raised.
Possible Predecessors
laplacelaplaceLaplaceLaplaceLaplacelaplace,
laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss,
derivate_gaussderivate_gaussDerivateGaussDerivateGaussDerivateGaussderivate_gauss
Possible Successors
connectionconnectionConnectionConnectionConnectionconnection,
skeletonskeletonSkeletonSkeletonSkeletonskeleton,
boundaryboundaryBoundaryBoundaryBoundaryboundary,
select_shapeselect_shapeSelectShapeSelectShapeSelectShapeselect_shape,
fill_upfill_upFillUpFillUpFillUpfill_up
Alternatives
thresholdthresholdThresholdThresholdThresholdthreshold,
dual_thresholddual_thresholdDualThresholdDualThresholdDualThresholddual_threshold,
zero_crossing_sub_pixzero_crossing_sub_pixZeroCrossingSubPixZeroCrossingSubPixZeroCrossingSubPixzero_crossing_sub_pix
Module
Foundation