zero_crossingzero_crossingZeroCrossingZeroCrossingzero_crossing (算子名称)

名称

zero_crossingzero_crossingZeroCrossingZeroCrossingzero_crossing — Extract zero crossings from an image.

参数签名

描述

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.

运行信息

• 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.

参数表

结果

zero_crossingzero_crossingZeroCrossingZeroCrossingZeroCrossingzero_crossing usually returns the value 2 ( H_MSG_TRUE) . If necessary, an exception is raised.

可能的前置算子

laplacelaplaceLaplaceLaplaceLaplacelaplace, laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss, derivate_gaussderivate_gaussDerivateGaussDerivateGaussDerivateGaussderivate_gauss

可能的后置算子

connectionconnectionConnectionConnectionConnectionconnection, skeletonskeletonSkeletonSkeletonSkeletonskeleton, boundaryboundaryBoundaryBoundaryBoundaryboundary, select_shapeselect_shapeSelectShapeSelectShapeSelectShapeselect_shape, fill_upfill_upFillUpFillUpFillUpfill_up

可替代算子

thresholdthresholdThresholdThresholdThresholdthreshold, dual_thresholddual_thresholdDualThresholdDualThresholdDualThresholddual_threshold, zero_crossing_sub_pixzero_crossing_sub_pixZeroCrossingSubPixZeroCrossingSubPixZeroCrossingSubPixzero_crossing_sub_pix

模块

Foundation