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BUILT-IN MATHEMATICA SYMBOL
CrossingDetect
CrossingDetect[image]
gives a binary image in which white pixels correspond to the zero crossings in image.
CrossingDetect[image, delta]
treats values in image that are smaller in absolute value than delta as zero.
Details and Options
- CrossingDetect finds pixels with positive values that have at least one negative neighbor.
- CrossingDetect is typically used in edge-detection algorithms based on second derivatives.
- CrossingDetect works with images of arbitrary type.
- CrossingDetect will only find zero crossings when applied to images of type
. - For color images, CrossingDetect operates on the intensity averaged over all channels.
- CrossingDetect[m] finds zero crossings in a numerical matrix m, returning a sparse array.
- CrossingDetect[m, delta] effectively chops values smaller in magnitude than delta.
- CrossingDetect by default treats all eight pixels surrounding a given pixel as adjacent.
- The option setting CornerNeighbors->False treats only the four pixels in the coordinate directions as adjacent.
- Using the option setting CornerNeighbors->None, CrossingDetect operates on the dual grid whose pixels correspond to the corners in the original image, thereby reducing the dimensions of the resulting image by one pixel.
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