gives a binary image in which white pixels correspond to the zeros and zero crossings in image.


treats values in image that are smaller in absolute value than delta as zero.


gives a binary sparse array in which 1 corresponds to zeros and zero crossings in array.

Details and Options

  • ContourDetect finds pixels with zero value as well as pixels with positive values that have at least one negative neighbor.
  • For color images, ContourDetect operates on the intensity averaged over all channels.
  • ContourDetect works with 3D as well as 2D images, and also with arrays of rank 1, 2, or 3.
  • ContourDetect[array,delta] effectively chops values smaller in magnitude than delta.
  • ContourDetect takes a CornerNeighbors option. The default setting is CornerNeighbors->True.
  • Using the option setting CornerNeighbors->None, ContourDetect 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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Basic Examples  (2)

Zeros and zero crossings of a list:

Click for copyable input

Find zeros and zero crossings in a real-valued image:

Click for copyable input

Scope  (3)

Options  (1)

Applications  (2)

Properties & Relations  (2)

See Also

CrossingDetect  Threshold  MorphologicalPerimeter

Introduced in 2010
| Updated in 2014