ContourDetect

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

ContourDetect[image, delta] treats values in image that are smaller in absolute value than delta as zero.

ContourDetect[array, ...] gives a binary sparse array in which 1 corresponds to zeros and zero crossings in array.

Examples

Detect contours in an image:

ContourDetect[img]

Please visit the official Wolfram Language Reference for more details.