canny
finds edges in an image using the Canny algorithm.
canny(image, threshold1, threshold2, aperture_size = 3, L2_gradient = FALSE)
An Image
object.
A numeric indicating the first threshold for the hysteresis procedure
A numeric indicating the second threshold for the hysteresis procedure
Aperture size for the Sobel operator (default: 3).
A logical flag, indicating whether a more accurate L2 norm should be used to calculate the image gradient magnitude, or whether the default L1 norm is enough (default: FALSE).
Canny J. A computational approach to edge detection. IEEE Trans Pattern Anal Mach Intell. 1986;8: 679<U+2013>698. doi:10.1109/TPAMI.1986.4767851