algorithm - Time complexity of Canny edge detector -

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i writing research paper new steganography algorithm. have used canny edge detector @ point in algorithm. in paper need write time complexity of novel approach, in turns depends on time complexity of canny edge detector.

problem on web find reference time complexity of canny. i've read original canny paper. unable deduce , need here.

canny edge detection consists of

  1. a convolution of image blur kernel,
  2. four convolutions of image edge detector kernels,
  3. computation of gradient direction,
  4. non-maximum suppression, and
  5. thresholding hysteresis,

steps (1), (2), (3), , (4) implemented in terms of convolutions of image kernels of fixed size. using fft, it's possible implement convolutions in time o(n log n), n number of elements. if image has dimensions m × n, time complexity o(mn log mn) these steps.

the final step works postprocessing image remove high , low values, dropping other pixels aren't near other pixels. can done in time o(mn).

therefore, overall time complexity o(mn log mn).

hope helps!


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