The original image.
Result of applying the Sobel edge detector to
ren1.
The normalized result of applying the Sobel
edge detector to a scaled version (i.e. intensity
reduction by a factor of 4) of ren1.
Result of applying the Canny edge detector
(Gaussian smoothing standard deviation = 1, upper threshold = 255,
lower threshold = 1) to ren1.
Result of applying the Canny edge detector
(Gaussian smoothing standard deviation = 1.8, upper threshold = 255,
lower threshold = 1) to ren1.
Result of applying the Canny edge detector
(Gaussian smoothing standard deviation = 1.8, upper threshold = 200,
lower threshold = 1) to a scaled version (i.e. intensity
reduction by a factor of 4) of ren1.