Edge extraction after having derivatives in x and y


Suppose that I have already taken the derivatives in x and y of an image, dx and dy for example.
How can I extract edges with dx and dy if I don’t want to use canny.
Thank you.

have a look at Sobel filters

Thanks @berak. It simply calculates a weighted sum but what if I want to get the final edge image such as a result of canny.
It should be a binary image.

so… you want to reimplement canny? or you want us to come up with something that looks like canny but isn’t? or…? do you want us to show you how to threshold a picture?

that’s what the sample does. you dont have to do the same

just look at the straight Sobel output

OK, get it. Threshold!