Canny edge detection in NPP can't seem to find it


I’ve just had a first look at the NVidia Performance Primitives library (NPP). The nVidia web pages advertise its feature set as including Canny Edge detection. In the documentation for the V1.0 release it seems to be a bit tricky to get to the pages mentioning edge detection.

When you enter the documentation for the “NPP Image Processing” module from the main index.html, you end up on this page which does not mention Canny at all file:///doc/html/group__nppi.html

However in the “Files” documentation for nppi.h header file the Canny features are mentioned.

To me it seems that the “Modules” documentation for image processing is a bit outdated and needs to be re-generated. Or for some reason it doesn’t pick up the Canny related functions as belonging to the Image Processing Module.

Please fix ;-) Also the funny spelling error “piexel” instead of “pixel”. This made me twietch a little ;)


PS: by the way, can we enable forum searches for 3 letter keywords, such as NPP?

Hi Christian,

thanks for the feedback. Both the issues you raised will be fixed in our next release. Canny documentation didn’t get picked up by Doxygen because of unbalanced number of braces.



I’m trying to use the Canny edge detector function provided with the NPP SDK but it seems to be incomplete. The Gaussian smoothing and first derivative computation along X and Y direction are missing (the function provided only accept the derivative as inputs). Does someone have implemented the missing step in CUDA ?

Thank you. :rolleyes:


Can you help me how to get SrcDx, SrcDxStep as well as SrcDy and SrcDyStep?

I’m trying to use canny function but there is still no document about it :(

Thanks very much