CODEWITHSUNDEEP
opencv
smcs
smcs

Reputation: 2004

OpenCV: DFT takes much longer after recompilation

I recently recompiled OpenCV 3.2.0 on my Ubuntu 16.04 machine to include CUDA. For some reason, the cv::dft() now takes about 30 seconds for a certain image instead of 5 seconds before compilation. This is catastrophic as I need to run it a lot of times. What could be the reason for this change? Are there some compiler flags I might have missed?

Upvotes: 1

Views: 214

Answers (1)

smcs
smcs

Reputation: 2004

I can't say for sure but it seems the necessary flag that I had not activated was WITH_IPP=ON. DFT now runs ten times faster, after I recompiled.

As a side note, padding can make a huge difference as well, as explained here: https://docs.opencv.org/2.4/doc/tutorials/core/discrete_fourier_transform/discrete_fourier_transform.html

Upvotes: 1

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