OpenCV GPU ( CUDA ) Template matching and FFT implementation

Question

I am using opencv GPU::matchTemplate() on GTX690.

I checked the function internally and found that gpu::matchTemplate() is not using any FFT in the process, while its CPU counterpart does.

My question is, what is the reason behind not using FFT in the GPU?

Answer 1

如果模板大小大于某个阈值（ https://github.com/Itseez/opencv/blob/2.4/modules/gpu/src/match_template.cpp#L147 ），则OpenCV GPU匹配模板实现将使用FFT；否则，将使用brute-强制方法