Implementation of 2D convolution using Fast Fourier Transformation (FFT). Convolution in time space is equal to multiplication in Frequency space.
This equation is expressed below.
The FFTW3 library in external_lib is compiled for Windows. For Ubuntu, FFTW 3.3.5 should be installed.
Run steps for Windows:
mkdir build && cd build
copy ..\external_lib\fftw-3.3.5-dll64\libfftw3f-3.dll .
cmake ..
makeOr run with Clion
Note: A copy of libfftw3f-3.dll must be in the executable directory
✅ full: (default) returns the full 2-D convolution
✅ same: returns the central part of the convolution that is the same size as "input"(using zero padding)
✅ valid: returns only those parts of the convolution that are computed without the zero - padded edges.
| full | same | valid |
|---|---|---|
 |
 |
 |
This process may faster than Time Domain Convolution. When using large images (exp: 1024 x 1024 or 512 x 512 etc.) is about 2 times faster than Time Domain Convolution. This measurement is based on trial and error, you should observe speed up yourself.
Example usage of FFTConv2D() function is specified in main.