components.fft.fft
Compute Fourier transform. |
|
Convert output of |
- class FFT(config={}, **kwds)[source]
Bases:
Transformer
Compute Fourier transform.
The image can be divided into (non-overlapping) tiles of any size. It is padded out to an integer number of tiles in each direction. If you need overlapping tiles, preprocess your images with the
Tile
component. If you want to window the data before computing the FFT, use theModulate
component with a window function fromwindow
.Inputs can be real or complex. The output type is set by the
output
config value.The
VisualiseFFT
component can be used to convert the (complex) Fourier transform of a picture into a viewable image.The
submean
option can be used to reduce the amplitude of the “zero frequency” output bin. This can reduce leakage that might mask nearby low amplitude frequencies.Config
xtile
int
Horizontal tile size. If zero a single tile the width of the picture is used.
ytile
int
Vertical tile size. If zero a single tile the height of the picture is used.
inverse
bool
FFT or IFFT.
submean
bool
Subtract mean value of each tile before computing FFT.
output
str
Can be set to
complex
orreal
.
- VisualiseFFT(config={})[source]
Convert output of
FFT
to a viewable image.Computes the logarithmic magnitude of a complex FT and scales to 0..255 range.
Comments or questions? Please email jim@jim-easterbrook.me.uk.