dct3D {MFPCA} | R Documentation |
Calculate and threshold DCT for an 3D image
Description
This function calculates the (orthonormal) discrete cosine
transformation for a 3D image and returns thresholded DCT coefficients
using the C-library fftw3
(see http://www.fftw.org/).
Usage
dct3D(image, qThresh)
Arguments
image |
A 3D image (a 3D array with real values). |
qThresh |
A numeric with value in |
Value
ind |
An integer vector, containing the indices of non-thresholded (hence non-zero) coefficients. |
val |
A numeric vector, giving the values of the corresponding coefficients. |
Warning
If the C-library fftw3
is not available when
the package MFPCA
is installed, this function is disabled an
will throw an error. For full functionality install the C-library
fftw3
from http://www.fftw.org/ and reinstall
MFPCA
. This function has not been tested with
ATLAS/MKL/OpenBLAS.