DGT2 2-D Discrete Gabor transform
Usage: c=dgt2(f,g,a,M);
c=dgt2(f,g1,g2,[a1,a2],[M1,M2]);
c=dgt2(f,g1,g2,[a1,a2],[M1,M2],[L1,L2]);
[c,Ls]=dgt2(f,g1,g2,[a1,a2],[M1,M2]);
[c,Ls]=dgt2(f,g1,g2,[a1,a2],[M1,M2],[L1,L2]);
Input parameters:
f : Input data, matrix.
g,g1,g2 : Window functions.
a,a1,a2 : Length of time shifts.
M,M1,M2 : Number of modulations.
L1,L2 : Length of transform to do
Output parameters:
c : array of coefficients.
Ls : Original size of input matrix.
DGT2(f,g,a,M) will calculate a separable two-dimensional discrete
Gabor transformation of the input signal f with respect to the window
g and parameters a and M.
For each dimension, the length of the transform will be the smallest
possible that is larger than the length of the signal along that dimension.
f will be appropriately zero-extended.
DGT2(f,g,a,M,L) computes a Gabor transform as above, but does
a transform of length L along each dimension. f will be cut or
zero-extended to length L before the transform is done.
[c,Ls]=DGT2(f,g,a,M) or [c,Ls]=DGT2(f,g,a,M,L) additionally returns
the length of the input signal f. This is handy for reconstruction:
[c,Ls]=dgt2(f,g,a,M);
fr=idgt2(c,gd,a,Ls);
will reconstruct the signal f no matter what the size of f is, provided
that gd is a dual window of g.
DGT2(f,g1,g2,a,M) makes it possible to use a different window along the
two dimensions.
The parameters a, M, L and Ls can also be vectors of length 2.
In this case the first element will be used for the first dimension
and the second element will be used for the second dimension.
The output c has 4 or 5 dimensions. The dimensions index the
following properties:
1. Number of translation along 1st dimension of input.
2. Number of channel along 1st dimension of input
3. Number of translation along 2nd dimension of input.
4. Number of channel along 2nd dimension of input
5. Plane number, corresponds to 3rd dimension of input.
Url: http://ltfat.github.io/doc/gabor/dgt2.html
See also: dgt, idgt2, gabdual.
Package: ltfat