Discrete Cosine Transform
DESCRIPTION:
Performs the discrete cosine transform (DCT) on a vector or a matrix.
USAGE
:
dct(x, type=2, inv=F) dct.2d(x, type=2, inv=F)
REQUIRED ARGUMENTS
:
x
:
a vector, or a matrix.
OPTIONAL ARGUMENTS
:
type
:
one of the integers
2
or
4
, indicating the discrete cosine transfer type, DCT-II or DCT-IV, to use. See below for details.
inv
:
logical flag: if
TRUE
, the inverse of the transform os computed.
VALUE
:
the normalized discrete cosine transform of te input data
x
(or the inverse transform if
inv=TRUE
). This is of the same length and mode as
x
.
DETAILS:
See the printed help file for the definitions of DCT-II and DCT-IV and their inverses.
REFERENCES:
Rao, K. R. and Yip, P. (1990).
Discrete Cosine Transform: Algorithms, Advantages, Applications.
Academic Press, Inc., San Diego, CA
SEE ALSO:
cp.table
,
cpt
,
cpt.2d
.