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Legacy Documentation
Digital Image Processing
(2000)
This is documentation for an obsolete product.
Current products and services
Function Index
DiscreteCosineTransform
DiscreteCosineTransform[
img
]
returns the discrete cosine transform (DCT) of
img
.
DiscreteCosineTransform[
img
,
{n
1
,
n
2
,
...}
]
returns the DCT of a zero-padded
img
with dimensions n
1
×n
2
×....
The 1D DCT of a sequence x[n] of length N is defined as
for k = 0,1,...,N-1
The 2D DCT is defined as
for k
1
= 0,1,...,N
1
-1 and k
2
= 0,1,...,N
2
-1,
where
The argument
img
may be a vector, matrix, or
ImageData
expression.
See also User's Guide
8.4
,
8.8
.
Example
This loads the package.
In[1]:=
This computes and displays the DCT of a bright rectangle on a dark background.
In[2]:=
Out[2]=
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