Decomposition coefficients, returned as an
*N*-by-1 cell array, where
*N* equals 7 `wdec.level`

+1.

`dec{1}`

contains the lowpass component
(approximation) at the level of the decomposition. The
approximation is equivalent to the filtering operations
`'LLL'`

.

`dec{k+2},...,dec{k+8}`

with ```
k =
0,7,14,...,7*(wdec.level-1)
```

contain the 3-D
wavelet coefficients for the multiresolution starting with the
coarsest level when `k=0`

.

For example, if `wdec.level=3`

,
`dec{2},...,dec{8}`

contain the wavelet
coefficients for level 3 (`k=0`

),
`dec{9},...,dec{15}`

contain the wavelet
coefficients for level 2 (`k=7`

), and
`dec{16},...,dec{22}`

contain the wavelet
coefficients for level 1
(`k=7*(wdec.level-1)`

).

At each level, the wavelet coefficients in
`dec{k+2},...,dec{k+8}`

are in the
following order:
`'HLL'`

,`'LHL'`

,`'HHL'`

,`'LLH'`

,`'HLH'`

,`'LHH'`

,`'HHH'`

.

The sequence of letters gives the order in which the separable
filtering operations are applied from left to right. For
example, `'LHH'`

means that the lowpass
(scaling) filter with downsampling is applied to the rows of
`x`

, followed by the highpass (wavelet)
filter with downsampling applied to the columns of
`x`

. Finally, the highpass filter with
downsampling is applied to the 3rd dimension of
`x`

.