WTFwdInit
Initializes the forward wavelet transform context structure.
Syntax
IppStatus ippiWTFwdInit_32f_C1R(IppiWTFwdSpec_32f_C1R*
pSpec
, const Ipp32f*
pTapsLow
, int
lenLow
, int
anchorLow
, const Ipp32f*
pTapsHigh
, int
lenHigh
, int
anchorHigh
);
IppStatus ippiWTFwdInit_32f_C3R(IppiWTFwdSpec_32f_C3R*
pSpec
, const Ipp32f*
pTapsLow
, int
lenLow
, int
anchorLow
, const Ipp32f*
pTapsHigh
, int
lenHigh
, int
anchorHigh
);
Include Files
ippi.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
,
ipps.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
Parameters
- pSpec
- Double pointer to the forward wavelet transform specification structure.
- pTapsLow
- Pointer to lowpass filter taps.
- lenLow
- Length of the lowpass filter.
- anchorLow
- Anchor position of the lowpass filter.
- pTapsHigh
- Pointer to highpass filter taps.
- lenHigh
- Length of the highpass filter.
- anchorHigh
- Anchor position of the highpass filter.
Description
This function initializes the specification structure
pSpec
for a one-level wavelet decomposition.
The forward wavelet transform specification structure contains parameters of a wavelet filter bank used for image decomposition. The filter bank consists of two analysis filters and includes the lowpass decomposition filter (or
coarse
filter) and the highpass decomposition filter (or
detail
filter).
The parameters
pTapsLow
and
pTapsHigh
specify coefficients, and
anchorLow
and
anchorHigh
- anchor positions for two synthesis filters. The anchor value sets the initial leftmost filter position relative to image row or column as shown in the figure below:
Anchor Value and Initial Filter Position for Wavelet Decomposition
Here
a
stands for anchor value,
N
is filter length, x
0
is the starting pixel of the processed row or column, and x
-1
, x
-2
,... are the additional border pixels that are needed for calculations. The anchor value and filter length completely determine right, left, top, and bottom border sizes for the source image used in decomposition. The corresponding C-language expressions to calculate border sizes are given in the description of ippiWTFwd
function.
For an example on how to use this function, refer to the example provided with the
ippiWTInv
function description.
Return Values
- ippStsNoErr
- Indicates no error. Any other value indicates an error or a warning.
- ippStsNullPtrErr
- Indicates an error when any of the specified pointers isNULL.
- ippStsNumChannelsErr
- Indicates an error whennumChannelshas an illegal value.
- ippStsSizeErr
- Indicates an error when filter lengthlenLoworlenHighis less than 2.
- ippStsAnchorErr
- Indicates an error when anchor positionanchorLoworanchorHighis less than zero.