Developer Reference

  • 2020
  • 10/21/2020
  • Public Content
Contents

DFTInv

Applies an inverse DFT to complex source data and stores results in a destination image.

Syntax

Case
1
: Not-in-place operation on floating-point data
IppStatus ippiDFTInv_PackToR_<mod>(const Ipp32f*
pSrc
, int
srcStep
, Ipp32f*
pDst
, int
dstStep
, const IppiDFTSpec_R_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
Supported values for
mod
:
32f_C1R
32f_C3R
32f_C4R
32f_AC4R
Case
2
: Not-in-place operation on complex data
IppStatus ippiDFTInv_CToC_32fc_C1R(const Ipp32fc*
pSrc
, int
srcStep
, Ipp32fc*
pDst
, int
dstStep
, const IppiDFTSpec_C_32fc*
pDFTSpec
, Ipp8u*
pBuffer
);
Case
3
: In-place operation on floating-point data
IppStatus ippiDFTInv_PackToR_<mod>(Ipp32f*
pSrcDst
, int
srcDstStep
, const IppiDFTSpec_R_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
Supported values for
mod
:
32f_C1IR
32f_C3IR
32f_C4IR
32f_AC4IR
Case 5: In-place operation on complex data
IppStatus ippiDFTInv_CToC_32fc_C1IR(Ipp32fc*
pSrcDst
, int
srcDstStep
, const IppiDFTSpec_C_32fc*
pDFTSpec
, Ipp8u*
pBuffer
);
Include Files
ippi.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
,
ipps.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
Parameters
pSrc
Pointer to the source image ROI.
srcStep
Distance in bytes between starts of consecutive lines in the source image.
pDst
Pointer to the destination image ROI.
dstStep
Distance in bytes between starts of consecutive lines in the destination image.
pSrcDst
Pointer to the source and destination image ROI for the in-place operation.
srcDstStep
Distance in bytes between starts of consecutive lines in the source and destination image for the in-place operation.
pDFTSpec
Pointer to the previously initialized DFT context structure.
pBuffer
Pointer to the external work buffer.
Description
This function operates with ROI.
This function performs an inverse DFT on each channel of the input buffer
pSrc
(
pSrcDst
for in-place flavors) and writes the restored image data into the corresponding channel of the output image buffer
pDst
(
pSrcDst
for in-place flavors).
For function flavor
ippiDFTInv_PackToR,
the input buffer must contain data in RCPack2D format.
Before using the inverse DFT functions, you need to compute the size of the work buffer by
ippiDFTGetSize
and initialize the context structure by the
ippiDFTInit
function. The inverse DFT functions use the
pDFTSpec
context structure to set the mode of calculations and retrieve support data.
Return Values
ippStsNoErr
Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr
Indicates an error condition if
pSrc, pDst,
or
pDFTSpec
pointer is
NULL
.
ippStsStepErr
Indicates an error condition if
srcStep
or
dstStep
value is zero or negative.
ippStsContextMatchErr
Indicates an error condition if a pointer to an invalid
pDFTSpec
structure is passed.
ippStsMemAllocErr
Indicates an error condition if memory allocation fails.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804