Intel® Integrated Performance Primitives Developer Reference

Developer Reference

  • 2021
  • 01/15/2021
  • Public Content
Contents

LShiftC

Shifts bits in pixel values to the left.

Syntax

Case 1: Not-in-place operation on one-channel data
IppStatus ippiLShiftC_<mod>
(
const Ipp<datatype>*
pSrc
,
int
srcStep
,
Ipp32u
value
,
Ipp<datatype>*
pDst
,
int
dstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_C1R
16u_C1R
32s_C1R
Case 2: Not-in-place operation on multi-channel data
IppStatus ippiLShiftC_<mod>
(
const Ipp<datatype>*
pSrc
,
int
srcStep
,
const Ipp32u
value
[3]
,
Ipp<datatype>*
pDst
,
int
dstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_C3R
16u_C3R
32s_C3R
32s_AC4R
8u_AC4R
16u_AC4R
IppStatus ippiLShiftC_<mod>
(
const Ipp<datatype>*
pSrc
,
int
srcStep
,
const Ipp32u
value
[4]
,
Ipp<datatype>*
pDst
,
int
dstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_C4R
16u_C4R
32s_C4R
Case 3: In-place operation on one-channel data
IppStatus ippiLShiftC_<mod>
(
Ipp32u
value
,
Ipp<datatype>*
pSrcDst
,
int
srcDstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_C1IR
16u_C1IR
32s_C1IR
Case 4: In-place operation on multi-channel data
IppStatus ippiLShiftC_<mod>
(
const Ipp32u
value
[3]
,
Ipp<datatype>*
pSrcDst
,
int
srcDstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_C3IR
16u_C3IR
32s_C3IR
8u_AC4IR
16u_AC4IR
32s_AC4IR
IppStatus ippiLShiftC_<mod>
(
const Ipp32u
value
[4]
,
Ipp<datatype>*
pSrcDst
,
int
srcDstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_C4IR
16u_C4IR
32s_C4IR
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.
value
The number of bits to shift (constant vector in case of multi-channel images).
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.
roiSize
Size of the source and destination ROI in pixels.
Description
This function operates with ROI (see Regions of Interest in Intel IPP).
This function changes the intensity of pixels in the source image ROI by shifting the bits in each pixel value by
value
 bits to the left. In case of multi-channel data, each color channel can have its own shift value. The positions vacated after shifting the bits are filled with zeros. Values obtained as a result of left shift operations are not saturated. To get saturated values, use multiplication functions instead.
Note that the functions with the
AC4
 descriptor do not process alpha channels.
Return Values
ippStsNoErr
Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr
Indicates an error condition if one of the specified pointers is
NULL
.
ippStsSizeErr
Indicates an error condition if
roiSize
 has a field with zero or negative value.
ippStsStepErr
Indicates an error condition if
srcStep
,
dstStep
, or
srcDstStep
 has a zero or negative value.

Example

The code example below illustrates the use of left shift function.

IppStatus lshift( void ) {
   Ipp8u img[8*8] = { 1, 0x7F, 0xFE };
   IppiSize roi = { 8, 8 };
   IppStatus st = ippiLShiftC_8u_C1IR( 1, img, 8, roi );
   printf( "%02x %02x %02x\n", img[0], img[1], img[2] );
   return st;
}
Output values:
02 fe fc

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.