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, orsrcDstStep 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
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