Developer Reference

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

AlphaPremul

Pre-multiplies pixel values of an image by its alpha values.

Syntax

Case 1: Not-in-place operation
IppStatus ippiAlphaPremul_<mod>
(
const Ipp<datatype>*
pSrc
,
int
srcStep
,
Ipp<datatype>*
pDst
,
int
dstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_AC4R
16u_AC4R
IppStatus ippiAlphaPremul_<mod>
(
const Ipp<datatype>* const
pSrc
[4]
,
int
srcStep
,
Ipp<datatype>* const
pDst
[4]
,
int
dstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_AP4R
16u_AP4R
Case 2: In-place operation
IppStatus ippiAlphaPremul_<mod>
(
Ipp<datatype>*
pSrcDst
,
int
srcDstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_AC4IR
16u_AC4IR
IppStatus ippiAlphaPremul_<mod>
(
Ipp<datatype>* const
pSrcDst
[4]
,
int
srcDstStep
,
IppiSize
roiSize
);
Supported values for
mod
:
8u_AP4IR
16u_AP4IR
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 for pixel-order data. An array of pointers to ROI in the separate source color planes in case of planar data.
srcStep
Distance in bytes between starts of consecutive lines in the source image.
pDst
Pointer to the destination image ROI for pixel-order data. An array of pointers to ROI in the separate destination color planes in case of planar data.
dstStep
Distance in bytes between starts of consecutive lines in the destination image.
pSrcDst
Pointer to the source and destination buffer or an array of pointers to separate source and destination color planes 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 converts a RGBA source image (pixel order or planar) to the pre-multiplied alpha form. If (r,g,b,a) are the red, green, blue, and alpha values of a pixel, then new pixel values are (r*
α
, g*
α
, b*
α
, a) after execution of this function. Here
α
is the pixel normalized alpha value in the range 0 to 1.
The function
ippiAlphaPremul
can be used for unsigned pixel data only.
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.

Product and Performance Information

1

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