Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference

ID 790148
Date 3/22/2024
Public
Document Table of Contents

AlphaPremulC

Pre-multiplies pixel values of an image using constant alpha (opacity) values.

Syntax

Case 1: Not-in-place operation

IppStatus ippiAlphaPremulC_<mod>(const Ipp<datatype>* pSrc, int srcStep, Ipp<datatype> alpha, Ipp<datatype>* pDst, int dstStep, IppiSize roiSize);

Supported values for mod :

8u_C1R

16u_C1R

8u_C3R

16u_C3R

8u_C4R

16u_C4R

8u_AC4R

16u_AC4R

IppStatus ippiAlphaPremulC_<mod>(const Ipp<datatype>* const pSrc[4], int srcStep, Ipp<datatype> alpha, Ipp<datatype>* const pDst[4], int dstStep, IppiSize roiSize);

Supported values for mod :

8u_AP4R

16u_AP4R

Case 2: In-place operation

IppStatus ippiAlphaPremulC_<mod>(Ipp<datatype> alpha, Ipp<datatype>* pSrcDst, int srcDstStep, IppiSize roiSize);

Supported values for mod :

8u_C1IR

16u_C1IR

8u_C3IR

16u_C3IR

8u_C4IR

16u_C4IR

8u_AC4IR

16u_AC4IR

IppStatus ippiAlphaPremulC_<mod>(Ipp<datatype> alpha, 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 separate ROI in the 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 image ROI or an array of pointers to ROI in the 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.

alpha

Global alpha value used for pre-multiplying pixel values.

Description

This function operates with ROI (see Regions of Interest in Intel IPP).

This function converts either a one-, three-, four-channel image or planar RGBA image to the pre-multiplied alpha form, using the global alpha value alpha. For one-, three-, four-channel image buffers, pixel values in each channel are multiplied by α; for RGBA (pixel order and planar) images with (r,g,b,a) pixel values, new pixel values are (r*α, g*α, b*α, alpha) after execution of this function. Here α is the normalized alpha value in the range 0 to 1.

The function ippiAlphaPremulC 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.