Developer Reference

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

RGBToYUV420

Converts an RGB image to the 4:2:0 YUV image.

Syntax

Case 1: Operation on planar data with ROI
IppStatus ippiRGBToYUV420_8u_P3R(const Ipp8u*
pSrc
[3], int
srcStep
, Ipp8u*
pDst
[3], int
dstStep
[3], IppiSize
roiSize
);
Case 2: Operation on planar data without ROI
IppStatus ippiRGBToYUV420_8u_P3(const Ipp8u*
pSrc
[3], Ipp8u*
pDst
[3], IppiSize
imgSize
);
Case 3: Conversion from pixel-order to planar data with ROI
IppStatus ippiRGBToYUV420_8u_C3P3R(const Ipp8u*
pSrc
, int
srcStep
, Ipp8u*
pDst
[3], int
dstStep
[3], IppiSize
roiSize
);
Case 4: Conversion from pixel-order to planar data without ROI
IppStatus ippiRGBToYUV420_8u_C3P3(const Ipp8u*
pSrc
, Ipp8u*
pDst
[3], IppiSize
imgSize
);
Include Files
ippcc.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
,
ipps.h
,
ippi.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
,
ippi.lib
Parameters
pSrc
Pointer to the source image buffer for pixel-order image. An array of pointers to the source image buffers in each color plane for planar image.
srcStep
Distance in bytes between starts of consecutive lines in the source image for operations with ROI.
pDst
An array of pointers to the destination image buffers in each color plane.
dstStep
An array of distances in bytes between starts of consecutive lines in each plane of the destination image for operations with ROI.
roiSize
Size of the source and destination ROI in pixels.
imgSize
Size of the source and destination images in pixels for operations without ROI.
Description
This function converts the gamma-corrected
R'G'B'
image
pSrc
to the
Y'U'V'
image
pDst
with the
4:2:0 sampling
(see Table
“Planar Image Formats”
for more details). The conversion is performed in the accordance with the same formulas as the function
ippiRGBToYUV
does.
For digital RGB values in the range [0..255],
Y'
has the range [0..255],
U
varies in the range [-112..+112], and
V
in the range [-157..+157]. To fit in the range of [0..255], a constant value 128 is added to computed
U
and
V
values, and
V
is then saturated.
Some function flavors operates with ROI see Regions of Interest in Intel IPP).
The function flavors that does not use ROI operate on the assumption that both the source and destination images have the same size and occupy a contiguous memory area, which means that image rows are not padded with zeroes. In this case the step parameters are not needed.
roiSize.width
(
imgSize.width
) and
roiSize.height
(
imgSize.height
) should be multiples of 2. Otherwise, the function reduces their original values to the nearest multiples of 2, performs operation, and returns warning message.
Return Values
ippStsNoErr
Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr
Indicates an error condition if
pSrc
or
pDst
is
NULL
.
ippStsSizeErr
Indicates an error condition if
roiSize
or
imgSize
has a field with a zero or negative value.
ippStsDoubleSize
Indicates a warning if
roiSize
or
imgSize
has a field that is not a multiple of 2.

Product and Performance Information

1

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