## Developer Reference

• 2021
• 06/28/2021
• Public Content
Contents

# TiltedRectStdDev

Computes the standard deviation of the tilted integral images.

## Syntax

Include Files
ippcv.h
Domain Dependencies
ippcore.h
,
ippvm.h
,
ipps.h
,
ippi.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
,
ippi.lib
Parameters
pSrc
Pointer to the ROI in the source integral image.
srcStep
Distance in bytes between starts of consecutive lines in the source integral image.
pSqr
Pointer to the ROI in the source integral image of pixel squares.
sqrStep
Distance in bytes between starts of consecutive lines in the source integral image of pixel squares.
pDst
Pointer to the destination image ROI.
dstStep
Distance in bytes between starts of consecutive lines in the destination image.
roiSize
Size of destination image ROI in pixels.
rect
Rectangular window.
scaleFactor
Scale factor (see Integer Result Scaling).
Description
This function operates with ROI (see Regions of Interest in Intel IPP). This function computes the standard deviation for each pixel in the rectangular window
rect
using the tilted integral image
pSrc
and tilted integral image of pixel squares
pSqr
. The computations are performed in accordance with the following formulas:
where
i
,
j
are coordinates of the destination image pixels varying in the range
i
= 0 ,...,
roiSize.height
- 1,
j
= 0,...,
roiSize.width
- 1;
sum
=
pSrc
[
i
+
rect.x
-
rect.y
+
rect.height
+
rect.width
,
j
+
rect.x
+
rect.y
-
rect.height
+
rect.width
] -
pSrc
[
i
+
rect.x
-
rect.y
+
rect.width
,
j
+
rect.x
+
rect.y
+
rect.width
] -
pSrc
[
i
+
rect.x
-
rect.y
+
rect.height
,
j
+
rect.x
-
rect.y
-
rect.height
] +
pSrc
[
i
+
rect.x
-
rect.y
,
j
+
rect.x
+
rect.y
];
sumSqr
=
pSqr
[
i
+
rect.x
-
rect.y
+
rect.height
+
rect.width
,
j
+
rect.x
+
rect.y
-
rect.height
+
rect.width
] -
pSqr
[
i
+
rect.x
-
rect.y
+
rect.width
,
j
+
rect.x
+
rect.y
+
rect.width
] -
pSqr
[
i
+
rect.x
-
rect.y
+
rect.height
,
j
+
rect.x
-
rect.y
-
rect.height
] +
pSqr
[
i
+
rect.x
-
rect.y
,
j
+
rect.x
+
rect.y
];
numPix
= 2 *
rect.height
*
rect.width
.
The minimum size of each source images
pSrc
and
pSqr
should be (
roiSize.width
+
rect.height
+
rect.width - 2
) x (
roiSize.height
+
rect.x
+
rect.y
+
rect.height
+
rect.width - 2
).
The source images
pSrc
and
pSqr
can be obtained by using the functions ippiTiltedIntegral or ippiTiltedSqrIntegral.
Return Values
ippStsNoErr
Indicates no error.
ippStsNullPtrErr
Indicates an error if one of the specified pointers is
NULL
.
ippStsSizeErr
Indicates an error condition if
roiSize
has a field with zero or negative value.
ippStsSizeErr
Indicates an error condition if
rect.width
or
rect.height
is less than or equal to zero, or if
rect.x
or
rect.y
is less than zero.
ippStsStepErr
Indicates an error condition if
srcStep
or
sqrStep
is less than
(roiSize.width+rect.x+rect.width+1) * <pixelSize>
, or
dstStep
is less than
roiSize.width * <pixelSize>
.
ippStsNotEvenStepErr
Indicates an error condition if
sqrStep
is not divisible by 8, or one of
pSrc
and
dstStep
is not divisible by 4.

#### Product and Performance Information

1

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