RotateCenter

Syntax

Parameters

pSrc	Pointer to the source image origin. An array of separate pointers to each plane for data in planar format.
srcSize	Size in pixels of the source image.
srcStep	Distance in bytes between starts of consecutive lines in the source image buffer.
srcRoi	Region of interest in the source image (of the IppiRect type).
pDst	Pointer to the destination image origin. An array of separate pointers to each plane for data in planar format.
dstStep	Distance in bytes between starts of consecutive lines in the destination image buffer.
dstRoi	Region of interest in the destination image (of the IppiRect type).
angle	The angle of rotation in degrees.
xCenter, yCenter	Center of rotation coordinates.
interpolation	Specifies the interpolation mode. Possible values are:
	IPPI_INTER_NN - nearest neighbor interpolation
	IPPI_INTER_LINEAR - linear interpolation
	IPPI_INTER_CUBIC - cubic interpolation
	IPPI_INTER_CUBIC2P_CATMULLROM - Catmull-Rom spline
	the following flag is used additionally to the above modes:
	IPPI_SMOOTH_EDGE - edge smoothing

Description

The function ippiRotateCenter is declared in the ippi.h file. It operates with ROI (see ROI Processing in Geometric Transforms).

This function rotates the ROI of the source image by angle degrees (counterclockwise for positive angle values) around the point with coordinates xCenter, yCenter. The origin of the source image is implied to be in the top left corner. The result is resampled using the interpolation mode specified by the interpolation parameter, and written to the destination image ROI.

Example “Using the function ippiRotateCenter” shows how to use the function ippiRotateCenter_8u_C1R.

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 any image dimension has zero or negative value.
ippStsStepErr	Indicates an error condition if srcStep or dstStep has a zero or negative value.
ippStsInterpolationErr	Indicates an error condition if interpolation has an illegal value.
ippStsRectErr	Indicates an error condition if width or height of the intersection of the srcRoi and source image is less than or equal to 1.
ippStsWrongIntersectQuad	Indicates a warning that no operation is performed if the transformed source ROI has no intersection with the destination ROI.

Using the function ippiRotateCenter

IppiSize srcSize = { 4, 4 }, dstSize = { 6, 6 };

IppiRect srcRect = { 0, 0, 4, 4};

IppiRect dstRect = { 0, 0, 6, 6};

Ipp8u src[4*4] = {4, 4, 4, 4,

      3, 3, 3, 3,

      2, 2, 2, 2,

      1, 1, 1, 1};

Ipp8u dst[6*6];

double angle = -45.0;

double xCenter = 1.0;

double yCenter = 4.0;

ippiSet_8u_C1R ( 0, dst, 6, dstSize);

ippiRotateCenter_8u_C1R (src, srcSize, 4, srcRect, dst, 6, dstRect, angle,
                         xCenter, yCenter, IPPI_INTER_NN);

Result:

4 4 4 4

3 3 3 3

2 2 2 2    src

1 1 1 1

0 0 0 0 0 0

0 0 0 4 0 0

0 0 2 3 4 0

0 0 1 2 3 0    dst

0 0 0 1 0 0

0 0 0 0 0 0