Visible to Intel only — GUID: GUID-98579DDF-CDEE-4C4A-B503-479E107058C3
Visible to Intel only — GUID: GUID-98579DDF-CDEE-4C4A-B503-479E107058C3
WarpAffineLinear
Performs warp affine transformation of an image using the linear interpolation method.
Syntax
IppStatus ippiWarpAffineLinear_<mod>(const Ipp<datatype>* pSrc, int srcStep, Ipp<datatype>* pDst, int dstStep, IppiPoint dstRoiOffset, IppiSize dstRoiSize, const IppiWarpSpec* pSpec, Ipp8u* pBuffer);
Supported values for mod:
8u_C1R |
16u_C1R |
16s_C1R |
32f_C1R |
64f_C1R |
8u_C3R |
16u_C3R |
16s_C3R |
32f_C3R |
64f_C3R |
8u_C4R |
16u_C4R |
16s_C4R |
32f_C4R |
64f_C4R |
Include Files
ippi.h
Flavors with the _L suffix: ippi_l.h
Domain Dependencies
Headers: ippcore.h, ippvm.h, ipps.h
Libraries: ippcore.lib, ippvm.lib, ipps.lib
Parameters
pSrc |
Pointer to the source image. |
srcStep |
Distance, in bytes, between the starting points of consecutive lines in the source image buffer. |
pDst |
Pointer to the destination image ROI. |
dstStep |
Distance, in bytes, between the starting points of consecutive lines in the destination image buffer. |
dstRoiOffset |
Offset of the destination image ROI with respect to the destination image origin. |
dstRoiSize |
Size of the destination image ROI, in pixels. |
pSpec |
Pointer to the specification structure for the warp operation. |
pBuffer |
Pointer to the work buffer. |
Description
This function transforms the source image pixel coordinates (x, y) according to the following formulas:
x' = c00*x + c01*y + c02
y' = c10*x + c11*y + c12
where
x' and y' are the pixel coordinates in the transformed image
cij are the affine transform coefficients passed to the coeffs array during initialization
The affine warping is a general linear transform that incorporates such elementary transformations as scaling, rotation, translation, stretching, and shearing. It always transforms parallel lines into parallel lines and preserves equal distances between points on a line.
The WarpAffineLinear function operates with ROI. The transformed part of the image is resampled with the linear interpolation method and stored in the destination image ROI. You need to define the destination image ROI origin by the following parameters: the offset of the destination ROI with respect to the destination image origin and the destination image ROI size. The parameter pSrc must point to the source image origin. The parameter pDst must point to the processed destination image ROI.
If you initialize the specification structure using the ippiWarpQuadLinearInit function, the operations take place only inside the specified source quadrangle srcQuad that is set in ippiWarpQuadLinearInit.
To specify the algorithm for borders processing, set the borderType and pBorderValue parameters when initializing the IppiWarpSpec structure. The data type of pBorderValue is automatically converted from Ipp64f to the data type of the processed images. The function supports the following algorithms for borders processing:
If the border type is equal to ippBorderRepl, the source image outer pixels are replicated from the edge pixels.
If the border type is equal to ippBorderConst, the outer pixels are set to the constant value specified in pBorderValue.
If the border type is equal to ippBorderTransp or ippBorderInMem, destination image pixels mapped to the outer source image pixels are not changed.
Before using the ippiWarpAffineLinear function, you need to initialize the IppiWarpSpec structure using the ippiWarpAffineLinearInit function and compute the size of the external buffer pBuffer using the WarpGetBufferSize function.
To compute the affine transform parameters, use the GetAffineQuad, GetAffineBound, and GetAffineTransform functions.
For an example on how to use this function, refer to the WarpQuadNearestInit function description.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when one of the specified pointers is NULL. |
ippStsNoOperation |
Indicates a warning when width or height of the destination image is equal to zero. |
ippStsBorderErr |
Indicates an error if border type has an illegal value. |
ippStsContextMatchErr |
Indicates an error when context data is invalid. |
ippStsNotSupportedModeErr |
Indicates an error when the requested mode is not supported. |
ippStsSizeErr |
Indicates an error when width or height of the source or destination image ROI is negative. |
ippStsStepErr |
Indicates an error when the step value is not a multiple of data type. |
ippStsOutOfRangeErr |
Indicates an error when the destination image offset point is outside the destination image origin. |
ippStsSizeWrn |
Indicates a warning when the destination image ROI size is more than the destination image origin size. |
ippStsWrongIntersectQuad |
Indicates a warning that no operation is performed if the destination ROI has no intersection with the transformed source image origin. |