Affine Warp

Functions for Affine Warp of images. More...

Enumerations
enum	SimdWarpAffineFlags {   SimdWarpAffineDefault = 0 ,   SimdWarpAffineChannelByte = 0 ,   SimdWarpAffineChannelMask = 1 ,   SimdWarpAffineInterpNearest = 0 ,   SimdWarpAffineInterpBilinear = 2 ,   SimdWarpAffineInterpMask = 2 ,   SimdWarpAffineBorderConstant = 0 ,   SimdWarpAffineBorderTransparent = 4 ,   SimdWarpAffineBorderMask = 4 }

Functions
SIMD_API void *	SimdWarpAffineInit (size_t srcW, size_t srcH, size_t srcS, size_t dstW, size_t dstH, size_t dstS, size_t channels, const float *mat, SimdWarpAffineFlags flags, const uint8_t *border)
	Creates wrap affine context. More...
SIMD_API void	SimdWarpAffineRun (const void *context, const uint8_t *src, uint8_t *dst)
	Performs warp affine for current image. More...
template<template< class > class A>
SIMD_INLINE void	WarpAffine (const View< A > &src, const float *mat, View< A > &dst, SimdWarpAffineFlags flags=(SimdWarpAffineFlags)(SimdWarpAffineChannelByte|SimdWarpAffineInterpBilinear|SimdWarpAffineBorderConstant), const uint8_t *border=NULL)
	Performs warp affine for current image. More...
SIMD_INLINE bool	InvertAffineTransform (const float *src, float *dst)
	Performs inversion of warp affine transform matrix. More...

Detailed Description

Functions for Affine Warp of images.

Enumeration Type Documentation

SimdWarpAffineFlags

enum SimdWarpAffineFlags

Describes Warp Affine flags. This type used in function SimdWarpAffineInit.

Enumerator
SimdWarpAffineDefault	Default Warp Affine flags.
SimdWarpAffineChannelByte	8-bit integer channel type.
SimdWarpAffineChannelMask	Bit mask of channel type.
SimdWarpAffineInterpNearest	Nearest pixel interpolation method.
SimdWarpAffineInterpBilinear	Bilinear pixel interpolation method.
SimdWarpAffineInterpMask	Bit mask of pixel interpolation options.
SimdWarpAffineBorderConstant	Nearest pixel interpolation method.
SimdWarpAffineBorderTransparent	Bilinear pixel interpolation method.
SimdWarpAffineBorderMask	Bit mask of pixel interpolation options.

Function Documentation

SimdWarpAffineInit()

void * SimdWarpAffineInit	(	size_t	srcW,
		size_t	srcH,
		size_t	srcS,
		size_t	dstW,
		size_t	dstH,
		size_t	dstS,
		size_t	channels,
		const float *	mat,
		SimdWarpAffineFlags	flags,
		const uint8_t *	border
	)

Creates wrap affine context.

Simplified, then warp affine performs next transformation for every pixel:

dst[x, y] = src[x * mat[0][0] + y * mat[0][1] + mat[0][2], x * mat[1][0] + y * mat[1][1] + mat[1][2]];

An using example (for BGR image):

float mat[2][3] = { { 1.0f, -1.0f, 0.0f }, { 1.0f, 1.0f, 0.0f } };
SimdWarpAffineFlags flags = SimdWarpAffineChannelByte | SimdWarpAffineInterpBilinear | SimdWarpAffineBorderConstant;
void* context = SimdWarpAffineInit(srcW, srcH, srcS, dstW, dstH, dstS, 3, mat, flags, NULL);
if (context)
{
     SimdWarpAffineRun(context, src, dst);
     SimdRelease(context);
}

Note

This function has a C++ wrapper Simd::WarpAffine(const View& src, const float * mat, View& dst, SimdWarpAffineFlags flags = SimdWarpAffineInterpBilinear | SimdWarpAffineBorderConstant, const uint8_t* border = NULL).

Parameters

[in]	srcW	- a width of input image.
[in]	srcH	- a height of input image.
[in]	srcS	- a row size (in bytes) of the input image.
[in]	dstW	- a width of output image.
[in]	dstH	- a height of output image.
[in]	dstS	- a row size (in bytes) of the output image.
[in]	channels	- a channel number of input and output image. Its value must be in range [1..4].
[in]	mat	- a pointer to 2x3 matrix with coefficients of affine warp.
[in]	flags	- a flags of algorithm parameters.
[in]	border	- a pointer to to the array with color of border. The size of the array must be equal to channels. It parameter is actual for SimdWarpAffineBorderConstant flag. It can be NULL.

Returns

a pointer to warp affine context. On error it returns NULL. This pointer is used in functions SimdWarpAffineRun. It must be released with using of function SimdRelease.

SimdWarpAffineRun()

void SimdWarpAffineRun	(	const void *	context,
		const uint8_t *	src,
		uint8_t *	dst
	)

Performs warp affine for current image.

Note

This function has a C++ wrapper Simd::WarpAffine(const View& src, const float * mat, View& dst, SimdWarpAffineFlags flags = SimdWarpAffineInterpBilinear | SimdWarpAffineBorderConstant, const uint8_t* border = NULL).

Parameters

[in]	context	- a warp affine context. It must be created by function SimdWarpAffineInit and released by function SimdRelease.
[in]	src	- a pointer to pixels data of the original input image.
[out]	dst	- a pointer to pixels data of the filtered output image.

WarpAffine()

void WarpAffine	(	const View< A > &	src,
		const float *	mat,
		View< A > &	dst,
		SimdWarpAffineFlags	flags = (SimdWarpAffineFlags)(SimdWarpAffineChannelByte | SimdWarpAffineInterpBilinear | SimdWarpAffineBorderConstant),
		const uint8_t *	border = NULL
	)

Performs warp affine for current image.

Note

This function is a C++ wrapper for functions SimdWarpAffineInit and SimdWarpAffineRun.

Parameters

[in]	src	- an input image.
[in]	mat	- a pointer to 2x3 matrix with coefficients of affine warp.
[in,out]	dst	- an output image.
[in]	flags	- a flags of algorithm parameters. By default is equal to SimdWarpAffineChannelByte | SimdWarpAffineInterpBilinear | SimdWarpAffineBorderConstant.
[in]	border	- a pointer to to the array with color of border. The size of the array must be equal to channels. It parameter is actual for SimdWarpAffineBorderConstant flag. By default is equal to NULL.

InvertAffineTransform()

bool InvertAffineTransform	(	const float *	src,
		float *	dst
	)

Performs inversion of warp affine transform matrix.

Note

This function is a C++ wrapper for functions SimdWarpAffineInit and SimdWarpAffineRun.

Parameters

[in]	src	- a pointer to input 2x3 matrix with coefficients of affine warp.
[out]	dst	- a pointer to output 2x3 matrix with coefficients of inverse affine warp.

Returns

false if can't inverse it.