Perspective Warp

Perspective Warp. More...

Macros
#define	VPI_WARP_INVERSE   (1u)
	Flag to inform that the matrix used in warp operation is already inverted. More...

Typedefs
typedef float	VPIPerspectiveTransform[3][3]
	Represents a 2D perspective transform. More...

Functions
VPIStatus	vpiCreatePerspectiveWarp (VPIBackend backend, VPIPayload *payload)
	Creates a payload for Perspective Warp algorithm. More...
VPIStatus	vpiSubmitPerspectiveWarp (VPIStream stream, VPIPayload payload, VPIImage input, const VPIPerspectiveTransform xform, VPIImage output, VPIInterpolationType interp, VPIBoundaryCond bcond, uint32_t flags)
	Submits the Perspective Warp operation to the stream associated with the payload. More...

Detailed Description

Perspective Warp.

Macro Definition Documentation

VPI_WARP_INVERSE

#define VPI_WARP_INVERSE   (1u)

#include <vpi/algo/PerspectiveWarp.h>

Flag to inform that the matrix used in warp operation is already inverted.

If user has the transform matrix already inverted, setting this flag allows the warp operation to use it directly instead of inverting it itself prior processing. This is particularly useful if matrix inversion would result in large numerical errors, such as when its determinant is close to zero.

Definition at line 90 of file PerspectiveWarp.h.

Typedef Documentation

VPIPerspectiveTransform

typedef float VPIPerspectiveTransform[3][3]

#include <vpi/Types.h>

Represents a 2D perspective transform.

[vx]   [a11 a12 tx] [ux]
[vy] = [a21 a22 ty] [uy]
[vw]   [ p0  p1  p] [ 1]
u'x  = vx/vw
u'y  = vy/vw

In these equations,

• ux, uy are the inhomogeneous coordinates in the source image.
• u'x, u'y are the inhomogeneous coordinates in the destination image.
• vx,vy,vw are the homogeneous coordinates in the destination image.
• a11,a12,a21,a22 are the2x2 non-singular matrix with the linear component of the transform.
• tx,ty is the translation component of the transform.
• p0,p1,p are the projective components of the transform. p is usually 1.

Definition at line 512 of file Types.h.

Function Documentation

vpiCreatePerspectiveWarp()

VPIStatus vpiCreatePerspectiveWarp	(	VPIBackend	backend,
		VPIPayload *	payload
	)

#include <vpi/algo/PerspectiveWarp.h>

Creates a payload for Perspective Warp algorithm.

This function allocates all resources needed by the algorithm and ties the returned payload to the given stream.

Parameters

[in]	backend	VPI backend which the algorithm will be used.
[out]	payload	Pointer to a payload handle with the created payload.

Returns

VPI_SUCCESS if payload was created successfully, or some other VPIStatus value in case of error.

vpiSubmitPerspectiveWarp()

VPIStatus vpiSubmitPerspectiveWarp	(	VPIStream	stream,
		VPIPayload	payload,
		VPIImage	input,
		const VPIPerspectiveTransform	xform,
		VPIImage	output,
		VPIInterpolationType	interp,
		VPIBoundaryCond	bcond,
		uint32_t	flags
	)

#include <vpi/algo/PerspectiveWarp.h>

Submits the Perspective Warp operation to the stream associated with the payload.

Parameters

[in]	stream	The stream where the operation will be queued in.
[in]	payload	Payload created by vpiCreatePerspectiveWarp.
[in]	input	Input image to be warped.
[in]	xform	Transform to be applied.
[out]	output	Output image where warped image is written to.
[in]	interp	Interpolation mode to be used. Valid values: VPI_INTERP_NEAREST VPI_INTERP_LINEAR VPI_INTERP_CATMULL_ROM
[in]	bcond	Boundary condition to use for samples that fall outsize input's bounds. Value values: VPI_BOUNDARY_COND_ZERO
[in]	flags	Flags to modify algorithm behavior. Valid values: 0: default, transform isn't inverted, algorithm shall invert it. VPI_WARP_INVERSE : transform is already inverted, algorithm can use it directly.

Returns

VPI_SUCCESS if algorithm was submitted successfully, or some other VPIStatus value in case of error. Some errors will only be reported asynchronously by synchronization functions or subsequent algorithm submissions.