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### QUAD_TO_QUAD_PROJECTIVE_TRANSFORM

QUAD_TO_QUAD_PROJECTIVE_TRANSFORM

## Name

QUAD_TO_QUAD_PROJECTIVE_TRANSFORM

## Purpose

This function will perform a quadrilateral-to-quadrilateral projective
transform of the provided image. The transformation is defined using
the provided quadrilateral vertices defined in a clockwise order
beginning at the upper left-hand corner. The provided image coordinates
are targeted to fall at the provided map coordinates.

GENERAL.

## Calling Sequence

result = QUAD_TO_QUAD_PROJECTIVE_TRANSFORM( image, \$
imageQuad, \$
mapQuad, \$
MAP_DIMENSIONS=mapDimensions, \$
BACKGROUND_VALUE=backgroundValue

## Inputs

image
A two-dimensional or three-dimensional array containg either greyscale
or color image data, respectively.
imageQuad
An 8-element vector containing the vertices of the quadilateral enclosing
the region on the image to be transformed. The vector has the form
[ xUL, yUL, xUR, yUR, xLR, yLR, xLL, yLL ]
mapQuad
An 8-element vector containing the vertices of the quadilateral enclosing
the region on the map to be targeted. The vector has the form
[ uUL, vUL, uUR, vUR, uLR, vLR, uLL, vLL ]

## Keyword Parametrs

MAP_DIMENSIONS
Set this keyword to a 2-element vector containing the [width,height] of
the targeted map region. If this is omitted, a region corresponding to
the bounding rectangle around the quadrilateral vertices will be used.
BACKGROUND_VALUE
Set this keyword to the value to be placed in the transformed data
at points that fall outside the boundaries of the provided image to be
transformed [DEFAULT=0].
:ERROR CHECKING:
None.

None.

## Requires

NORMH
PROJECTIVE_MAPPING_MATRIX

## Modification History

Written by: Carl Salvaggio
January, 2012 Original code

## Disclaimer

This source code is provided "as is" and without warranties as to performance
or merchantability. The author and/or distributors of this source code may
have made statements about this source code. Any such statements do not
constitute warranties and shall not be relied on by the user in deciding
whether to use this source code.
This source code is provided without any express or implied warranties
whatsoever. Because of the diversity of conditions and hardware under which
this source code may be used, no warranty of fitness for a particular purpose
is offered. The user is advised to test the source code thoroughly before
relying on it. The user must assume the entire risk of using the source code.

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