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transformPointsInverse

Class: projective2d

Apply inverse 2-D geometric transformation to points

Syntax

[u,v] = transformPointsInverse(tform,x,y)
U = transformPointsInverse(tform,X)

Description

[u,v] = transformPointsInverse(tform,x,y) applies the inverse transformation of tform to the input 2-D point arrays x and y and outputs the point arrays u and v. The input point arrays x and y must be of the same size.

U = transformPointsInverse(tform,X) applies the inverse transformation of tform to the input n-by-2 point matrix X and outputs the n-by-2 point matrix U. transformPointsFoward maps the point X(k,:) to the point U(k,:).

Input Arguments

tform

Geometric transformation, specified as an projective2d geometric transformation object.

x

Coordinates in X dimension of points to be transformed, specified as a array.

y

Coordinates in Y dimension of points to be transformed, specified as a array.

X

X and Y coordinates of points to be transformed, specified as an n-by-2 matrix

Output Arguments

u

Transformed coordinates in X dimension, returned as an array.

v

Transformed coordinates in Y dimension, returned as an array.

U

Transformed X and Y coordinates, returned as an n-by-2 matrix

Examples

expand all

Create an projective2d object that defines the transformation.

theta = 10;
tform = projective2d([cosd(theta) -sind(theta) 0.001; sind(theta) cosd(theta) 0.01; 0 0 1])
tform = 

  projective2d with properties:

                 T: [3x3 double]
    Dimensionality: 2

Apply forward geometric transformation to an input point.

[X,Y] = transformPointsForward(tform,5,10)
X =

    6.0276


Y =

    8.1265

Apply inverse geometric transformation to output point from the previous step to recover the original coordinates.

[U,V] = transformPointsInverse(tform,X,Y)
U =

    5.0000


V =

    10
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