rigid2d

2-D rigid geometric transformation

Description

A rigid2d object stores information about a 2-D rigid geometric transformation and enables forward and inverse transformations.

Creation

Syntax

tform = rigid2d

tform = rigid2d(t)

tform = rigid2d(rot,trans)

Description

tform = rigid2d creates a default rigid2d object that corresponds to an identity transformation.

tform = rigid2d(t) creates a rigid2d object based on a specified forward rigid transformation matrix, t. The t input sets the T property.

tform = rigid2d(rot,trans) creates a rigid2d object based on the rotation, rot, and translation, trans, components of the transformation. rot sets the Rotation property. trans sets the Translation property.

Properties

T — Forward rigid transformation

3-by-3 identity matrix (default) | 3-by-3 numeric matrix

Forward rigid transformation, specified as a 3-by-3 numeric matrix.

Data Types: single | double

Dimensionality — Dimensionality of geometric transformation

2 (default)

This property is read-only.

Dimensionality of the geometric transformation, specified as the number 2.

Rotation — Rotation component of transformation

2-by-2 identity matrix (default) | 2-by-2 numeric matrix

Rotation component of the transformation, specified as a 2-by-2 numeric matrix.

Data Types: single | double

Translation — Translation component of transformation

[0 0] (default) | 2-element numeric row vector

Translation component of the transformation, specified as a 2-element numeric row vector.

Data Types: single | double

Object Functions

invert	Invert geometric transformation
isTranslation	Determine if transformation is pure translation
outputLimits	Find output spatial limits given input spatial limits
transformPointsForward	Apply forward geometric transformation
transformPointsInverse	Apply inverse geometric transformation

Examples

Create Rigid 2-D Object with Defined Translation and Rotation

Specify an angle of rotation in degrees and create a 2-by-2 rotation matrix.

theta = 30;
rot = [ cosd(theta) sind(theta); ...
       -sind(theta) cosd(theta)];

Specify the amount of horizontal and vertical translation, respectively.

trans = [2 3];

Create a rigid2d object that performs the rotation and translation.

tform = rigid2d(rot,trans)

tform = 
  rigid2d with properties:

       Rotation: [2x2 double]
    Translation: [2 3]