isTranslation

Determine if geometric transformation is pure translation

Syntax

TF = isTranslation(tform)

Description

TF = isTranslation(tform) determines whether or not the rigid or affine transformation specified by tform is a pure translation.

Examples

Check If 2-D Transformation Is a Pure Translation

Create an affine2d object that defines a pure translation.

A = [ 1  0  0
      0  1  0
     40 40  1 ];

tform = affine2d(A)

tform = 

  affine2d with properties:

                 T: [3x3 double]
    Dimensionality: 2

Check if the transformation is a pure translation.

tf = isTranslation(tform)

tf =

     1

Check If 3-D Transformation Is a Pure Translation

Create an affine3d object that defines a different scale factor in each dimension.

Sx = 1.2;
Sy = 1.6;
Sz = 2.4;
tform = affine3d([Sx 0 0 0; 0 Sy 0 0; 0 0 Sz 0; 0 0 0 1]);

tf = 

  affine3d with properties:

                 T: [4x4 double]
    Dimensionality: 3

Check if the transformation is a pure translation. Since tform scales the object,

tf = isTranslation(tform)

tf =

     0

As expected, the transformation is not a pure translation since scaling changes the size and shape of an input volume.

Input Arguments

tform — Geometric transformation

affine2d object | affine3d object | rigid2d object

Geometric transformation, specified as an affine2d, affine3d, or rigid2d geometric transformation object.

Output Arguments

TF — Geometric transformation is pure translation

true | false

Geometric transformation is pure translation, returned as true or false.

Data Types: logical

More About

Translation Transformation

A translation transformation shifts an image without modifying the image size, shape, or orientation. A 2-D translation is represented by a matrix T of the form:

 [1 0 0;
  0 1 0;
  e f 1];

A 3-D translation is represented by a matrix of the form:

 [1 0 0 0;
  0 1 0 0;
  0 0 1 0;
  j k l 1];

Version History

Introduced in R2013a