transltform2d

2-D translation geometric transformation

Since R2022b

Description

A transltform2d object stores information about a 2-D translation geometric transformation and enables forward and inverse transformations.

Creation

Syntax

tform = transltform2d

tform = transltform2d(Translation)

tform = transltform2d(tx,ty)

tform = transltform2d(A)

tform = transltform2d(tformIn)

Description

tform = transltform2d creates a transltform2d object that performs the identity transformation.

tform = transltform2d(Translation) creates a transltform2d object that performs a translation transformation based on the specified value of the Translation property. This property specifies the amount of translation in the x- and y-directions.

tform = transltform2d(tx,ty) creates a transltform2d object that performs a translation transformation with the specified amounts of translation tx and ty in the x- and y-directions, respectively.

tform = transltform2d(A) creates a transltform2d object and sets the property A as the specified 2-D translation transformation matrix.

tform = transltform2d(tformIn) creates a transltform2d object from another geometric transformation object, tformIn, that represents a valid 2-D translation geometric transformation.

Input Arguments

tx — Amount of translation in x-direction

numeric scalar

Amount of translation in the x-direction, specified as a numeric scalar. This value sets the first element of the Translation property.

ty — Amount of translation in y-direction

numeric scalar

Amount of translation in the y-direction, specified as a numeric scalar. This value sets the second element of the Translation property

tformIn — Translation 2-D geometric transformation

affinetform2d object | rigidtform2d object | simtform2d object | transltform2d object | projtform2d object

Translation 2-D geometric transformation, specified as an affinetform2d object, rigidtform2d object, simtform2d object, transltform2d object, or projtform2d object.

Properties

A — Forward 2-D translation transformation

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

Forward 2-D translation transformation, specified as a 3-by-3 numeric matrix. When you create the object, you can also specify A as a 2-by-3 numeric matrix. In this case, the object concatenates the row vector [0 0 1] to the end of the matrix, forming a 3-by-3 matrix. The default of A is the identity matrix.

The matrix A transforms the point (u, v) in the input coordinate space to the point (x, y) in the output coordinate space using the convention:

$$\left[\begin{array}{c}x\\ y\\ 1\end{array}\right]={\rm A}\times \left[\begin{array}{c}u\\ v\\ 1\end{array}\right]$$

For a translation transformation, A has the form:

$${\rm A}=\left[\begin{array}{ccc}1& 0& t_x\\ 0& 1& t_y\\ 0& 0& 1\end{array}\right]$$

where t_x and t_y are the amount of translation in the x- and y-directions, respectively, and correspond to the Translation property.

Data Types: double | single

Translation — Amount of translation

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

Amount of translation, specified as a 2-element numeric vector of the form [t_x t_y].

Data Types: double | single

Dimensionality — Dimensionality of geometric transformation

2 (default)

This property is read-only.

Dimensionality of the geometric transformation for both input and output points, specified as 2.

Data Types: double

Object Functions

invert	Invert geometric transformation
outputLimits	Find output spatial limits given input spatial limits
transformPointsForward	Apply forward geometric transformation
transformPointsInverse	Apply inverse geometric transformation

Examples

Create 2-D Translation Transformation

Specify the amount of translation.

t = [10 20.5];

Create a transltform2d object that performs the specified translation.

tform = transltform2d(t)

tform = 
  transltform2d with properties:

    Dimensionality: 2
       Translation: [10 20.5000]

                 A: [1.0000         0   10.0000
                          0    1.0000   20.5000
                          0         0    1.0000]

Examine the value of the A property.

tform.A

ans = 3×3

    1.0000         0   10.0000
         0    1.0000   20.5000
         0         0    1.0000

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• transltform2d supports the generation of C code (requires MATLAB^® Coder™). For more information, see Code Generation for Image Processing.

• When generating code, you can only specify singular objects. Arrays of objects are not supported.

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Version History

Introduced in R2022b