randomAffine2d
Create randomized 2-D affine transformation
Description
specifies the type of affine transformations using name-value pair arguments.tform
= randomAffine2d(Name,Value
)
Examples
Randomly Rotate Image
Read and display an image.
I = imread('kobi.png');
imshow(I)
Create an affine2d
transformation object that rotates images. The randomAffine2d
function picks a rotation angle randomly from a continuous uniform distribution within the interval [35, 55] degrees.
tform1 = randomAffine2d('Rotation',[35 55]);
Rotate the image and display the result.
J = imwarp(I,tform1); imshow(J)
The transformation object, tform1
, rotates all images by the same amount. To rotate an image by a different randomly selected amount, create a new affine2d
transformation object.
tform2 = randomAffine2d('Rotation',[-10 10]);
J2 = imwarp(I,tform2);
imshow(J2)
Randomly Rotate Image with Custom Rotation Range
Read and display an image.
I = imread('sherlock.jpg');
imshow(I)
Create an affine2d
transformation object that rotates images. To select a rotation angle from a custom range, specify the 'Rotation'
name-value pair argument as a function handle. This example specifies a function called myrange
(defined at the end of the example) that selects an angle from within two disjoint intervals.
tform = randomAffine2d('Rotation',@myrange);
Rotate the image and display the result.
J = imwarp(I,tform); imshow(J)
Supporting Function
This example defines the myrange
function that first randomly selects one of two intervals (-10, 10) and (170, 190) with equal probability. Within the selected interval, the function returns a single random number from a uniform distribution.
function angle = myrange() if randi([0 1],1) a = -10; b = 10; else a = 170; b = 190; end angle = a + (b-a).*rand(1); end
Input Arguments
Name-Value Arguments
Specify optional pairs of arguments as
Name1=Value1,...,NameN=ValueN
, where Name
is
the argument name and Value
is the corresponding value.
Name-value arguments must appear after other arguments, but the order of the
pairs does not matter.
Before R2021a, use commas to separate each name and value, and enclose
Name
in quotes.
Example: tform = randomAffine2d('XReflection',true)
XReflection
— Random horizontal reflection
false
(default) | true
Random horizontal reflection, specified as the comma-separated pair consisting of
'XReflection'
and false
or
true
. When XReflection
is
true
(1
), the transformation
tform
reflects images horizontally with 50% probability. By
default, the transformation does not reflect images in the horizontal
direction.
YReflection
— Random vertical reflection
false
(default) | true
Random vertical reflection, specified as the comma-separated pair consisting of
'YReflection'
and false
or
true
. When YReflection
is
true
(1
), the transformation
tform
reflects images vertically with 50% probability. By
default, the transformation does not reflect images in the vertical direction.
Rotation
— Range of rotation
[0 0]
(default) | 2-element numeric vector | function handle
Range of rotation, in degrees, applied to the input image, specified as the
comma-separated pair consisting of 'Rotation'
and one of the following.
2-element numeric vector. The second element must be larger than or equal to the first element. The rotation angle is picked randomly from a continuous uniform distribution within the specified interval.
function handle. The function must accept no input arguments and return the rotation angle as a numeric scalar. Use a function handle to pick rotation angles from a disjoint interval or using a nonuniform probability distribution. For more information about function handles, see Create Function Handle.
By default, the transformation tform
does not rotate
images.
Example: [-45 45]
Scale
— Range of uniform scaling
[1 1]
(default) | 2-element numeric vector | function handle
Range of uniform (isotropic) scaling applied to the input image, specified as the
comma-separated pair consisting of 'Scale'
and one of the following.
2-element numeric vector. The second element must be larger than or equal to the first element. The scale factor is picked randomly from a continuous uniform distribution within the specified interval.
function handle. The function must accept no input arguments and return the scale factor as a numeric scalar. Use a function handle to pick scale factors from a disjoint interval or using a nonuniform probability distribution. For more information about function handles, see Create Function Handle.
By default, the transformation tform
does not scale
images.
Example: [0.5 4]
XShear
— Range of horizontal shear
[0 0]
(default) | 2-element numeric vector | function handle
Range of horizontal shear applied to the input image, specified as the
comma-separated pair consisting of 'XShear'
and one of the
following. Shear is measured as an angle in degrees, and is in the range (–90, 90).
2-element numeric vector. The second element must be larger than or equal to the first element. The horizontal shear angle is picked randomly from a continuous uniform distribution within the specified interval.
function handle. The function must accept no input arguments and return the horizontal shear angle as a numeric scalar. Use a function handle to pick horizontal shear angles from a disjoint interval or using a nonuniform probability distribution. For more information about function handles, see Create Function Handle.
By default, the transformation tform
does not shear images in
the horizontal direction.
Example: [0 45]
YShear
— Range of vertical shear
[0 0]
(default) | 2-element numeric vector | function handle
Range of vertical shear applied to the input image, specified as the
comma-separated pair consisting of 'YShear'
and one of the
following. Shear is measured as an angle in degrees, and is in the range (–90, 90).
2-element numeric vector. The second element must be larger than or equal to the first element. The vertical shear angle is picked randomly from a continuous uniform distribution within the specified interval.
function handle. The function must accept no input arguments and return the vertical shear angle as a numeric scalar. Use a function handle to pick vertical shear angles from a disjoint interval or using a nonuniform probability distribution. For more information about function handles, see Create Function Handle.
By default, the transformation tform
does not shear images in
the vertical direction.
Example: [0 45]
XTranslation
— Range of horizontal translation
[0 0]
(default) | 2-element numeric vector | function handle
Range of horizontal translation applied to the input image, specified as the
comma-separated pair consisting of 'XTranslation'
and one of the
following. Translation distance is measured in pixels.
2-element numeric vector. The second element must be larger than or equal to the first element. The horizontal translation distance is picked randomly from a continuous uniform distribution within the specified interval.
function handle. The function must accept no input arguments and return the horizontal translation distance as a numeric scalar. Use a function handle to pick horizontal translation distances from a disjoint interval or using a nonuniform probability distribution. For more information about function handles, see Create Function Handle.
By default, the transformation tform
does not translate
images in the horizontal direction.
Example: [-5 5]
YTranslation
— Range of vertical translation
[0 0]
(default) | 2-element numeric vector | function handle
Range of vertical translation applied to the input image, specified as the
comma-separated pair consisting of 'YTranslation'
and one of the
following. Translation distance is measured in pixels.
2-element numeric vector. The second element must be larger than or equal to the first element. The vertical translation distance is picked randomly from a continuous uniform distribution within the specified interval.
function handle. The function must accept no input arguments and return the vertical translation distance as a numeric scalar. Use a function handle to pick vertical translation distances from a disjoint interval or using a nonuniform probability distribution. For more information about function handles, see Create Function Handle.
By default, the transformation tform
does not translate
images in the vertical direction.
Example: [-5 5]
Output Arguments
tform
— Affine transformation
affine2d
object
Affine transformation, specified as an affine2d
object.
Version History
See Also
imwarp
| randomAffine3d
| randomWindow2d
| centerCropWindow2d
Topics
- Augment Images for Deep Learning Workflows Using Image Processing Toolbox (Deep Learning Toolbox)
MATLAB 명령
다음 MATLAB 명령에 해당하는 링크를 클릭했습니다.
명령을 실행하려면 MATLAB 명령 창에 입력하십시오. 웹 브라우저는 MATLAB 명령을 지원하지 않습니다.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)