Question on Image transformation

Hey guys. I have a question on changing the perspective of an image. Using this resource: http://mopage.de/2011/10/perspective/ I found a way to calculate the transformation matrix, but how do I use this to create a new image with the change in perspective?

Thanks for the help!

Answer 1

[Alex Taylor]

Hi Mubeen,

If you have R2013a, you should look at the class projective2d and the function imwarp.

http://www.mathworks.com/help/images/ref/imwarp.html http://www.mathworks.com/help/images/ref/projective2dclass.html

You can use projective2d to compute forward and inverse point transformations. You can use imwarp and projective2d together to form the resampled output image that is produced by applying a projective transformation.

If you are using previous versions of the Image Procesing Toolbox, you should use the analogous workflow with maketform('projective',___) and imtransform.

We refer the transformation you are referring to as a projective transformation in the Image Processing Toolbox.

Answer 2

[Sean de Wolski]

doc imwarp
doc imtransform

Answer 3

[Image Analyst]

See Steve Eddins blog: http://blogs.mathworks.com/steve/2006/08/04/spatial-transformations-defining-and-applying-custom-transforms/

[usman arif]

Hi guys, I am working on the same thing, I want to rotate image I which is gray scale image, by rotation matrix R which is 3x3 matrix. I am trying to use imwarp with projective2d. but the problem is imwarp changes the size of image.. I want the image size to remain same

[Image Analyst]

Call imcrop() or imresize() to make it whatever you want after you've warped it.