Visualize distortion on the frame after a calibration camera procedure

Dear all, I am wondering how I can display the distortion map on the image that I am going to use.

More in detail, by means of camera calibration toolbox provided by Caltech University there is a function to display the distortion map as in the attached figure, I would like to do the same by means of the new, built in, toolbox for the calibration of the camera provided in Matlab 2014b.

Can you suggest me the right way?

I would be grateful.

Answer 1

[Dima Lisin]

Hi Alessandro,

There is no built-in function to do this. However, you should be able to write one yourself, using the undistortPoints function. Define a grid of points on your original image, and then call undistortPoints to get their locations in the undistorted image. Subtracting the original locations from the undistorted locations will give you the displacement vectors, which you can display using quiver.

Answer 2

[Image Analyst]

I think you're looking for the quiver() function.

[Alessandro Antonini]

yes, but how can I get the variables to plot by means of quiver function? isn't there an already built function to do this just using the macro-variable coming from the calibration procedure?

[Image Analyst]

I have not actually used quiver yet myself. I though you already had "the distortion map" (a list of vectors) and merely needed a way to display them as a field of arrows.