Is there more information available on using the 'custom' option with the MAKETFORM function in the Image Processing Toolbox?

The documentation for the MAKETFORM function mentions creating custom transformations. I would like further information on the syntax needed to create a custom transformation.

Answer 1

[MathWorks Support Team]

This example goes through the process of creating a radial transformation such as that used to correct the "fish-eye" lens effect.

This function performs the following transformation:

   r_original = p1 + p2*r_final + p3*r_final^2 + p4*r_final^3 +  p5*r_final^4

The coefficients p1, p2, p3, p4, and p5 will depend on the nature of the fisheye lens used. Some may be zero.

The attached files add a mock fisheye effect to the cameraman.tif image included with MATLAB. To run the demo, type:

rundemo

at the MATLAB prompt. This file calls MAKETFORM using the custom transform included in the "radial.m" file. Instructions on how the custom transformation works are included in the comments in the files.