Méndez Transform app for iPhone and iPad

The Méndez Transform App illustrates how the noncommutative image registration problem can be solved using the Méndez-transform described by Tabea Méndez in her 2016 book "Nichtkommutative Bildverarbeitung". The Méndez transform solves the problem in two steps. In the first step, it finds the axis of rotation. This step actually uses the Méndez transform. In the second step, the rotation angle must be found, but this is much simpler can can easily be done using classical Fourier transform methods.