digital image processing

I have always been fascinated by the mathematics of digital image processing. In this old image, I am playing my trombone, while on cross country skis, in northern Minnesota.  I performed a 2D Fourier Transform to the digital image, applied a high-pass filter to the 2D spectrum, and inverted back to the spatial domain. The filter purposely had sharp edges, in order to produce Gibbs phenomenon, also known as ringing in many fields of physics. I consider it mathematical art.