A little festive-season project.

It’s basically a pixellation effect that works on polar, rather than cartesian coordinates.
In the 2D Cartesian coordinate system, X and Y coordinates define the left/right and up/down position of a given point. In a Polar coordinate space, a point is defined by its Angle (represented by the Greek letter Phi in my code, but more often Theta is used, apparently) and distance from a centre point (r). The effect converts Cartesian to Polar coordinates, then ‘quantises’ the values of Phi and r to tweakable step-sizes. The effect is to divide the image up into ’slices’ and rings. Easier to demonstrate with a few screenshots than to explain in words, as is usually the case.

Still needs some work, and I’m not quite sure how to deal with the ugly round hole in the centre, but I’m pretty pleased with it so far.

‘Stepping’ the Angle (Phi) parameter

Stepping the radius (r).

…and finally, applying quantisation to both dimensions.

The Cartesian-Polar coordinate code I stole shamelessly from Libero Spagnolini’s Photobooth Demystified page, and the polarPixellate effect is a development of my earlier circle-wipe effect.

I think I’ll do a few more experiments in the future, to see what I can do with rectangular-to-polar coordinates and various distortions.

With thanks to Ed. for code advice and general encouragement and enthusiasm.