Illustration of How to Group Pixels into Super-pixels

This appendix explains how to group pixels in a given 2D array into super-pixels, each containing multiple pixels, while maintaining the proper ordering of pixels. Creating super-pixels should group adjacent pixels in both the horizontal and vertical dimensions. If we grouped pixels in super-pixels only along the axis row-by-row, this would be analogous to having a detector with elements that are long horizontally and thin vertically. Our goal is to properly group the pixels for square detector elements.