One coordinate space
The instrument measures every image on the same axes, so two works can be read directly against each other — a painting, an ink scroll, a photograph, a generated frame, with no interpretation needed to bridge them. Pick any two below. The numbers are the differences; the words are yours to add.
These are z-free raw coordinates, not verdicts. A difference is only meaningful if both works were measured through a comparable reproduction chain and scale window — that is why each read is scaled to the same 2600 px window, and why any work kept below it (a copyright-ceiling source) is flagged. Thin-structure measures do not survive resolution changes the way dense-area measures do. When a single axis carries a claim, take it to the null controls before believing it.