Prosopon 0.4.2

Aligns hundreds of portrait photographs onto one fixed 2048 × 2048 face grid, so that
fragments of different faces can be cut up and recombined into quartered portraits — four
faces to a canvas, the mouth landing exactly on the seam.

What is in it

Seams matched along their length. A strip is a sixteen-sample profile rather than one
mean, scored on a constant offset and on disagreeing slopes, and a 2-opt pass refines the
greedy plan afterwards. One mean cannot tell two strips with reversed gradients apart, and
an eye sees nothing else. Measured on 204 tiles, 51 composites, seed 1:

                      mean only   + profile   + refinement
  median                  25.92       23.65         21.43
  mean                    27.49       25.11         23.13
  max                     58.77       48.88         48.88
  joins over 25 dE        26/51       22/51         16/51
  joins over 35 dE        10/51        6/51          5/51

Median worst join down 17 %, composites carrying a visible break down by more than a third.

Enough stretch and shear to actually place a mouth. The caps are controls now, they
bound Fine Tune's drag rather than only the batch, and they are recorded in the manifest on
save. At 25 % stretch and 20 % shear the worst mouth error over 204 portraits is 0.0 px —
every mouth exactly on target. The median face is stretched the same either way, so the
extra range is spent only where the mouth was missing.

All four run settings travel with the run — detector, magnification gate, stretch cap,
shear cap. Each is persisted between launches and adopted from the run being opened, rather
than reverting to a built-in default and quietly remaking work at the wrong numbers.

A mix folder is output, and the scanner knows it. Any directory holding a
mix-manifest.json is skipped whole, so a run cannot import its own composites as though
they were photographs. There is no reliable way to tell a composite from a portrait by
looking at it — that is precisely what it was built from.

Mix is a stage in the app, with the seed as a control and every composite's four sources
and seam distances shown underneath it.

Fixes for the launch that produced no window, twenty photographs reported missing while
sitting where they always were, and a save that could not say so.

Install

Prosopon-Review-0.4.2.dmg below. It is ad-hoc signed and not notarised — there is no
Developer ID certificate for this project. On any Mac other than the one that built it,
Gatekeeper will refuse a double-click. Open it once from the context menu, or:

xattr -dr com.apple.quarantine "/Applications/Prosopon Review.app"

Requires macOS 15 or later.

Verification

364 tests in 49 suites, passing.

MIT licensed. The licence covers the source and says nothing about the photographs you feed
it — portraits of identifiable people carry obligations no software licence can grant.