gs_final, 4000 iterations) with 12000 iterations and a gaussian cap of 100,000 — the only change of the quality experiment that passed its review. Other changes (frame selection, water and motion-blur models, white balance, lossless crops) did not. The two turntables play in sync (same orbit and timing).
| metric | v1 gs_final | v2 gs_v2 | change |
|---|---|---|---|
| iterations | 4000 | 12000 | |
| gaussians | 20,454 | 34,679 | x1.70 |
| training time (optimisation) | 17 min | 81 min | |
| held-out frames (within 0.3 s of a training frame) | 40 (4) | 40 (4) | |
| LPIPS on the fish (lower = closer to the photo) | 0.1853 | 0.1350 | -0.0503 |
| PSNR full crop (dB) | 25.94 | 25.94 | +0.00 |
| PSNR on the fish mask (dB) | 21.28 | 21.54 | +0.25 |
| sharpness ratio render / photo, grain-robust (1 = as sharp as the photo) | 0.162 | 0.279 | x1.73 |
| sharpness ratio, raw | 0.036 | 0.197 | x5.41 |
| sharp match (photo detail reproduced in place) | 0.097 | 0.211 | +0.114 |
| IoU with the SAM mask | 0.917 | 0.908 | -0.009 |
Verdict: better. LPIPS -0.0503, grain-robust sharpness x1.73 (sharper). Differences below 0.0034 LPIPS or x1.12 sharpness are within the run-to-run noise of training.
Held-out frames: fixed per fish (work/quality_exp/<fish>/heldout.json), evaluated identically for both models (test-time fit of pose, colour and bending with the gaussians frozen). Both models were trained on all frames of the same data set, so held-out frames near a training frame favour both equally; this is a like-for-like comparison of the two recipes, not a generalisation test.
Family: Serranidae 100%, Labridae 0%, Scaridae 0% · agreement across crops 98% · 64 crops · bioclip-2.5 (hf-hub:imageomics/bioclip-2.5-vith14, open_clip, zero-shot)

| window | 58:00 – 68:00 |
| visits | 15: 58:45-58:46, 58:49-58:54, 59:20-59:25, 59:33-59:41, 59:52-60:00, 60:02-60:08, 60:40-60:48, 60:51-60:58, 61:53-61:58, 62:06-62:28, 63:07-63:13, 63:32-63:35, 66:50-66:56, 67:00-67:11, 67:34-67:44 |
| frames (10 fps) detected / kept | 1006 / 990 |
| valid poses (10 fps) | 951 |
| frames with background plate | 937 |
| median size | 164.5 px |
| 30 fps frames / valid poses | 1192 / 1024 |
| method | 4D GS, fins + bending + tail (30 fps) |
| model shown | v2 (gs_v2, quality experiment rollout) |
| iterations | 12000 |
| gaussians | 34679 |
| training time | 81 min |
| trainer validation PSNR full / masked | 26.2 / 21.0 dB |
| trainer validation IoU vs SAM mask | 0.904 |
| near-fish band PSNR (fins) | 27.2 dB |
| production status | done |
| visual note (curation) | spotted grouper, Cephalopholis argus-like |






point_cloud.ply (canonical 3D gaussians) · poses_refined.json · model.pt (incl. per-frame 4D params) · species.json · previous version v1: gs_final point_cloud.ply