HDR phase-only hologram: signal-domain reconstruction loss study
8-frame Gumbel/binary hologram · native ROI · no padding · 300 iterations · hard deterministic CVVDP JOD. Ten losses were screened with independent LR selection; the top four were validated at 300 iterations and the top two were run on all 12 HDR scenes.
Conclusion
The strongest gain came from correctly tuning a simple Charbonnier loss: 8.953 → 9.277 JOD. Multi-exposure remained -0.069 behind tuned Charbonnier. RawNeRF/SNR-aware losses were numerically stable but did not survive the four-scene ranking. The 9.372 goal was missed by 0.095 JOD.
Fitted global reconstruction variance: σ²(I) = 7.315e-05 + 0·I + 0.005982·I².
Stage 1: 100-iteration screen
| # | Loss | Best LR | Mean JOD | Min JOD |
|---|---|---|---|---|
| 1 | rawnerf_sg_l2 | 0.02 | 8.9910 | 8.704 |
| 2 | charb | 0.02 | 8.9578 | 8.566 |
| 3 | mulaw_charb_10 | 0.02 | 8.8987 | 8.446 |
| 4 | multiexposure_charb | 0.02 | 8.8750 | 8.430 |
| 5 | holo_vst_charb | 0.02 | 8.8715 | 8.414 |
| 6 | mulaw_charb_100 | 0.02 | 8.8690 | 8.386 |
| 7 | hdrsplat_sg_l1 | 0.02 | 8.8532 | 8.455 |
| 8 | bounded_relative_charb | 0.02 | 8.7467 | 8.306 |
| 9 | holo_snr_charb | 0.02 | 8.6547 | 8.082 |
| 10 | logbin_balanced_charb | 0.02 | 8.6333 | 8.181 |
12-scene final metrics
| Scene | L2 | Old Charb | Luma heatmap | Tuned Charb | Multi-exp | Multi − tuned |
|---|---|---|---|---|---|---|
| Anime2 | 8.448 | 8.100 | 8.774 | 8.268 | 8.195 | -0.073 |
| Bloom | 8.873 | 9.080 | 9.113 | 9.350 | 9.343 | -0.007 |
| Castle | 8.772 | 9.049 | 8.996 | 9.374 | 9.339 | -0.035 |
| Glade | 8.745 | 8.841 | 8.845 | 9.185 | 9.040 | -0.145 |
| Lounge | 9.106 | 9.332 | 9.471 | 9.730 | 9.662 | -0.068 |
| Meridian | 9.058 | 9.227 | 9.302 | 9.572 | 9.513 | -0.059 |
| Rushmore | 8.819 | 8.667 | 8.691 | 8.973 | 8.855 | -0.118 |
| Showgirl | 8.823 | 8.824 | 9.171 | 9.290 | 9.182 | -0.108 |
| Snow | 9.296 | 9.475 | 9.502 | 9.814 | 9.766 | -0.048 |
| Toys | 9.083 | 9.182 | 9.410 | 9.389 | 9.393 | +0.004 |
| Type | 8.486 | 8.471 | 8.499 | 8.865 | 8.741 | -0.124 |
| Water | 8.952 | 9.190 | 9.198 | 9.520 | 9.478 | -0.042 |
Anime2
Tuned Charb JOD 8.268 · Multi-exposure JOD 8.195
Bloom
Tuned Charb JOD 9.350 · Multi-exposure JOD 9.343
Castle
Tuned Charb JOD 9.374 · Multi-exposure JOD 9.339
Glade
Tuned Charb JOD 9.185 · Multi-exposure JOD 9.040
Lounge
Tuned Charb JOD 9.730 · Multi-exposure JOD 9.662
Meridian
Tuned Charb JOD 9.572 · Multi-exposure JOD 9.513
Rushmore
Tuned Charb JOD 8.973 · Multi-exposure JOD 8.855
Showgirl
Tuned Charb JOD 9.290 · Multi-exposure JOD 9.182
Snow
Tuned Charb JOD 9.814 · Multi-exposure JOD 9.766
Toys
Tuned Charb JOD 9.389 · Multi-exposure JOD 9.393
Type
Tuned Charb JOD 8.865 · Multi-exposure JOD 8.741
Water
Tuned Charb JOD 9.520 · Multi-exposure JOD 9.478
