MetaRefine: Score Refinement with Multi-Level Features for Image Assessment
Organizations: 1The University of Sydney · 2Indiana University · 3The University of Hong Kong
Abstract
An image's original dimensions, aspect ratio, and composition provide important cues that can affect its technical and aesthetic quality. Image assessment methods use resizing, cropping, padding, or patch sampling to accommodate different input sizes. However, these operations can alter or obscure original geometric and compositional cues. Existing assessment models also encode rich multi-level visual evidence that can be further extracted and exploited to improve existing models. This motivates us to combine visual evidence with original-image geometry for score refinement without changing the original scoring pipelines. In this paper, we introduce MetaRefine, a metadata-aware score refinement architecture whose lightweight residual heads predict score corrections from geometry, multi-level visual features, and the frozen model's original score. Across 100 configurations on 21 datasets, MetaRefine improves PLCC in 88 configurations and SRCC in 85, with average relative gains of 7.55% and 7.10%, respectively. It reduces MAE in 90 configurations and RMSE in 89, with average relative reductions of 23.27% and 21.93%, respectively. The median parameter overhead is only 1.11%. MetaRefine can further improve state-of-the-art (SOTA) assessment models on multiple benchmarks.
Figures & tables
| SRCC | PLCC | MAE | RMSE | ||||||||||
| Assessment model | Base | Ref. | Gain | Base | Ref. | Gain | Base | Ref. | Gain | Base | Ref. | Gain | Params |
| KonIQ-10k (IQA) [ 22 ] - Test/Total: 2,015 / 10,073 | |||||||||||||
| DP-IQA (Student) [ 14 ] | 0.9752 | 0.9781 | +0.30% | 0.9808 | 0.9828 | +0.21% | 0.0312 | 0.0203 | +34.93% | 0.0396 | 0.0285 | +27.97% | 0.26% |
| MANIQA [ 61 ] | 0.9022 | 0.9505 | +5.35% | 0.9280 | 0.9639 | +3.87% | 0.1521 | 0.0292 | +80.79% | 0.1614 | 0.0377 | +76.63% | 0.71% |
| RALI [ 69 ] | 0.9248 | 0.9440 | +2.08% | 0.9410 | 0.9552 | +1.51% | 0.0494 | 0.0354 | +28.36% | 0.0632 | 0.0458 | +27.50% | 0.24% |
| TReS [ 16 ] | 0.9362 | 0.9406 | +0.48% | 0.9461 | 0.9554 | +0.99% | 0.1602 | 0.0348 | +78.29% | 0.1736 | 0.0465 | +73.20% | 0.74% |
| SRCC | PLCC | MAE | RMSE | ||||||||||
| Assessment model | Base | Ref. | Gain | Base | Ref. | Gain | Base | Ref. | Gain | Base | Ref. | Gain | Params |
| AVA (IAA) [ 39 ] - Test/Total: 19,929 / 255,508 | |||||||||||||
| FGAesQ [ 63 ] | 0.8720 | 0.8838 | +1.35% | 0.8676 | 0.8791 | +1.32% | 0.2885 | 0.2719 | +5.75% | 0.3785 | 0.3593 | +5.07% | 0.53% |
| ELTA [ 36 ] | 0.8420 | 0.8569 | +1.77% | 0.8437 | 0.8581 | +1.71% | 0.3110 | 0.2959 | +4.87% | 0.4037 | 0.3864 | +4.27% | 0.62% |
| QPT V2 (IAA) r [ 58 ] | 0.8551 | 0.8555 | +0.05% | 0.8649 | 0.8658 | +0.11% | 0.0307 | 0.0299 | +2.54% | 0.0389 | 0.0381 | +2.03% | 1.08% |
| ArtiMuse [ 5 ] | 0.8265 | 0.8261 | -0.05% | 0.8250 | 0.8249 | -0.01% | 0.3265 | 0.3263 | +0.07% | 0.4249 | 0.4249 | -0.00% | 0.01% |
| Variant | PLCC | SRCC | MAE | RMSE |
|---|---|---|---|---|
| Reference Configuration | ||||
| Full | 0.000% | 0.000% | 0.000% | 0.000% |
| (A) Multi-Level Visual Features | ||||
| w/o visual features | -3.638% | -3.889% | -55.656% | -48.445% |
| Final features only | -0.960% | -1.265% | -5.371% | -5.436% |
| w/o final features | -0.285% | +0.267% | -7.129% | -6.751% |
Appendix figures & tables17 assets
Supplementary material from the paper’s appendix.
Appendix
| Dataset | Train | Val. | Eval. | Configuration-specific settings |
| KonIQ-10k | 7,058 | 1,000 | 2,015 | QCN and MANIQA: 8,058 training images, MANIQA uses an alternative author list. |
| KADID-10k | 8,000 | – | 2,125 | NLNet: author content split, 6,000/2,000/2,125, 17 evaluation contents. |
| SPAQ | 7,910 | 1,086 | 2,129 | QualiCLIP+ and NIMA IR-v2: 9,013/–/2,112, QCN: 8,996/–/2,129. |
| LIVE Challenge | 814 | 117 | 231 | HyperIQA/HyperIQA+NT: 930/–/232, QualiCLIP+: author list, 931/–/231. |
| FLIVE | 121,080 | 30,856 | 7,304 | Default: whole images and cropped regions, DP-IQA and PaQ-2-PiQ: whole images only, 30,270/7,714/1,826. |
| AVA | 235,579 | – | 19,929 | AesCLIP: exposure-separated 248,259/–/7,249. |
| Variant | PLCC | SRCC | MAE | RMSE |
|---|---|---|---|---|
| (A) Multi-Level Visual Features | ||||
| w/o visual features | -3.638% (83) | -3.889% (80) | -55.656% (82) | -48.445% (81) |
| Final features only | -0.960% (75) | -1.265% (73) | -5.371% (73) | -5.436% (77) |
| w/o final features | -0.285% (63) | +0.267% (61) | -7.129% (58) | -6.751% (61) |
| w/o early features | -0.261% (58) | -0.288% (57) | -0.097% (60) | -0.177% (61) |
| w/o middle features | -0.309% (64) | -0.353% (62) | -0.174% (58) | -0.221% (60) |
| Model (Dataset) | PLCC | SRCC | MAE | RMSE | ||||
| Variant | Mean SD | Change | Mean SD | Change | Mean SD | Change | Mean SD | Change |
| TReS (FLIVE) | ||||||||
| Frozen assessment model | 0.6398 | 0.6293 | 0.1317 | 0.1470 | ||||
| Full | 0.7468 ± 0.0008 | 0.00% | 0.7104 ± 0.0007 | 0.00% | 0.0444 ± 0.0001 | 0.00% | 0.0588 ± 0.0001 | 0.00% |
| Final features only | 0.7221 ± 0.0006 | -3.30% | 0.6804 ± 0.0011 | -4.21% | 0.0463 ± 0.0001 | -4.28% | 0.0611 ± 0.0001 | -3.95% |
| Without final features | 0.7424 ± 0.0012 | -0.58% | 0.7079 ± 0.0015 | -0.34% | 0.0450 ± 0.0001 | -1.29% | 0.0595 ± 0.0001 | -1.19% |
| Model (Dataset) | PLCC | SRCC | MAE | RMSE | ||||
|---|---|---|---|---|---|---|---|---|
| Variant | Mean SD | Change | Mean SD | Change | Mean SD | Change | Mean SD | Change |
| MUSIQ (SPAQ) | ||||||||
| Frozen assessment model | 0.6954 | 0.6984 | 0.1824 | 0.2210 | ||||
| Full | 0.9052 ± 0.0005 | 0.00% | 0.9005 ± 0.0005 | 0.00% | 0.0696 ± 0.0001 | 0.00% | 0.0893 ± 0.0002 | 0.00% |
| Final features only | 0.8690 ± 0.0007 | -4.01% | 0.8674 ± 0.0007 | -3.68% | 0.0818 ± 0.0003 | -17.49% | 0.1060 ± 0.0003 | -18.69% |
| Without final features | 0.8921 ± 0.0003 | -1.45% | 0.8887 ± 0.0001 | -1.31% | 0.0746 ± 0.0003 | -7.23% | 0.0958 ± 0.0003 | -7.30% |
| Model (Dataset) | PLCC | SRCC | MAE | RMSE | Added | ||||
|---|---|---|---|---|---|---|---|---|---|
| Heads | Score | Change | Score | Change | Score | Change | Score | Change | params |
| TReS (FLIVE) | |||||||||
| Base | 0.6398 | 0.6293 | 0.1317 | 0.1470 | 0 | ||||
| 1 | 0.7468 ± 0.0008 | -0.05% | 0.7104 ± 0.0007 | -0.07% | 0.0444 ± 0.0001 | -0.08% | 0.0588 ± 0.0001 | -0.09% | 377,153 |
| 3 (Full) | 0.7472 | 0.00% | 0.7109 | 0.00% | 0.0444 | 0.00% | 0.0588 | 0.00% | 1,131,459 |
| 5 | 0.7471 | -0.01% | 0.7107 | -0.02% | 0.0444 | 0.00% | 0.0588 | -0.01% | 1,885,765 |
| Variant | PLCC | SRCC | MAE | RMSE | Added params | ||||
|---|---|---|---|---|---|---|---|---|---|
| TReS (FLIVE) | |||||||||
| Linear, unbounded | 0.7590 ± 0.0000 | +1.70% | 0.7320 ± 0.0000 | +3.18% | 0.1251 ± 0.0000 | -181.50% | 0.1377 ± 0.0000 | -134.04% | 5,892 |
| MLP (32), unbounded | 0.7387 ± 0.0016 | -1.03% | 0.7025 ± 0.0020 | -0.97% | 0.0454 ± 0.0001 | -2.08% | 0.0599 ± 0.0002 | -1.84% | 188,577 |
| MLP (64), Full | 0.7463 ± 0.0010 | 0.00% | 0.7094 ± 0.0016 | 0.00% | 0.0444 ± 0.0000 | 0.00% | 0.0588 ± 0.0001 | 0.00% | 377,153 |
| MLP (128), unbounded | 0.7479 ± 0.0062 | +0.21% | 0.7096 ± 0.0085 | +0.02% | 0.0442 ± 0.0005 | +0.44% | 0.0587 ± 0.0007 | +0.23% | 754,305 |
| MLP (64–64), unbounded | 0.7398 ± 0.0016 | -0.87% | 0.7129 ± 0.0010 | +0.49% | 0.0531 ± 0.0010 | -19.50% | 0.0686 ± 0.0011 | -16.55% | 381,313 |
| Variant | PLCC | SRCC | MAE | RMSE | Added params | ||||
|---|---|---|---|---|---|---|---|---|---|
| MUSIQ (SPAQ) | |||||||||
| Linear, unbounded | 0.9007 ± 0.0000 | -0.53% | 0.8966 ± 0.0000 | -0.46% | 0.1642 ± 0.0000 | -136.26% | 0.1857 ± 0.0000 | -107.99% | 3,076 |
| MLP (32), unbounded | 0.9003 ± 0.0011 | -0.57% | 0.8952 ± 0.0010 | -0.61% | 0.0719 ± 0.0002 | -3.47% | 0.0926 ± 0.0003 | -3.76% | 98,465 |
| MLP (64), Full | 0.9054 ± 0.0004 | 0.00% | 0.9008 ± 0.0005 | 0.00% | 0.0695 ± 0.0002 | 0.00% | 0.0893 ± 0.0002 | 0.00% | 196,929 |
| MLP (128), unbounded | 0.9078 ± 0.0003 | +0.26% | 0.9035 ± 0.0002 | +0.31% | 0.0687 ± 0.0001 | +1.16% | 0.0880 ± 0.0001 | +1.47% | 393,857 |
| MLP (64–64), unbounded | 0.9054 ± 0.0005 | -0.01% | 0.9004 ± 0.0006 | -0.04% | 0.0727 ± 0.0010 | -4.58% | 0.0928 ± 0.0011 | -3.90% | 201,089 |
| Bound | Regression | PLCC | SRCC | MAE | RMSE | Full wins |
|---|---|---|---|---|---|---|
| 0.1875 | Huber | -2.25% (-0.55%) | -2.29% (-0.40%) | -54.97% (-8.01%) | -48.18% (-7.08%) | 61 |
| 0.375 | Huber | -1.38% (-0.30%) | -1.35% (-0.20%) | -45.27% (-3.46%) | -40.41% (-3.06%) | 56 |
| 0.75 | Huber | -0.65% (-0.17%) | -0.75% (-0.05%) | -31.74% (-1.02%) | -29.12% (-0.55%) | 56 |
| 1.5 | Huber | +0.48% (-0.03%) | +0.53% (-0.01%) | -16.76% (-0.08%) | -16.25% (-0.13%) | 47 |
| 3.375 | Huber | +2.04% (0.00%) | +1.73% (0.00%) | -7.13% (0.00%) | -7.51% (-0.01%) | 35 |
| Adaptive (90th percentile) | Huber | +2.02% (-0.03%) | +1.73% (-0.02%) | -7.44% (-0.06%) | -7.85% (-0.08%) | 41 |
| Variant | PLCC | SRCC | MAE | RMSE | ||||
|---|---|---|---|---|---|---|---|---|
| Heads | Change | 95% interval | Change | 95% interval | Change | 95% interval | Change | 95% interval |
| TReS (FLIVE) | ||||||||
| 10 | -0.06% | [-0.00068, -0.00015] | -0.14% | [-0.00132, -0.00068] | +0.05% | [-0.00001, +0.00005] | +0.01% | [-0.00002, +0.00004] |
| PIAA-MIR (Swin-T) (PARA GIAA) | ||||||||
| 10 | -0.01% | [-0.00019, +0.00009] | +0.01% | [-0.00018, +0.00032] | -0.04% | [-0.00005, +0.00001] | -0.04% | [-0.00006, +0.00001] |
| CLIP-IQA+ (L/14) (KonIQ-10k) | ||||||||
| Heads | Median ms/image | Images/s | Allocated MiB | Reserved MiB |
|---|---|---|---|---|
| Charm (AVA) | ||||
| 0 | 72.94 | 13.36 | 1223.93 | 1250.00 |
| 1 | 74.83 | 13.03 | 1231.95 | 1248.00 |
| 3 | 75.40 | 13.26 | 1235.96 | 1266.00 |
| 5 | 75.49 | 13.07 | 1239.96 | 1268.00 |
| 10 | 76.86 | 12.74 | 1249.97 | 1268.00 |
| Model (Dataset) | Train images | Fit (s) | Load (s) | Norm./GPU (s) | Cache GiB | Train feat. GiB | Extract/write 8 (s) |
|---|---|---|---|---|---|---|---|
| Charm (AVA) | 235579 | 5.287 | 0.196 | 57.464 | 10.808 | 7.189 | 0.608/0.003 |
| CLIP-IQA+ (L/14) (KonIQ-10k) | 7058 | 0.843 | 1.147 | 0.278 | 0.205 | 0.141 | 0.669/0.003 |
| NLNet (KADID-10k) | 6000 | 0.963 | 0.357 | 0.051 | 0.056 | 0.031 | 6.682/0.004 |
| MUSIQ (SPAQ) | 7910 | 0.790 | 0.472 | 0.136 | 0.131 | 0.091 | 16.184/0.003 |
| FGResQ (FGRestore) | 14700 | 0.878 | 3.874 | 1.043 | 0.796 | 0.631 | 0.241/0.003 |
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