RawVLA: Embodied Neural Image Signal Processor For Robotic Manipulation
Organizations: UTokyo · D-Robotics · TohokuU · NTU · HKUSTGZ
Abstract
Vision-language-action (VLA) models typically operate on RGB images produced by a fixed camera image signal processor (ISP), leaving the imaging pipeline outside the learning and evaluation loop. We systematically examine the consequences of this overlooked design choice across five fundamental ISP dimensions: gain, sensor noise, chromatic response, tonal response, and bit depth. Our analysis reveals that RAW-to-RGB processing materially shapes both action prediction and manipulation success, with different ISP dimensions exerting substantially different effects. Guided by these findings, we introduce RawVLA, a streaming neural ISP that adaptively renders RAW observations for frozen VLA policies while concentrating its capacity on the imaging factors relevant to embodied behavior. We further present RawVLA-Bench, a RAW-domain manipulation benchmark to expose image processing as an explicit evaluation variable across clean and adverse acquisition conditions. Experiments on RawVLA-Bench show that RawVLA preserves performance under standard conditions while substantially improving robustness under degraded imaging, establishing adaptive RAW processing as an effective interface between physical cameras and embodied policies.
Figures & tables
| Illumin. | Backbone | Default | DarkISP | RAM | RAWAdapter | RAWild | Ours | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SOG | Long | Avg | SOG | Long | Avg | SOG | Long | Avg | SOG | Long | Avg | SOG | Long | Avg | SOG | Long | Avg | |||
| Extreme Lowlight | PI-0 | 7.87 7.87 | 3.20 3.20 | 6.70 6.70 | 1.93 | 0.00 | 1.45 | 1.80 | 0.00 | 1.35 | 2.80 | 0.00 | 2.10 | 2.87 2.87 | 0.00 | 2.15 2.15 | 46.00 46.00 | 24.80 24.80 | 40.70 40.70 | |
| PI-0.5 | 2.60 | 6.60 | 3.60 | 5.80 5.80 | 9.00 9.00 | 6.60 6.60 | 1.73 | 0.00 | 1.30 | 0.07 | 0.00 | 0.05 | 3.93 3.93 | 8.00 8.00 | 4.95 4.95 | 41.63 41.63 | 30.00 30.00 | 38.72 38.72 | ||
| Qwen3-OFT | 0.00 | 0.00 | 0.00 | 4.13 4.13 | 2.40 2.40 | 3.70 3.70 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.87 0.87 | 2.60 2.60 | 1.30 1.30 | 15.20 15.20 | 10.60 10.60 | 14.05 14.05 | ||
| Lowlight | PI-0 | 68.67 68.67 | 44.60 44.60 | 62.65 62.65 | 2.67 | 0.00 | 2.00 | 1.80 | 0.00 | 1.35 | 2.60 | 0.00 | 1.95 | 6.67 6.67 | 0.40 0.40 | 5.10 5.10 | 90.47 90.47 | 66.00 66.00 | 84.35 84.35 | |
| PI-0.5 | 62.47 62.47 | 50.80 50.80 | 59.55 59.55 | 53.60 | 43.00 | 50.95 | 1.13 | 0.00 | 0.85 | 0.20 | 0.00 | 0.15 | 72.93 72.93 | 60.40 60.40 | 69.80 69.80 | 91.67 91.67 | 81.80 81.80 | 89.20 89.20 | ||
| Illumin. | Backbone | Default | DarkISP | RAM | R.Adp. | RAWild | Ours | |
|---|---|---|---|---|---|---|---|---|
| Extreme Lowlight | PI-0 | 23.62 23.62 | 4.72 | 12.60 12.60 | 1.57 | 8.66 | 32.28 32.28 | |
| PI-0.5 | 17.32 17.32 | 1.57 | 3.15 | 0.00 | 5.51 5.51 | 25.98 25.98 | ||
| Lowlight | PI-0 | 40.94 40.94 | 0.79 | 10.24 10.24 | 3.15 | 6.30 | 59.06 59.06 | |
| PI-0.5 | 51.18 51.18 | 0.00 | 2.36 | 0.00 | 4.72 4.72 | 63.78 63.78 | ||
| Normal | PI-0 | 55.91 55.91 | 34.65 | 17.32 | 56.69 56.69 | 28.35 | 57.48 57.48 | |
| PI-0.5 | 70.87 70.87 | 35.43 | 20.47 | 41.73 41.73 | 40.94 | 67.72 67.72 |
| Illumin. | Backbone | Default | DarkISP | RAM | R.Adp. | RAWild | Ours | |
|---|---|---|---|---|---|---|---|---|
| Extreme Lowlight | PI-0 | 23.62 23.62 | 4.72 | 12.60 12.60 | 1.57 | 8.66 | 32.28 32.28 | |
| PI-0.5 | 17.32 17.32 | 1.57 | 3.15 | 0.00 | 5.51 5.51 | 25.98 25.98 | ||
| Lowlight | PI-0 | 40.94 40.94 | 0.79 | 10.24 10.24 | 3.15 | 6.30 | 59.06 59.06 | |
| PI-0.5 | 51.18 51.18 | 0.00 | 2.36 | 0.00 | 4.72 4.72 | 63.78 63.78 | ||
| Normal | PI-0 | 55.91 55.91 | 34.65 | 17.32 | 56.69 56.69 | 28.35 | 57.48 57.48 | |
| PI-0.5 | 70.87 70.87 | 35.43 | 20.47 | 41.73 41.73 | 40.94 | 67.72 67.72 |
| Illumin. | Task | Default | DarkISP | Ours |
|---|---|---|---|---|
| Normal | pick & place | 96.00 96.00 | 66.00 66.00 | 96.00 96.00 |
| drug drawer | 92.00 92.00 | 52.00 52.00 | 94.00 94.00 | |
| pick flower | 72.00 72.00 | 44.00 44.00 | 66.00 66.00 | |
| stack & cover | 46.00 46.00 | 38.00 38.00 | 44.00 44.00 | |
| Avg | 76.50 76.50 | 50.00 50.00 | 75.00 75.00 | |
| Lowlight | pick & place | 0.00 0.00 | 22.00 22.00 | 92.00 92.00 |
| LIBERO / Qwen3-OFT | RoboTwin 2.0 / PI-0.5 | |||||||||||
| Variant | Ext.Low | Low | Normal | Over | Ext.Over | Avg. | Ext.Low | Low | Normal | Over | Ext.Over | Avg. |
| Photometric descriptors | ||||||||||||
| w/o spatial feature | 0.00 | 20.35 | 97.10 97.10 | 51.15 | 13.15 | 36.35 | 14.96 | 12.60 | 62.99 62.99 | 60.32 | 59.20 | 41.93 |
| w/o luminance descriptor | 27.75 27.75 | 95.05 95.05 | 96.80 | 50.80 | 25.95 | 59.27 | 21.26 | 47.24 | 50.39 | 56.35 | 52.80 | 45.57 |
| w/o chroma descriptor | 0.00 | 0.00 | 96.65 | 48.75 | 16.60 | 32.40 | 23.62 23.62 | 57.48 57.48 | 48.03 | 60.32 | 53.60 | 48.58 |
| Recurrent estimator | ||||||||||||
Appendix figures & tables25 assets
Supplementary material from the paper’s appendix.
Appendix
| Frozen VLA policy | |
|---|---|
| Qwen3-PI | 0.0015 |
| Qwen3-OFT | 0.20 |
| WM4A-Cosmos-GR00T | 0.01 |
| WM4A-Wan-OFT | 0.02 |
| PI0 | 0.15 |
| PI0.5 | 0.10 |
| Method | Spatial | Object | Goal | LIBERO-10 | Avg. |
|---|---|---|---|---|---|
| PI-0 | 78.0 | 84.0 | 82.0 | 22.0 | 66.5 |
| PI-0 with RawVLA | 98.0 98.0 | 96.0 96.0 | 96.0 96.0 | 63.6 63.6 | 88.4 88.4 |
| Improvement (pp) | +20.0 | +12.0 | +14.0 | +41.6 | +21.9 |
| Training objective | LIBERO / Qwen3-OFT | RoboTwin 2.0 / PI-0.5 | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Variant | Ext.Low | Low | Normal | Over | Ext.Over | Avg. | Ext.Low | Low | Normal | Over | Ext.Over | Avg. | |||
| Action loss only | ✓ | 0.00 | 0.00 | 97.75 97.75 | 44.50 44.50 | 29.25 29.25 | 34.30 | 0.00 | 0.00 | 67.72 67.72 | 54.76 54.76 | 46.40 46.40 | 33.70 | ||
| w/o action loss | ✓ | ✓ | 9.50 9.50 | 72.75 72.75 | 97.50 97.50 | 44.25 44.25 | 25.50 25.50 | 49.90 49.90 | 11.81 11.81 | 55.12 55.12 | 62.20 62.20 | 59.52 59.52 | 51.20 51.20 | 47.94 47.94 | |
| Brightness only | ✓ | 4.00 4.00 | 39.50 39.50 | 97.25 97.25 | 41.25 | 21.50 21.50 | 40.70 40.70 | 7.87 7.87 | 41.73 41.73 | 65.35 65.35 | 53.17 | 51.20 51.20 | 43.83 43.83 | ||
| Color only | ✓ | 0.00 | 0.00 | 97.50 97.50 | 43.50 43.50 | 20.00 | 32.20 | 0.00 | 12.60 | 53.54 | 52.38 | 26.40 | 23.73 | ||
| Full RawVLA | ✓ | ✓ | ✓ | 14.05 14.05 | 81.35 81.35 | 96.95 | 43.40 | 20.85 | 51.32 51.32 | 25.98 25.98 | 63.78 63.78 | 67.72 67.72 | 65.08 65.08 | 63.20 63.20 | 57.12 57.12 |
| Variant | Ext.Low | Low | Normal | Over | Ext.Over | Overall | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SOG | Long | Avg | SOG | Long | Avg | SOG | Long | Avg | SOG | Long | Avg | SOG | Long | Avg | SOG | Long | Avg | |
| w/o Exposure | 6.87 | 3.60 | 6.05 | 42.80 | 22.00 | 37.60 | 98.53 98.53 | 92.20 92.20 | 96.95 96.95 | 92.34 92.34 | 60.00 60.00 | 84.25 84.25 | 38.47 | 1.00 1.00 | 29.10 | 55.80 | 35.76 | 50.79 |
| w/o White-balance | 15.87 15.87 | 12.60 12.60 | 15.05 15.05 | 87.46 87.46 | 62.00 62.00 | 81.10 81.10 | 98.53 98.53 | 94.20 94.20 | 97.45 97.45 | 91.67 | 53.00 | 82.00 | 42.80 | 2.00 2.00 | 32.60 | 67.27 67.27 | 44.76 44.76 | 61.64 61.64 |
| w/o CCM | 12.20 12.20 | 12.60 12.60 | 12.30 12.30 | 86.46 | 62.00 62.00 | 80.35 | 97.86 97.86 | 95.20 95.20 | 97.20 97.20 | 92.67 92.67 | 58.00 58.00 | 84.00 84.00 | 43.13 | 2.00 2.00 | 32.85 | 66.47 | 45.96 45.96 | 61.34 |
| w/o Tone-mapping | 7.53 | 5.60 5.60 | 7.05 | 73.46 | 46.00 | 66.60 | 97.53 97.53 | 91.20 | 95.95 | 90.67 | 54.00 | 81.50 | 45.13 45.13 | 2.00 2.00 | 34.35 34.35 | 62.87 | 39.76 | 57.09 |
| Shared tone | 15.20 15.20 | 10.60 10.60 | 14.05 14.05 | 86.80 86.80 | 63.00 63.00 | 80.85 80.85 | 98.53 98.53 | 92.20 92.20 | 96.95 96.95 | 92.00 92.00 | 54.00 | 82.50 82.50 | 47.47 47.47 | 1.00 1.00 | 35.85 35.85 | 68.00 68.00 | 44.16 44.16 | 62.04 62.04 |
| Variant | Ext.Low | Low | Normal | Over | Ext.Over | Avg. |
|---|---|---|---|---|---|---|
| w/o Exposure | 12.60 | 18.11 | 65.35 | 61.11 61.11 | 60.00 60.00 | 43.35 |
| w/o White-balance | 25.98 25.98 | 58.27 58.27 | 66.14 66.14 | 65.08 65.08 | 54.40 | 53.96 53.96 |
| w/o CCM | 25.20 25.20 | 61.42 61.42 | 69.29 69.29 | 57.14 57.14 | 62.40 62.40 | 55.06 55.06 |
| w/o Tone-mapping | 22.05 22.05 | 50.39 | 64.57 | 65.08 65.08 | 60.00 60.00 | 52.37 |
| Full RawVLA | 25.98 25.98 | 63.78 63.78 | 67.72 67.72 | 65.08 65.08 | 63.20 63.20 | 57.12 57.12 |
| Benchmark | Ablation | Setting | Ext.Low | Low | Normal | Average | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| PSNR | SSIM | PSNR | SSIM | PSNR | SSIM | PSNR | SSIM | |||
| LIBERO Qwen3-OFT | Burst length | 18.93 | 0.117 | 19.99 | 0.261 | 36.69 | 0.863 | 25.21 | 0.414 | |
| 20.15 | 0.144 | 21.34 21.34 | 0.304 0.304 | 37.66 37.66 | 0.893 | 26.38 26.38 | 0.447 | |||
| 21.98 21.98 | 0.195 0.195 | 23.27 23.27 | 0.373 0.373 | 37.57 37.57 | 0.921 0.921 | 27.61 27.61 | 0.497 0.497 | |||
| Fusion strength | 19.63 | 0.132 | 20.79 | 0.286 | 37.44 | 0.882 | 25.95 | 0.433 | ||
| 21.98 21.98 | 0.195 0.195 | 23.27 23.27 | 0.373 0.373 | 37.57 37.57 | 0.921 0.921 | 27.61 27.61 | 0.497 0.497 | |||
| Task | Language prompt |
|---|---|
| pick_and_place | Place the green apple, pink object, and yellow banana in the blue bowl. |
| drag_the_drawer | Open the drawer and place the yellow block inside. |
| pick_flower | Pick up the two flowers and place them in the white vase. |
| stack_and_cover | Stack the green and blue blocks and cover them with the pink cup. |
| Illumin. | Backbone | Default | DarkISP | RAM | RAWAdapter | RAWild | Ours |
|---|---|---|---|---|---|---|---|
| Extreme Lowlight | WM4A-Wan | 0.00 | 0.05 | 0.00 | 0.00 | 0.00 | 0.75 |
| WM4A-Cosmos | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | |
| Lowlight | WM4A-Wan | 0.05 | 0.05 | 0.05 | 0.00 | 0.00 | 0.55 |
| WM4A-Cosmos | 0.05 | 0.00 | 0.00 | 0.00 | 0.00 | 0.75 | |
| Normal | WM4A-Wan | 76.10 | 76.50 | 0.00 | 38.05 | 75.15 | 78.20 |
| WM4A-Cosmos | 85.75 | 0.75 | 1.75 | 2.45 | 4.25 | 83.45 |