While Large Vision-Language Models (VLMs) demonstrate impressive general visual capabilities, they remain artistically blind and unable to offer professional evaluation of artworks within specific artistic domains like human experts. To bridge this gap, we transform VLMs into experts capable of professional-grade painting evaluation in the Chinese Artistic Domain, which is more abstract and demands extensive artistic training for evaluation. We introduce HanMo-Bench, a new dataset that features authentic auction-grade masterpieces and AI-generated works, grounded in real-world market valuations. To realize the rigorous judgment, we propose the HanMoVLM and construct a Chain-of-Thought (CoT) validated by experts. This CoT guides the model to perform expert-level reasoning: from content identification and Region of Interest (RoI) localization to professional evaluation, guided by both theme-specific evaluation and typical three-tier evaluation in Chinese paintings. Furthermore, we design a reward function to refine the reasoning process of the HanMoVLM to improve the accuracy. We demonstrate that HanMoVLM can serve as a critical backbone for Test-time Scaling in image generation. By acting as a high-quality verifier, HanMoVLM enables generative models to select the most artistically superior outputs from multiple candidates. Experimental results and human studies confirm that the proposed HanMoVLM effectively bridges the gap, achieving a high consistency with professional experts and significantly improving the quality of Chinese Painting generation.
Figures & tables
Figure 1: The motivation of our study. (a) Generic VLMs suffer from artistic misalignment, evaluation gaps, and low-quality data when handling domain-specific artistic content such as Chinese paintings; (b) The expert-level VLMs introduce the structured expert chain-of-thought, to produce reliable final scores; (c) Experimental results show that our CoT and RL significantly improve performance.
Figure 2: The overall framework of HanMoVLM. For visual artistic understanding, we finetune HanMoVLM with expert-level CoT and expert answer via SFT, and then perform RFT based on the expert reward function. For visual artistic generation, we apply the frozen HanMoVLM as the external verifier to evaluate the images sampled from existing T2I models.
Figure 3: The expert-level Chain-of-Thought in our HanMoVLM. When the generic VLM evaluates Chinese paintings, the model tends to generate outputs based on general knowledge (non-expert) rather than following professional guidelines. As a result, its analysis does not reflect the experts’ procedures, leading to a decline in terms of professional level, reliability, hallucination, and human logic.
Figure 4: Composition of HanMo-Bench.
Figure 5: The construction pipeline of HanMo-Bench.
Model
Size
MAE↓
RMSE↓
Accuracy(%)↑
BERTScore↑
Proprietary Models
Gemini-3-Flash [ 13 ]
-
0.9883
1.3472
31.17
–
+ Thinking
-
0.9633
1.4355
34.83
0.3052
+ Expert CoT
-
0.9466
1.3351
37.00
0.3035
Gemini-3-Pro [ 13 ]
-
0.9866
1.3589
33.83
–
+ Thinking
-
0.9783
1.3311
35.17
0.2855
Table 1: The comparison of our HanMoVLM with other models. 10 and 10 indicate the best and second best results, respectively.
Model
Size
mIoU↑
BERTScore(RoI)↑
Theme↑
Qwen3-VL-Instruct
4B
0.0821
0.2852
0.7346
HanMoVLM (SFT)
4B
0.2708
0.4963
0.8305
HanMoVLM (RFT)
4B
0.2917
0.4911
0.8411
Qwen3-VL-Instruct
8B
0.1401
0.3214
0.7218
HanMoVLM (SFT)
8B
0.2835
0.4872
0.8355
HanMoVLM (RFT)
8B
0.3193
0.5126
0.8515
Table 2: The comparison in mIoU and Theme identification of our VLM with other models.
Figure 6: Generated results in different ratings groups (zoom in for details).
Figure 7: Generated results with the same prompt across different ratings.
Racc
RBERT
RmIoU
Accuracy (%) ↑
BERTScore ↑
mIoU ↑
✓
✓
42.18
0.5529
0.2914
✓
✓
42.36
0.5492
0.2728
✓
✓
39.82
0.5562
0.2902
✓
✓
✓
42.50
0.5568
0.2917
Table 3: The ablation study of using different rewards.
Figure 11Figure 12
Figure 12: The case of RoI in HanMoVLM and the corresponding predicted description and gt description in HanMoVLM. Zoom in for more details.
Rating Type
Top-1 Accuracy ↑
Accuracy ↑
Kendall’s τ↑
Spearman’s ρ↑
Aesthetic Score
0.045
0.125
-0.258
-0.282
PickScore [ 20 ]
0.409
0.341
0.106
0.073
HPSv2.1 [ 42 ]
0.364
0.193
-0.151
-0.173
GPT-4
0.227
0.341
0.197
0.218
GPT-5.1
0.273
0.364
0.121
0.209
HanMoVLM-8B
0.818
0.682
0.758
0.845
Table 4: Comparison of ranking accuracy in different models.
Figure 13: Visual results grouped by the score from our HanMoVLM. Zoom in for details.
Vision-language model-as-a-judge uses multimodal models to assess images, video, and visual-agent outputs against instructions, rubrics, or human preferences.