Authors: Zehua Cheng, Wei Dai, Wenhu Zhang, Thomas Lukasiewicz, Jiahao Sun
Organizations: Department of Computer Science, University of Oxford · Department of Computer Science and Engineering, Hong Kong University of Science and Technology · Institute of Logic and Computation, TU Wien
A user pointing their phone at a supermarket shelf and asking "Which soda has the least sugar?" poses a difficult challenge for current visual Al assistants. Such queries require not only object recognition, but explicit set-based reasoning such as filtering, comparison, and aggregation. Standard endto-end MLLMs often fail at these tasks because they lack an explicit mechanism for compositional logic. We propose treating visual reasoning as Visual Program Synthesis, where the model first generates a symbolic program that is executed by a separate engine grounded in visual scenes. We also introduce Set-VQA, a new benchmark designed specifically for evaluating set-based visual reasoning. Experiments show that our approach significantly outperforms state-of-the-art baselines on complex reasoning tasks, producing more systematic and transparent behavior while substantially improving answer accuracy. These results demonstrate that program-driven reasoning provides a principled alternative to black-box visual-language inference.
Figures & tables
Fig. 1: An Example of Visual Set Programmer with CASTER in Action Comparing with End-to-End Multi-modal LLM.
Fig. 2: Visual Set Program Synthesizer is a framework for solving complex visual queries by explicitly introducing a structured machine-readable program language. The MLLM generates a program, which is then run by the Program Execution Engine. This engine relies on a perception stack (e.g., object detection, OCR) and a knowledge base to ground the program’s set operations (e.g., FILTER, SELECT) in the visual scene and retrieve necessary attributes.
Model
Type
Set-VQA (PA/AA)
GQA-Set (PA/AA)
PTR-Count (PA/AA)
End-to-End Baselines
Qwen2.5-VL-72B
End-to-End
N/A / 38.6%
N/A / 35.1%
N/A / 25.4%
CogVLM-17B
End-to-End
N/A / 37.5%
N/A / 34.2%
N/A / 24.0%
InternVL-2.5-26B
End-to-End
N/A / 36.4%
N/A / 33.7%
N/A / 23.1%
Qwen2.5-VL-32B
End-to-End
N/A / 36.1%
N/A / 32.8%
N/A / 23.9%
LLaVA-1.6-72B
End-to-End
N/A / 34.8%
N/A / 31.5%
N/A / 22.4%
TABLE I: Main performance comparison on Set-VQA, GQA-Set, and PTR-Count benchmarks. PA and AA denote Program Accuracy and Final Answer Accuracy, respectively. Best results are in bold , second best in underline
Model
Params
Inf. Setting
Single-Step AA
Multi-Hop AA
Extrema AA
Exclusion AA
Overall AA
Qwen2.5
72B
St.
46.2
31.5
29.8
25.1
38.6
Aug.
51.4
36.1
31.2
28.6
42.1
LLaVA1.6
72B
St.
42.1
28.6
24.5
21.0
34.8
Aug.
46.8
32.5
26.8
23.4
37.9
Qwen2.5
32B
St.
43.8
29.4
27.1
22.8
36.1
Aug.
47.5
33.8
28.5
24.9
39.4
TABLE II: Comparison of end-to-end models versus CASTER under standard (St.) and knowledge-augmented (Aug.) inference settings on the Set-VQA test subset. Augmented baselines receive the same external knowledge as CASTER’s execution engine, injected directly into text prompts. VP = VisProg, VG = ViperGPT, CR = CASTER.
Model
Overall (AA)
Task#1 (PA/AA)
Task#2 (PA/AA)
Task#3 (PA/AA)
Task#4 (PA/AA)
Task#5 (PA/AA)
CASTER (Qwen)
88.90%
90.5% / 89.5%
91.2% / 90.1%
89.5% / 88.1%
87.2% / 86.5%
85.1% / 83.4%
CASTER (LLaVA)
87.50%
89.1% / 88.3%
90.3% / 89.2%
88.0% / 86.8%
85.9% / 84.9%
83.5% / 81.9%
RLVR (Qwen)
74.50%
78.2% / 75.1%
79.9% / 76.3%
71.3% / 68.2%
65.0% / 61.7%
63.8% / 59.5%
SFT (Qwen)
58.20%
61.3% / 55.4%
63.8% / 60.1%
55.1% / 51.5%
49.8% / 44.3%
47.2% / 41.1%
Qwen2.5-VL-72B
21.30%
N/A / 19.8%
N/A / 22.5%
N/A / 15.1%
N/A / 9.8%
N/A / 11.2%
CogVLM-17B
20.10%
N/A / 18.5%
N/A / 21.1%
N/A / 13.5%
N/A / 8.5%
N/A / 10.5%
TABLE III: Detailed Compositional Generalization Performance. We evaluate on increasingly complex compositions, including logical exclusion ( FILTER_NOT ), multi-level comparisons ( MAX(ATTR, SORT) ) (Task#4), and combined spatial reasoning ( COUNT(FILTER_SPATIAL) ) (The Task#5). Task#1 refers to Unseen COUNT(SORT); Task#2 refers to Unseen SORT(FILTER); The Task#3 refers to Unseen Exclusion FILTER_NOT.
Model
PA (mean±std)
AA (mean±std)
CASTER (Full)
95.1(±0.4)%
93.8(±0.3)%
w/ Type-Only Match
91.2(±0.7)%
89.5(±0.6)%
w/ Binary Reward
85.4(±1.0)%
84.0(±1.1)%
w/ Normalized Reward
94.8(±0.5)%
93.5(±0.4)%
RLVR
79.5(±1.2)%
86.1(±0.9)%
TABLE IV: Ablation of CASTER reward components on Set-VQA test set.
Logic Operation
Depth
Std. PA
Std. AA
Logic Gap
Perc. Gap
FILTER (Color)
1
98.1
96.8
1.9
1.3
FILTER (Shape)
97.9
96.5
2.1
1.4
FILTER (Texture)
97.0
95.2
3.0
1.8
FILTER (Brand/OCR)
95.5
92.4
4.5
3.1
COUNT (Basic)
98.5
97.1
1.5
1.4
EXISTS (Basic)
99.1
98.2
0.9
0.9
TABLE V: Fine-grained error analysis of CASTER (Qwen2.5-VL-7B) on Set-VQA. Standard vs. Oracle Executor results isolate the perception gap across logic operations and query depths.
What does it take to build a visual reasoner that works across charts, science, spatial understanding, and open-ended tasks? The strongest vision-language models (VLMs) suggest that broad visual reasoning is within reach, yet their closed data and reinforcement learning (RL) pipelines make their gains difficult to study, reproduce, or extend. We introduce Vero, a family of fully open VLMs that match or exceed existing open-weight models across diverse visual reasoning tasks. We scale RL data and rewards across six broad task categories, constructing Vero-600K, a 600K-sample dataset from 59 datasets, and designing task-routed rewards that handle heterogeneous answers. Across VeroEval, our 30-benchmark suite, Vero-600K outperforms existing RL datasets under controlled comparisons. Applied to five starting models, Vero variants gain 2.9-5.4 points on average over their initial models. Notably, Vero-Qwen3I-8B, trained on the Instruct model, surpasses Qwen3-VL-8B-Thinking by 3.8 points on average without additional distillation. Systematic ablations reveal that different task categories elicit distinct reasoning patterns and that broad gains depend on learning them jointly rather than in isolation. All data, code, and models are publicly available.
Visual Question Answering (VQA) is the task of answering questions about images, requiring the integration of multimodal input and reasoning. Modular approaches that incorporate logic-based representations into the reasoning component offer clear advantages over end-to-end trained systems, particularly in terms of interpretability. However, adapting or extending these representations when task requirements change can place a significant burden on developers. To address this challenge, we present an approach for distilling rules from Large Language Models (LLMs). Our method prompts an LLM to extend an initial VQA reasoning theory, expressed as an answer-set program, to meet new requirements of the task. Examples from VQA datasets guide the LLM, validate the results, and help correct erroneous rules by leveraging feedback from the ASP solver. We demonstrate that our approach is effective across diverse VQA datasets. Notably, only a few examples are needed to elicit correct rules from LLMs. Our experiments suggest that rule distillation from LLMs is a promising alternative to traditional data-driven rule learning approaches. Under consideration in Theory and Practice of Logic Programming (TPLP).
Thomas Eiter, Nelson Higuera Ruiz, Johannes Oetsch
Vienna University of Technology (TU Wien), Favoritenstrasse 9–11, Vienna, 1040, Austria · Jönköping University, Gjuterigatan 5, 551 11 Jönköping, Sweden
Recent multimodal large language models (MLLMs) achieve strong performance on visual reasoning benchmarks, yet it remains unclear to what extent such performance reflects reasoning directly grounded in visual evidence. We introduce VisReason, a benchmark for vision-centric reasoning in everyday scenarios where perception and inference are tightly coupled. VisReason contains 1,505 questions across 10 categories spanning perceptual, structural, and conceptual reasoning. Our evaluation shows that VisReason poses a qualitatively different challenge from existing benchmarks, exposing substantial gaps between humans and current MLLMs and revealing limited benefits from test-time reasoning strategies. VisReason offers a focused diagnostic for evaluating vision-centric reasoning beyond language.
Longteng Guo, Yifan Wang, Pengkang Huo +4
Institute of Automation, Chinese Academy of Sciences · School of Artificial Intelligence, University of Chinese Academy of Sciences