Large vision-language models (LVLMs) have recently been extended to handle multiple input images, but this extension dramatically increases the visual token budget, making visual-token pruning not merely an efficiency option but a practical necessity. Existing visual-token pruning methods, primarily designed for the single-image setting, rely on attention-derived saliency signals to estimate per-token importance. However, this attention-centric design transfers poorly to the multi-image regime: it causes substantial performance degradation on multi-image benchmarks, suffers from strong positional bias, and loses discriminative attention signals as the number of input images increases. To test whether attention-selected tokens are truly important for multi-image reasoning, we conduct two complementary causal probes Leave-One-In and Leave-One-Deletion, which measure token importance by restoring individual tokens to a zeroed visual sequence or removing them from the full sequence. Attention-based pruners provide only marginal gains over random selection, showing that attention is a weak proxy for visual-token importance in multi-image reasoning. Motivated by this gap, we propose Relation and Information Aware Pruning (RI-Prune), a training-free, attention-free pre-decoder selector for multi-image visual token pruning. RI-Prune scores each visual token using a z-normalized combination of three signals computed from projector outputs: query relevance, cross-image correspondence with compact per-image prototypes, and intra image representativeness. By integrating these signals, RI-Prune performs balanced per-image Top-K selection to preserve information across input images. Across multiple multi-image benchmarks and three LVLM backbones, RI-Prune achieves a stronger trade-off between token reduction and task performance than prior pruning methods, particularly under aggressive token budgets.
Figures & tables
Figure 1. Failure modes of attention-based visual token pruning in multi-image LVLMs. (a) Single-image pruning methods retain high performance on single-image benchmarks but degrade sharply on multi-image benchmarks, showing poor transfer to multi-image reasoning. (b) Query attention becomes unreliable across images: it exhibits positional bias and becomes increasingly non-discriminative as the number of input images grows. (c) CLS-based saliency selects tokens with weaker query alignment than query-driven attention, suggesting that CLS attention is less effective at preserving question-relevant visual evidence.
Figure 2. Method-level information gain over random pruning when retaining 4.6% of visual tokens. Bars report the per-sample average gains ΔILOI and ΔILOD over uniformly random pruning under the same token budget. RI-Prune achieves the largest gains across both benchmarks and metrics, indicating that it retains more answer-relevant visual tokens than attention-based pruning strategies.
Figure 3. Overview of the proposed visual token selection framework. Query relevance ( r ), cross-image correspondence ( c ), and intra-image representativeness ( u ) are computed, normalized, and aggregated to select the Top- K vision tokens for the LLM.
Method
Mantis-Eval
MIBench
MIRB
MUIRBench
Avg.
Vanilla
73.3 [-0.18ex]100.0%
54.6 [-0.18ex]100.0%
63.6 [-0.18ex]100.0%
60.9 [-0.18ex]100.0%
63.1 [-0.18ex]100.0%
Retain 45.3% Tokens
FastV (ECCV’24)
71.9 [-0.18ex]98.1%
54.0 [-0.18ex]98.9%
56.0 [-0.18ex]88.1%
51.5 [-0.18ex]84.6%
58.3 [-0.18ex]92.5%
VisionZip (CVPR’25)
71.9 [-0.18ex]98.1%
52.1 [-0.18ex]95.4%
49.5 [-0.18ex]77.8%
55.9 [-0.18ex]91.8%
57.3 [-0.18ex]90.9%
VTW (AAAI’25)
55.8 [-0.18ex]76.1%
45.6 [-0.18ex]83.5%
42.1 [-0.18ex]66.3%
44.4 [-0.18ex]72.9%
47.0 [-0.18ex]74.4%
DivPrune (CVPR’25)
71.9 [-0.18ex]98.1%
54.4 [-0.18ex]99.6%
60.0 [-0.18ex] 94.3%
59.5 [-0.18ex]97.7%
61.4 [-0.18ex]97.4%
Table 1. Performance comparison across multi-image benchmarks under different pruning ratios. Each cell reports accuracy on the first line and relative performance on the second line.
Method
Mantis-Eval
MIBench
MIRB
MUIRBench
Avg.
Vanilla
61.29 [-0.18ex]100.0%
51.37 [-0.18ex]100.0%
52.27 [-0.18ex]100.0%
36.10 [-0.18ex]100.0%
50.3 [-0.18ex]100.0%
Token Budget 5000
FastV (ECCV’24)
43.9 [-0.18ex]71.6%
42.67 [-0.18ex]83.1%
35.7 [-0.18ex]68.3%
29.6 [-0.18ex]82.0%
38.0 [-0.18ex]75.5%
VisionZip (CVPR’25)
59.0 [-0.18ex]96.3%
49.87 [-0.18ex] 97.1%
50.0 [-0.18ex] 95.7%
34.9 [-0.18ex]96.7%
48.4 [-0.18ex] 96.4%
VTW (AAAI’25)
33.6 [-0.18ex]54.8%
38.00 [-0.18ex]74.0%
39.9 [-0.18ex]76.3%
26.1 [-0.18ex]72.3%
34.4 [-0.18ex]68.5%
DivPrune (CVPR’25)
60.4 [-0.18ex] 98.5%
48.57 [-0.18ex] 94.5%
48.8 [-0.18ex]93.4%
35.7 [-0.18ex] 98.9%
48.4 [-0.18ex]96.2%
Table 2. Comparison with SOTA methods on LLaVA-OneVision-7B under different token budgets. Each cell reports accuracy on the first line and relative performance on the second line. Best results are boldfaced, and second-best results are underlined within each token budget.
Method
Mantis-Eval
MIBench
MIRB
MUIRBench
Avg.
Vanilla
78.7 [-0.18ex]100.0%
60.85 [-0.18ex]100.0%
68.75 [-0.18ex]100.0%
64.4 [-0.18ex]100.0%
68.2 [-0.18ex]100.0%
Retain 23.5% Tokens
FastV (ECCV’24)
69.4 [-0.18ex]88.2%
55.1 [-0.18ex]90.6%
59.3 [-0.18ex]86.3%
60.3 [-0.18ex]93.6%
61.0 [-0.18ex]89.5%
VisionZip (CVPR’25)
74.6 [-0.18ex]94.8%
53.8 [-0.18ex]88.4%
62.4 [-0.18ex]90.8%
60.9 [-0.18ex]94.6%
62.9 [-0.18ex]92.3%
VTW (AAAI’25)
63.7 [-0.18ex]80.9%
48.0 [-0.18ex]78.9%
40.1 [-0.18ex]58.3%
58.5 [-0.18ex]90.8%
52.6 [-0.18ex]77.1%
DivPrune (CVPR’25)
64.7 [-0.18ex]82.2%
51.2 [-0.18ex]84.1%
60.1 [-0.18ex]87.4%
61.0 [-0.18ex]94.7%
59.3 [-0.18ex]86.9%
Table 3. Comparison with SOTA methods on Qwen3-VL under different retained token ratios. Each cell reports accuracy on the first line and relative performance on the second line. Best results are boldfaced, and second-best results are underlined within each retained token ratio.
Variant
λr
λc
λu
r
c
u
Acc.
Δ vs Full
Random
0
0
0
40.1
−10.6
r only
1
0
0
✓
44.6
−6.1
c only
0
1
0
✓
43.1
−7.6
u only
0
0
1
✓
42.4
−8.3
r+c
1
1
0
✓
✓
48.6
−2.1
r+u
1
0
1
✓
✓
41.8
−8.9
Table 4. Ablation study of each component and its corresponding weighting coefficient in RI-Prune. Best result is boldfaced.
Method
Retain Ratio
TFLOPs
Latency
Avg. Acc.
Qwen2.5-VL
100.0%
57.8
8.135s
63.1
FastV
4.6%
11.4
7.728s
44.9
DivPrune
4.6%
8.8
8.074s
48.4
SCOPE
4.6%
8.9
7.953s
48.7
VisionZip
4.6%
8.4
5.217s
46.8
VTW
4.6%
8.5
5.125s
22.9
Table 5. Efficiency and accuracy comparison under different retained token ratios. Results are reported on Qwen2.5-VL.
Selection Mode
Accuracy
Selection Overhead (s)
TFLOPs
Global Top- K
48.8
0.909
7.9
Global + min quota
50.3
0.922
7.9
Per-image Top- K
50.7
0.920
7.9
Table 6. Comparison of token selection modes on Qwen2.5-VL at the 4.6% retained-token setting. Selection overhead is measured in seconds, excluding decoder forward computation.
P
2
4
8
16
64
128
Accuracy
45.6
46.9
47.7
50.7
51.0
48.7
Compute (s)
0.0034
0.0035
0.0038
0.0044
0.0082
0.0116
Table 7. Performance comparison according to the number of prototypes P on Qwen2.5-VL at a 4.6% retained token budget.
Benchmark
Vanilla
FastV
DivPrune
SCOPE
VisionZip
VTW
RI-Prune
Video-MME
63.0
49.3
52.2
47.8
44.9
23.2
52.9
TempCompass
67.0
59.8
63.0
59.0
55.0
33.0
61.0
Table 8. Accuracy comparison on video benchmarks. Acc. denotes accuracy (%). Among pruning methods, the best results are boldfaced and the second-best results are underlined.
Figure 4. Qualitative visualization of visual token pruning on MUIRBench ( Wang et al., 2025 ) . Bright regions indicate retained visual tokens. Colored boxes denote question-relevant regions: green indicates successful preservation, red indicates pruning of critical information, and orange indicates ambiguous preservation that ultimately leads to an incorrect prediction. RI-Prune preserves more relevant visual evidence under aggressive token reduction.