Seeing Through Touch: Tactile-Driven Visual Localization of Material Regions
Authors: Seongyu Kim, Seungwoo Lee, Hyeonggon Ryu, Joon Son Chung, Arda Senocak
Organizations: Korea Advanced Institute of Science and Technology · Hankuk University of Foreign Studies · Ulsan National Institute of Science and Technology
We address the problem of tactile localization, where the goal is to identify image regions that share the same material properties as a tactile input. Existing visuo-tactile methods rely on global alignment and thus fail to capture the fine-grained local correspondences required for this task. The challenge is amplified by existing datasets, which predominantly contain close-up, low-diversity images. We propose a model that learns local visuo-tactile alignment via dense cross-modal feature interactions, producing tactile saliency maps for touch-conditioned material segmentation. To overcome dataset constraints, we introduce: (i) in-the-wild multi-material scene images that expand visual diversity, and (ii) a material-diversity pairing strategy that aligns each tactile sample with visually varied yet tactilely consistent images, improving contextual localization and robustness to weak signals. We also construct two new tactile-grounded material segmentation datasets for quantitative evaluation. Experiments on both new and existing benchmarks show that our approach substantially outperforms prior visuo-tactile methods in tactile localization.
Figures & tables
Figure 2: Pipeline of Seeing Through Touch . Tactile and visual encoders extract features from touch signals and paired images. These features are used to compute visuo-tactile similarities for contrastive learning. We extend visuo-tactile pairing by linking each tactile signal to diverse in-domain (Touch-and-Go) and out-domain (Web-Material) images of the same material category, leveraging the insight that similar materials evoke similar tactile sensations.
Figure 3: Qualitative Tactile Localization Results. Our model localizes more accurately than prior works and baselines across all benchmarks.
Model
TG-Test
Web-Material
OpenSurfaces [ 4 ]
mAP
mIoU
mAP
mIoU
mAP
mIoU
Binary-mask
Full Square
-
67.25
-
32.13
-
18.13
Full Circle
-
61.75
-
34.20
-
18.19
Visual Heatmap
DINOv3 Att. Map [ 36 ]
83.74
74.27
62.73
47.12
18.91
19.04
Table 1: Tactile Localization Results on TG-Test, Web-Material, and OpenSurfaces.
Model
M.D.P.
Start
Middle
End
mAP
mIoU
mAP
mIoU
mAP
mIoU
TG-Test
STT -Local
✗
81.31
72.67
85.12
76.79
81.96
72.68
STT -Indomain
In-domain
86.34
76.15
86.95
77.58
85.51
74.60
STT
Out-domain
86.20
74.56
87.56
76.82
84.54
73.57
Web-Material
Table 2: Robustness to Weaker Tactile Signals. We evaluate our local alignment variants using three types of tactile frames: Start, Middle, and End. M.D.P. denotes material diversity-based pairing.
Figure 4: Touch-and-Go dataset examples. The tactile signal is typically weaker at the beginning and end of a touch instance while strongest in the middle. Models with material diversity-based pairing achieve robust localization regardless of variations in signal strength.
Baselines
Model
TVL [ 14 ]
DINOv3 Att. Map [ 36 ]
GroundedSAM [ 30 ]
Materialistic [ 35 ]
IIoU
1.0
18.0
49.0
83.0
Ours
Model
STT -CLS
STT -Local
STT -Indomain
STT
IIoU
4.0
30.0
32.0
37.0
Table 3: Quantitative Results on Interactive Localization. STT outperforms other methods and shows reliable interactive localization ability.
Figure 5: Qualitative Results on Interactive Localization. Our model accurately localizes the objects corresponding to the given tactile inputs and shifts the localized region appropriately when the tactile signal is changed.
Figure 6: Qualitative Results on Material Replacement. The model interactively and consistently updates localization in response to changes in material and corresponding tactile inputs.
Figure 7: Examples of Touch Instances. Each example shows 10 frames evenly sampled from a touch instance.
Figure 8: Distribution of Frames per Touch Instance.
Figure 9: Prompt for Concept Query Generation.
Figure 10: Custom-built Gradio Page for Dataset Construction.
Figure 11: Prompt for Negative CLIP prompt generation
Figure 12: Positive and Negative Prompts of “Glass” Category for CLIP filtering.
Train
Test
IIoU Test
Category
Web Collected
MINC Curation
Sum
# of samples
# of samples
Concrete
984
-
984
41
9
Plastic
1,000
793
1,793
33
12
Glass
965
1,512
2,477
52
8
Wood
992
1,906
2,898
38
15
Metal
816
1,651
2,467
38
11
Table 4: Category Distribution of the Train, Test, and Interactive Localization Test Sets of the Web-Material Dataset.
Figure 13: Material Diversity Pairing. Each colored borderline corresponds to a sample ID, allowing readers to see which samples are paired.
Figure 14: Visual Comparison of Grounded-SAM and STT.
Model
Method
mIoU
UniTouch + Grounded-SAM
Cascaded
69.40
STT
End-to-End
76.82
Ground-Truth + Grounded-SAM
Cascaded
77.22
Table 5: Comparison of Cascaded and End-to-End Methods.
Model
Material (%)
VT CMC [ 42 ]
54.7
MViTac [ 10 ]
57.6
UniTouch [ 43 ]
61.3
VIT-LENS-2 [ 24 ]
63.0
TLV-Link [ 8 ]
67.2
OmniBind [ 27 ]
67.45
Table 6: Material Classification Linear Probing Accuracy.
Method
TG-Test
Web-Material
OpenSurfaces
mAP
mIoU
mAP
mIoU
mAP
mIoU
T3 (Local)
66.83
68.23
47.79
39.22
27.74
24.95
STT (Local)
85.12
76.79
67.72
52.34
37.25
29.47
T3 (Out-domain)
85.66
74.55
69.83
54.03
38.91
30.19
STT (Out-domain)
87.56
76.82
77.43
60.94
48.06
36.73
Table 7: Ablation on Tactile Backbone.
Figure 15: Qualitative Tactile Localization Results on TG-Test.
Figure 16: Qualitative Tactile Localization Results on Web-Material.
Figure 17: Qualitative Tactile Localization Results on OpenSurfaces.
Figure 18: Qualitative Results on Interactive Localization.
Figure 19: Real-world Scenarios: 360 ∘ views and robot recycling.
Figure 20: Qualitative Results on Artificial Illumination Change.
Figure 21: Qualitative Results on Natural Illumination Change.
Figure 22: Qualitative Results on Material Replacement.
Touch is the primary medium through which humans interact with the environment. Currently, tactile learning mainly focuses on image-level pretraining or alignment. However, tactile signals correspond to local object contact, while research into scale alignment and holographic matching remains limited and proper datasets and benchmarks also lack. To bridge this gap, we first construct a data collection system to acquire a large-scale tactile dataset, with over 20 K tactile contacts from 505 real-world objects. Building on this dataset, we design a Vis-Tac Holographic Matching Benchmark to evaluate vision-tactile local-to-global alignment ability. Then we propose Vision-Tactile Patch Alignment (VTPA) methods for vision-tactile representation learning. Experiments demonstrate that these exceed the performance of methods without alignment and align with whole-object images.
Hong Li, Yankang Dong, Yue Xu +8
Shanghai Jiao Tong University · Ant Group · Shanghai Innovation Institute
Vision and touch are complementary modalities essential for robotic perception and manipulation. While vision provides global object context, touch offers precise local information at contact points. Integrating these modalities for contact localization, i.e., predicting the location of touch on an object's surface, poses significant challenges due to the need for accurate spatial alignment between tactile data and visual geometry. To address this challenge, we propose VTLoc, a novel visual-tactile framework that localizes contact points from tactile readings using a 3D point cloud as visual input. VTLoc introduces two key components: a geometric multi-modal alignment module, which reconstructs a pseudo-point cloud from fused visual-tactile features and aligns it with the visual point cloud to enforce spatial consistencies across modalities; and an iterative localizing updater, which iteratively refines the predicted contact location using fused visual-tactile features. Evaluated on a new benchmark of 100 real-world objects, VTLoc improves single-touch contact localization by reducing local-to-global correspondence ambiguity.
Zhiyuan Wu, Zhuo Chen, Shan Luo
Department of Engineering, King’s College London, Strand, London, WC2R 2LS, United Kingdom
Robots need touch to manipulate objects safely and reliably, as many properties, such as softness, texture, and contact stability, are hard to infer from vision alone. However, vision-based tactile sensors yield different observations of the same material due to variations in optics, elastomer properties, and illumination, leading to poor generalization when trained on a single or multiple sensors. We propose a language-guided distillation framework for learning sensor-robust tactile representations. Language encodes high-level semantic properties of touch (e.g., rough, soft, slippery) that remain invariant across sensing hardware, providing a natural sensor-agnostic supervisory signal. We construct a 39K-sample touch-language dataset with human-annotated material labels and train a tactile encoder to align sensor-specific tactile images with language embeddings in a shared semantic space. We evaluate our approach for few-shot learning and cross-sensor transfer and benchmark it on six existing tactile datasets. Our method achieves 95% accuracy in the 100-shot setting, improves cross-sensor transfer by an average of 13.3% accuracy, and yields up to 19% accuracy gains across six existing tactile datasets. These results demonstrate that language-guided distillation enables scalable and hardware-agnostic tactile representation learning. Code and dataset are available at https://mashood3624.github.io/Language_Tactile/
Mashood M. Mohsan, Muhayy Ud Din, Binzhao Xu +2
Khalifa University Center for Autonomous Robotic Systems (KUCARS), Khalifa University, UAE