Novel-object 6D pose pipelines depend on front-end hypotheses that retain target instances under clutter and occlusion without overwhelming downstream pose estimation. We introduce Cue-Calibrated Linguistic Object Onboarding (CLON), a training-free proposal-and-matching front-end. CLON converts multi-view CAD renderings into compact linguistic memories that provide object-specific conditioning to a frozen proposal generator. Constructed offline and reused across scenes, these memories augment generic prompts before segmentation; subsequent template verification assigns object identity. As a complementary onboarding step, CLON derives fixed cue weights from template statistics for semantic, appearance, and geometric verification. On seven BOP-Classic-Core datasets, CLON improves detection AP by 8.2 percentage points (pp), segmentation AP by 6.2 pp, and downstream pose AR by up to 4.1 pp over the evaluated CNOS and SAM-6D front-ends. In a real-world localization-to-grasp study under clutter and occlusion with 100 trials per method, CLON's improved localization doubles grasp success relative to the strongest evaluated baseline. Controlled ablations evaluate linguistic conditioning, multi-view construction, and verification. Analysis of a smaller candidate set with higher class-agnostic recall on five datasets.
Figures & tables
Fig. 1: Method Overview. Offline onboarding builds linguistic object memories for target-aware proposal generation and object-set cue weights for calibrated proposal-object scoring.
Fig. 2: Summary of the fixed prompt used to generate linguistic object memories with Qwen-2.5-VL [ 15 ] .
Method
LM-O [ 24 ]
T-LESS [ 25 ]
TUD-L [ 26 ]
IC-BIN [ 27 ]
ITODD [ 28 ]
HB [ 29 ]
YCB-V [ 30 ]
APmean
Detection Results
CNOS (SAM) [ 7 ]
0.392
0.329
0.376
0.204
0.314
0.424
0.495
0.362
CNOS (FastSAM) [ 7 ]
0.430
0.397
0.540
0.225
0.322
0.518
0.573
0.429
SAM-6D (SAM) [ 2 ]
0.465
0.437
0.536
0.261
0.393
0.530
0.517
0.448
SAM-6D (FastSAM) [ 2 ]
0.464
0.458
0.573
0.245
0.419
0.551
0.589
0.471
CLON
0.529
0.552
0.665
0.358
0.465
0.628
0.671
0.553
TABLE I: 2D detection and segmentation results on the seven core BOP datasets. The best and second-best results within each dataset are shown in bold and underline , respectively.
Method
Detection/ Segmentation
LM-O
T-LESS
TUD-L
IC-BIN
ITODD
HB
YCB-V
ARmean
GigaPose † [ 3 ]
CNOS (SAM) [ 7 ]
0.524
0.547
0.472
0.456
0.373
0.600
0.640
0.516
CNOS (FastSAM) [ 7 ]
0.599
0.571
0.635
0.472
0.397
0.721
0.664
0.580
SAM-6D (SAM) [ 2 ]
0.607
0.578
0.651
0.521
0.409
0.728
0.656
0.593
SAM-6D (FastSAM) [ 2 ]
0.600
0.576
0.647
0.477
0.407
0.721
0.667
0.585
CLON
0.620
0.673
0.685
0.567
0.414
0.778
0.699
0.634
SAM-6D [ 2 ]
CNOS (SAM) [ 7 ]
0.607
0.475
0.650
0.498
0.505
0.619
0.788
0.592
TABLE II: 6D pose estimation results using different detection/segmentation and pose estimation methods on the seven core BOP datasets. ( † denotes the use of MegaPose refinement [ 1 ] .) The best and second-best results within each dataset are shown in bold and underline , respectively.
Dataset (# targets)
Detection
# Proposal
Det Memory (GB)
Det Time (s)
Pose Est Time (s)
Total Time (s)
LM-O (8 targets)
CNOS
73
5.20
3.31
1.07
4.38
SAM-6D
112
6.55
3.26
1.75
5.01
CLON
22
5.86
1.02
0.44
1.46
T-LESS (30 targets)
CNOS
62
5.20
2.98
0.80
3.78
SAM-6D
79
6.74
4.08
1.18
5.27
CLON
12
6.37
3.25
0.24
3.49
TABLE III: Latency and memory consumption per image across BOP datasets, using SAM-6D as the pose solver. The best and second-best results within each dataset are shown in bold and underline , respectively.
Method
Metric
LM-O
T-LESS
TUD-L
IC-BIN
ITODD
HB
YCB-V
SAM-6D
Count
174
107
95
108
36
89
80
(SAM)
ARmean
0.650
0.769
0.763
0.495
–
–
0.772
CLON
Count
23
14
5
16
21
14
9
(SAM 3 + LM)
ARmean
0.654
0.818
0.778
0.511
–
–
0.837
TABLE IV: Proposal count and class-agnostic mask recall after proposal consolidation and before proposal–object verification. Proposal count is reported for all seven datasets, while ARmean is reported only for the five datasets with available ground-truth annotations and averages recall over mask IoU thresholds [0.50:0.05:0.95] using all retained proposals and all ground-truth instances. Dashes denote unavailable recall measurements for ITODD and HB.
TABLE V: Ablation of proposal generation, linguistic memory, view aggregation, and verification. (A) fixes the descriptor, CLON verifier, cue weights, and postprocessing while varying the proposal generator and prompt construction. (B) fixes SAM 3 and LM and compares semantic-first verification (SAM-6D), an all-object reference (SAM-6D-All) and CLON . SAM-6D-All and CLON share the proposal–object cue scores, assignment rule, and postprocessing; only their cue weights differ. G-DINO denotes Grounding DINO followed by SAM.
(A) Linguistic Prompt
APmean
(B) Prompt Modality
APmean
Object
0.412
Image
0.008
Object + Color
0.488
Image + LM
0.553
Object + Top-1
0.525
LM ( CLON )
0.553
Object + Top-1 + Color
0.544
–
–
LM ( CLON )
0.553
–
–
TABLE VI: Ablation study of linguistic prompt composition and prompt modality for CLON . The left block evaluates different compositions of linguistic prompts, while the right block compares linguistic and image-based prompt modalities. For each ablation, all other components (SAM 3 and Cue Weight) are fixed to isolate the effect of the prompt. Here, Object denotes the generic prompt set Tgen .
Fig. 3: Qualitative results of LM on T-LESS. (a) The template image of target object (b) The LM generated for each object (c)-(e) SAM 3 segmentation with the generic prompt set, generic + color prompts, and our full LM, respectively.
Fig. 4: Real-world robot deployment under clutter and occlusion. (a) Experimental setup, (b) example test image, and (c) quantitative object detection and grasping success rate.
Fig. 5: Qualitative results of real-world robot deployment. (a) Test image, (b) target object, (c–e) detection results of CNOS, SAM-6D, and CLON , and (f) robot grasping sequence using the CLON detection result.
Object 6D pose estimation formulations have progressively reduced reliance on object-specific priors, evolving from explicit 3D models to multi-view object captures to single reference images. We take this progression to its extreme by introducing prior-free relative 6D pose estimation, which lifts the assumption of knowing which object is to be posed within the scene. This novel setting aims to estimate the relative poses of multiple instances of an unknown object within the same image, without requiring CAD models, templates, or reference images. We solve this by formulating a novel method (PROSE) that finds coarse correspondences between object instances using multimodal foundation features, thus requiring no training. We refine these correspondences by imposing cycle consistency across tuples of instances, and leverage the resulting globally consistent correspondences to estimate the relative 6D pose between any pair of instances. To enable systematic evaluation, we design a novel benchmark (PRENCH) built from three multi-instance BOP datasets and enriched with task-specific metadata. PROSE consistently outperforms baselines obtained by adapting state-of-the-art single-image methods to the proposed setting, while requiring neither task-specific supervision nor additional learned components. Project website: https://tev-fbk.github.io/PROSE/
Behdad Khodabandehloo, Andrea Caraffa, Davide Boscaini +1
Fondazione Bruno Kessler, Trento, Italy · University of Trento, Trento, Italy
6D object pose estimation in cluttered scenes remains challenging due to severe occlusion and sensor noise. We propose MAPRPose, a two-stage framework that leverages mask-aware correspondences for pose proposal and amodal-driven Region-of-Interest (ROI) prediction for robust refinement. In the Mask-Aware Pose Proposal (MAPP) stage, we lift 2D correspondences into 3D space to establish reliable keypoint matches and generate geometrically consistent pose hypotheses based on correspondence-level scoring, from which the top-K candidates are selected. In the refinement stage, we introduce a tensorized render-and-compare pipeline integrated with an Amodal Mask Prediction and ROI Re-Alignment (AMPR) module. By reconstructing complete object geometry and dynamically adjusting the ROI, AMPR mitigates localization errors and spatial misalignment under heavy occlusion. Furthermore, our GPU-accelerated RGB-XYZ reprojection enables simultaneous refinement of all N×B pose hypotheses in a single forward pass. Evaluated on the BOP benchmark, MAPRPose achieves a state-of-the-art Average Recall (AR) of 76.5%, outperforming FoundationPose by 3.1% AR while delivering a 43x speedup in multi-object inference.
Yang Luo, Yan Gong, Yongsheng Gao +2
aState Key Laboratory of Robotics and Systems, Harbin Institute of Technology, Harbin, 150001, China · bSchool of Civil Engineering, Harbin Institute of Technology, Harbin, 150001, China
We present B2TFPose, a training-free zero-shot method for 6DoF pose estimation of unseen objects from RGB images. Using a single frozen DINOv3 vision transformer as its only pretrained component within the pose estimation pipeline, B2TFPose extracts dense patch-level features that generalize across the synthetic-to-real domain gap without any task-specific fine-tuning, revisiting the classical local feature matching paradigm through the lens of large-scale self-supervised foundation models. Three contributions advance the training-free state of the art. A geodesic non-maximum suppression strategy retrieves a viewpoint-diverse template set for coarse-to-fine correspondence matching. Render-guided Re-Correspondence (RRC) synthesizes object-specific views at the estimated pose and re-establishes dense 2D-3D correspondences to sharpen the initial estimate without additional learned parameters. A multi-mask hypothesis selection strategy jointly scores competing segmentation candidates to resolve segmentation ambiguity. On the seven core datasets of the BOP Benchmark, B2TFPose achieves 40.7 mean AR without refinement and 56.4 with refinement, establishing state-of-the-art performance among training-free RGB methods and outperforming trained counterparts including GigaPose and GenFlow, at competitive inference speed.
Ali Rafiaei, Michael Greenspan
Dept. Electrical & Computer Engineering, Ingenuity Labs Queen’s University Kingston, ON, Canada