← Back to homepage

RCSPose

Revisiting Category Semantics in Category-Level 6D Object Pose Estimation

Mingxin Tan, Hong Liu, Hua Wang, Jiale Ren, Zhongzien Jiang, Yaxuan He

IEEE/RSJ IROS 2026 · Accepted

RCSPose uses RGB-D observations and category labels to predict 3D position, 3D orientation, and object size for new instances of known categories, without explicit shape priors.

Motivation

Two mugs can have very different shapes, yet share a handle, rim, and body. Category-level pose estimation needs features that capture these shared structures while preserving what makes each instance different.

RCSPose revisits category labels as a guide for learning these features. It combines cleaner depth geometry, semantics from multiple visual-network layers, and category-guided attention to handle shape variation within a category.

Point features on two mugs, without category semantics on the left and with category semantics on the right
Pseudo-colors visualize learned point features. Left: without category semantics. Right: category guidance produces more coherent feature patterns across object parts. Select any figure to view it at full size.

How it works

An instance segmenter supplies object masks and category labels. Camera intrinsics turn the cropped depth image into a point cloud; the model combines this geometry with the RGB crop and category label. It learns from labeled data and needs no object CAD model or category shape template at inference.

RCSPose pipeline with statistical outlier filtering, multi-level DINOv2 semantic fusion, category-aware feature extraction, and rotation, translation, and size heads
Geometry and visual semantics meet under category-guided attention. Three prediction heads recover rotation, translation, and size. The lower panels detail visual-layer fusion and point-cloud filtering.

SOF · Clean geometry

Use local neighbor-distance statistics to remove isolated depth points, then sample a consistent point set and extract geometric features with PointNet++.

MLSF · Fuse visual layers

Learned weights combine features from the last four DINOv2 blocks, bringing together complementary appearance and semantic cues.

CAFE · Use category cues

Category embeddings guide attention over RGB and point-cloud features. The resulting heatmap focuses feature aggregation on category-relevant structures.

Closer look: what each module contributes

On REAL275 at 5° / 2 cm, the simplified baseline scores 56.3%. Adding SOF alone gives 58.4%, MLSF alone 57.5%, and CAFE alone 57.9%; the full model reaches 60.6%. Geometry cleanup and both semantic modules contribute to the final result.

Results

On REAL275, RCSPose reaches 60.6% mAP at 5° / 2 cm, compared with 54.7% for AG-Pose. On HouseCat6D, it reaches 83.6% mAP at 3D IoU ≥ 0.50, compared with 76.9% for AG-Pose.

RCSPose results across three datasets · mAP (%) · higher is better. On narrow screens, scroll horizontally to view every dataset. A dash means the criterion is not reported in the source table.

Pose and size estimation · Reported results
CriterionREAL275CAMERA25HouseCat6D
3D IoU ≥ 0.25——92.3
3D IoU ≥ 0.5083.994.283.6
3D IoU ≥ 0.7580.492.2—
5° / 2 cm60.679.824.6
5° / 5 cm67.483.426.7
10° / 2 cm80.487.356.0
10° / 5 cm88.492.159.9

IoU measures 3D bounding-box overlap. A 5° / 2 cm prediction must satisfy both the rotation and translation limits. The REAL275 evaluation uses both synthetic and real training data. Values come from Tables I and II of the paper.

AG-Pose above and RCSPose below on REAL275 scenes, with enlarged challenging regions such as mug handles
Top: AG-Pose. Bottom: RCSPose. Red boxes show predictions; green boxes show ground truth. Yellow outlines enlarge challenging regions.
Category-wise results and comparisons

Selected comparisons with AG-Pose from Tables III and IV. Bold marks the higher score in each pair, including ties.

REAL275 · mAP (%) at 5° / 2 cm
CategoryRCSPoseAG-Pose
Bottle73.462.0
Bowl94.488.7
Camera4.81.2
Can82.383.4
Laptop69.759.6
Mug38.832.9
Mean60.654.7
HouseCat6D · mAP (%) at 3D IoU ≥ 0.50
CategoryRCSPoseAG-Pose
Bottle90.786.0
Box21.613.9
Can93.696.7
Cup99.999.9
Remote69.137.2
Teapot99.598.5
Cutlery97.793.3
Glass99.999.3
Tube64.045.0
Shoe100.099.5
Mean83.676.9

Performance varies by criterion. For example, on HouseCat6D at 5° / 2 cm, GCE-Pose with shape priors reports 24.8%, compared with 24.6% for RCSPose.

Real-world examples

The paper tests new instances of six known categories in new environments. RGB images and camera intrinsics are captured with OnePose Cap; Depth Anything V2 supplies predicted depth for the model.

Predicted poses and sizes for bottles, bowls, cameras, cans, laptops, and mugs, shown with red 3D boxes and object axes
Qualitative pose and size predictions for new objects within known categories, using predicted depth.

The model still requires depth, so the quality and availability of depth remain practical limits.

Figures and results are from the RCSPose paper, IEEE/RSJ IROS 2026.