BBoxMaskPose v2: Expanding Mutual Conditioning to 3D
Miroslav Purkrabek, Constantin Kolomiiets, Jiri Matas
TL;DR
The paper introduces BMPv2, an enhanced framework for multi-person pose estimation that combines PMPose, a probabilistic, mask-conditioned 2D pose estimator, with SAM-pose2seg, a pose-guided segmentation refinement. This mutual conditioning yields state-of-the-art results on standard COCO data and crowded OCHuman scenes, including surpassing 50 AP on OCHuman and significantly improving instance segmentation. A key insight is that stronger 2D pose quality directly benefits 3D pose estimation when prompted by segmentation masks, demonstrated via SAM-3D-Body prompts. To better evaluate real-world crowded scenes, the authors release OCHuman-Pose, an expanded annotation set addressing missing instances. The work also discusses a high-cost BMPv2+ variant that loops PMPose and SAM-pose2seg to maximize pose accuracy in exchange for computation, and shows domain-shift robustness on unseen data such as infant imagery.
Abstract
Most 2D human pose estimation benchmarks are nearly saturated, with the exception of crowded scenes. We introduce PMPose, a top-down 2D pose estimator that incorporates the probabilistic formulation and the mask-conditioning. PMPose improves crowded pose estimation without sacrificing performance on standard scenes. Building on this, we present BBoxMaskPose v2 (BMPv2) integrating PMPose and an enhanced SAM-based mask refinement module. BMPv2 surpasses state-of-the-art by 1.5 average precision (AP) points on COCO and 6 AP points on OCHuman, becoming the first method to exceed 50 AP on OCHuman. We demonstrate that BMP's 2D prompting of 3D model improves 3D pose estimation in crowded scenes and that advances in 2D pose quality directly benefit 3D estimation. Results on the new OCHuman-Pose dataset show that multi-person performance is more affected by pose prediction accuracy than by detection. The code, models, and data are available on https://MiraPurkrabek.github.io/BBox-Mask-Pose/.
