TokenHMR: Advancing Human Mesh Recovery with a Tokenized Pose Representation
<|reference_start|>TokenHMR: Advancing Human Mesh Recovery with a Tokenized Pose Representation: We address the problem of regressing 3D human pose and shape from a single image, with a focus on 3D accuracy. The current best methods leverage large datasets of 3D pseudo-ground-truth (p-GT) and 2D keypoints, leading to robust performance. With such methods, we observe a paradoxical decline in 3D pose accuracy with increasing 2D accuracy. This is caused by biases in the p-GT and the use of an approximate camera projection model. We quantify the error induced by current camera models and show that fitting 2D keypoints and p-GT accurately causes incorrect 3D poses. Our analysis defines the invalid distances within which minimizing 2D and p-GT losses is detrimental. We use this to formulate a new loss Threshold-Adaptive Loss Scaling (TALS) that penalizes gross 2D and p-GT losses but not smaller ones. With such a loss, there are many 3D poses that could equally explain the 2D evidence. To reduce this ambiguity we need a prior over valid human poses but such priors can introduce unwanted bias. To address this, we exploit a tokenized representation of human pose and reformulate the problem as token prediction. This restricts the estimated poses to the space of valid poses, effectively providing a uniform prior. Extensive experiments on the EMDB and 3DPW datasets show that our reformulated keypoint loss and tokenization allows us to train on in-the-wild data while improving 3D accuracy over the state-of-the-art. Our models and code are available for research at https://tokenhmr.is.tue.mpg.de.<|reference_end|>
@article{dwivedi2024tokenhmr:,
    title={TokenHMR: Advancing Human Mesh Recovery with a Tokenized Pose
  Representation},
    author={Sai Kumar Dwivedi, Yu Sun, Priyanka Patel, Yao Feng, Michael J. Black},
    journal={arXiv preprint arXiv:2404.16752},
    year={2024},
    archivePrefix={arXiv},
    eprint={2404.16752},
    primaryClass={cs.CV}
}