rtmlib

rtmlib is a super lightweight library to conduct human and animal pose estimation based on RTMPose and ViTPose models WITHOUT any dependencies like mmcv, mmpose, mmdet, etc.

Basically, rtmlib only requires these dependencies:

• numpy
• opencv-python
• opencv-contrib-python
• onnxruntime

Optionally, you can use other common backends like opencv, onnxruntime, openvino, tensorrt to accelerate the inference process.

• For openvino users, please add the path <your python path>\envs\<your env name>\Lib\site-packages\openvino\libs into your environment path.

Contents

1. Installation
2. Quick Start
3. Usage
   1. WebUI
   2. APIs
4. Model Zoo
   1. Detectors
   2. Pose Estimators
   3. Visualization
5. Additional Resources
   1. Citation
   2. Acknowledgement

Installation

• install from pypi:

pip install rtmlib -i https://pypi.org/simple

• install from source code:

git clone https://github.com/Tau-J/rtmlib.git
cd rtmlib

pip install -r requirements.txt

pip install -e .

# [optional]
# pip install onnxruntime-gpu
# pip install openvino

Quick Start

Here is a simple demo to show how to use rtmlib to conduct pose estimation on a single image.

import cv2
from rtmlib import Wholebody, draw_skeleton

img = cv2.imread('./demo.jpg')

device = 'cpu'  # cpu, cuda, mps
backend = 'onnxruntime'  # opencv, onnxruntime, openvino
openpose_skeleton = False  # True for openpose-style (required for animals), False for mmpose-style

wholebody = Wholebody(to_openpose=openpose_skeleton,
                      mode='balanced',  # 'performance', 'lightweight', 'balanced'. Default: 'balanced'
                      backend=backend, device=device)
keypoints, scores = wholebody(img)

# visualize
# if you want to use black background instead of original image,
# img = np.zeros(img.shape, dtype=np.uint8)
img = draw_skeleton(img, keypoints, scores, kpt_thr=0.5, to_openpose=openpose_skeleton)
cv2.imshow('img', img)
cv2.waitKey(0)

Or on a webcam stream or a video file.

from rtmlib import Body, Custom, PoseTracker, draw_skeleton
import cv2

cap = cv2.VideoCapture(0)  # for video file instead of webcam, use cap = cv2.VideoCapture('./demo.mp4')

device = 'cpu'
backend = 'onnxruntime'
openpose_skeleton = False

pose_tracker = PoseTracker(Body,
                        mode='balanced',
                        det_frequency=10,  # detect every 10 frames
                        backend=backend, device=device,
                        to_openpose=False)

# # Or with a custom class
# from functools import partial
# custom = partial(Custom,
#                 det_class='YOLOX',
#                 det='https://download.openmmlab.com/mmpose/v1/projects/rtmposev1/onnx_sdk/yolox_m_8xb8-300e_humanart-c2c7a14a.zip',
#                 det_input_size=(640, 640),
#                 pose_class='RTMPose',
#                 pose='https://download.openmmlab.com/mmpose/v1/projects/rtmposev1/onnx_sdk/rtmpose-m_simcc-body7_pt-body7-halpe26_700e-256x192-4d3e73dd_20230605.zip',
#                 pose_input_size=(192, 256))
# pose_tracker = PoseTracker(custom,
#                         det_frequency=10,
#                         backend=backend, device=device,
#                         to_openpose=False)

frame_idx = 0
while cap.isOpened():
    success, frame = cap.read()
    frame_idx += 1
    if not success:
        break

    keypoints, scores = pose_tracker(frame)

    img_show = frame.copy()
    img_show = draw_skeleton(img_show,
                             keypoints,
                             scores,
                             openpose_skeleton=openpose_skeleton,
                             kpt_thr=0.43)
    cv2.imshow('img', img_show)
    cv2.waitKey(10)

Usage

WebUI

Run webui.py:

# Please make sure you have installed gradio
# pip install gradio

python webui.py

APIs

• Solutions (High-level APIs)
  • PoseTracker
  • Wholebody
  • Body
  • Body_with_feet
  • Hand
  • Animal (bird, cat, dog, horse, sheep, cow, elephant, bear, zebra, giraffe)
  • Custom
  • Wholebody3d
• Detectors (Low-level APIs)
  • YOLOX (human and multiclass)
  • RFDETR (human and multiclass)
  • RTMDet
• Pose Estimators (Low-level APIs)
  • RTMPose
    • RTMPose for 17 keypoints
    • RTMO for 17 keypoints (one-stage)
    • RTMPose for 21 keypoints (hand)
    • RTMPose for 26 keypoints
    • RTMW for 133 keypoints
    • DWPose for 133 keypoints
    • RTMW3D for 133 keypoints (3D)
  • ViTPose
    • ViTPose for 17 keypoints
    • ViTPose for 17 keypoints (animal)
    • ViTPose for 25 keypoints
    • ViTPose for 133 keypoints
• Visualization
  • draw_bbox
  • draw_skeleton

For high-level APIs (Solution), you can choose to pass mode or det+pose arguments to specify the detector and pose estimator you want to use.

# By mode
from rtmlib import Wholebody
wholebody = Wholebody(mode='performance',  # 'performance', 'lightweight', 'balanced'. Default: 'balanced'
                      backend=backend,
                      device=device)

# By det and pose
from rtmlib import Body
body = Body(det='https://download.openmmlab.com/mmpose/v1/projects/rtmposev1/onnx_sdk/yolox_x_8xb8-300e_humanart-a39d44ed.zip',
            det_input_size=(640, 640),
            pose='https://download.openmmlab.com/mmpose/v1/projects/rtmposev1/onnx_sdk/rtmpose-x_simcc-body7_pt-body7_700e-384x288-71d7b7e9_20230629.zip',
            pose_input_size=(288, 384),
            backend=backend,
            device=device)

# By det and pose with custom classes
from rtmlib import Custom
# Human pose estimation using YOLOX and RTMPose
custom = Custom(det_class='YOLOX',
               det='https://download.openmmlab.com/mmpose/v1/projects/rtmposev1/onnx_sdk/yolox_m_8xb8-300e_humanart-c2c7a14a.ip',
               det_input_size=(640, 640),
               pose_class='RTMPose',
               pose='https://download.openmmlab.com/mmpose/v1/projects/rtmposev1/onnx_sdk/rtmpose-m_simcc-body7_pt-body7_420e-256x192-e48f03d0_20230504.zip',
               pose_input_size=(192, 256),
               backend=backend,
               device=device)

# Human and animal pose estimation using YOLOX in multiclass mode and ViTPose
# Requires openpose_skeleton = True in draw_skeleton for visualization
custom = Custom(det_class='YOLOX',
               det_mode='multiclass', # or det_categories=[0,23] (for example)
               det='https://github.com/Megvii-BaseDetection/YOLOX/releases/download/0.1.1rc0/yolox_s.onnx',
               det_input_size=(640, 640),
               pose_class='ViTPose',
               pose='https://huggingface.co/JunkyByte/easy_ViTPose/resolve/main/onnx/apt36k/vitpose-b-apt36k.onnx',
               pose_input_size=(192, 256),
               backend=backend,
               device=device)

For low-level APIs (Model), you can specify the model you want to use by passing the onnx_model argument.

# By onnx_model (.onnx or .zip) by download link or local path
# YOLOX human detector
det_model = YOLOX(onnx_model='https://download.openmmlab.com/mmpose/v1/projects/rtmposev1/onnx_sdk/yolox_s_8xb8-300e_humanart-3ef259a7.zip',
                     backend=backend, device=device)

# YOLOX multiclass detector
det_model = YOLOX('https://github.com/Megvii-BaseDetection/YOLOX/releases/download/0.1.1rc0/yolox_s.onnx',
                     det_mode='multiclass', # or det_categories=[0,1,etc] if you want specific COCO_CLASSES IDs
                     backend=backend, device=device)

# RTMPose pose estimator
pose_model = RTMPose(onnx_model='https://download.openmmlab.com/mmpose/v1/projects/rtmposev1/onnx_sdk/rtmpose-m_simcc-body7_pt-body7_420e-256x192-e48f03d0_20230504.zip',
                     backend=backend, device=device)

# ViTPose pose estimator
pose_model = ViTPose(onnx_model='https://huggingface.co/JunkyByte/easy_ViTPose/resolve/main/onnx/apt36k/vitpose-b-apt36k.onnx',
                     backend=backend, device=device)

Model Zoo

By defaults, rtmlib will automatically download and apply models with the best performance.

More models can be found in RTMPose and ViTPose Model Zoos for pose estimation, and YOLOX for multiclass detection.

All checkpoints hosted on download.openmmlab.com are also mirrored at huggingface.co/Tau-J/RTMPose. If the original OpenMMLab download server is ever unreachable, rtmlib will automatically retry the download from this mirror -- no extra configuration is needed.

Detectors

Hand

ONNX Model	Input Size	AP (hand)	Description
RTMDet-nano	320x320	76.0	trained on 5 datasets

Multi-class

COCO_CLASSES = [
    'person', 'bicycle', 'car', 'motorcycle', 'airplane', 'bus', 'train', 'truck', 'boat', 'traffic light',
    'fire hydrant', 'stop sign', 'parking meter', 'bench', 'bird', 'cat', 'dog', 'horse', 'sheep', 'cow',
    'elephant', 'bear', 'zebra', 'giraffe', 'backpack', 'umbrella', 'handbag', 'tie', 'suitcase', 'frisbee',
    'skis', 'snowboard', 'sports ball', 'kite', 'baseball bat', 'baseball glove', 'skateboard', 'surfboard',
    'tennis racket', 'bottle', 'wine glass', 'cup', 'fork', 'knife', 'spoon', 'bowl', 'banana', 'apple',
    'sandwich', 'orange', 'broccoli', 'carrot', 'hot dog', 'pizza', 'donut', 'cake', 'chair', 'couch',
    'potted plant', 'bed', 'dining table', 'toilet', 'tv', 'laptop', 'mouse', 'remote', 'keyboard',
    'cell phone', 'microwave', 'oven', 'toaster', 'sink', 'refrigerator', 'book', 'clock', 'vase',
    'scissors', 'teddy bear', 'hair drier', 'toothbrush']

ONNX Model	Input Size	AP (COCO classes)	Description
YOLOX-nano	416x416	25.8	trained on coco
YOLOX-t	416x416	32.8	trained on coco
YOLOX-s	640x640	40.5	trained on coco
YOLOX-m	640x640	47.2	trained on coco
YOLOX-l	640x640	50.1	trained on coco
YOLOX-Darknet53	640x640	48.0	trained on coco
YOLOX-X	640x640	51.5	trained on coco

Pose Estimators

Body 17 Keypoints

ONNX Model	Input Size	AP (COCO)	Description
RTMPose-t	256x192	65.9	trained on 7 datasets
RTMPose-s	256x192	69.7	trained on 7 datasets
RTMPose-m	256x192	74.9	trained on 7 datasets
RTMPose-l	256x192	76.7	trained on 7 datasets
RTMPose-l	384x288	78.3	trained on 7 datasets
RTMPose-x	384x288	78.8	trained on 7 datasets
RTMO-s	640x640	68.6	trained on 7 datasets
RTMO-m	640x640	72.6	trained on 7 datasets
RTMO-l	640x640	74.8	trained on 7 datasets
ViTPose++-s	256x192	75.8	trained on 6 datasets
ViTPose++-b	256x192	77.0	trained on 6 datasets
ViTPose++-l	256x192	78.6	trained on 6 datasets

Body 25 Keypoints

ONNX Model	Input Size	AP (COCO)	Description
ViTPose-s	256x192	-	fine-tuned on COCO+feet
ViTPose-b	256x192	-	fine-tuned on COCO+feet
ViTPose-l	256x192	-	fine-tuned on COCO+feet

Body 26 Keypoints

ONNX Model	Input Size	AP (Body8)	Description
RTMPose-t	256x192	68.0	trained on 7 datasets
RTMPose-s	256x192	72.0	trained on 7 datasets
RTMPose-m	256x192	76.7	trained on 7 datasets
RTMPose-l	256x192	78.4	trained on 7 datasets
RTMPose-x*	384x288	80.0	trained on 7 datasets

WholeBody 133 Keypoints

ONNX Model	Input Size	AP (Whole)	Description
ViTPose++-s	256x192	54.4	trained on 6 datasets
ViTPose++-b	256x192	57.4	trained on 6 datasets
ViTPose++-l	256x192	60.6	trained on 6 datasets
DWPose-t	256x192	48.5	trained on COCO-Wholebody+UBody
DWPose-s	256x192	53.8	trained on COCO-Wholebody+UBody
DWPose-m	256x192	60.6	trained on COCO-Wholebody+UBody
DWPose-l	256x192	63.1	trained on COCO-Wholebody+UBody
DWPose-l	384x288	66.5	trained on COCO-Wholebody+UBody
RTMW-m	256x192	58.2	trained on 14 datasets
RTMW-l	256x192	66.0	trained on 14 datasets
RTMW-l*	384x288	70.1	trained on 14 datasets
RTMW-x*	384x288	70.2	trained on 14 datasets

WholeBody 133 Keypoints

ONNX Model	Input Size	AP (Whole)	Description
RTMW3D-x	384x288	68.0	trained on COCO-Wholebody

Hand

ONNX Model	Input Size	AUC (Hand56)	Description
RTMPose-m*	256x256	83.9	trained on 5 datasets

Face

ONNX Model	Input Size	AP (Face6)	Description
RTMPose-t*	256x256	-	trained on 6 datasets
RTMPose-s*	256x256	-	trained on 6 datasets
RTMPose-m*	256x256	-	trained on 6 datasets

Animal

CATEGORIES = ['gorilla', 'spider-monkey', 'howling-monkey', 'zebra', 'elephant', 'hippo', 'raccon', 'rhino', 'giraffe', 'tiger', 'deer', 'lion', 'panda', 'cheetah', 'black-bear', 'polar-bear', 'antelope', 'fox', 'buffalo', 'cow', 'wolf', 'dog', 'sheep', 'cat', 'horse', 'rabbit', 'pig', 'chimpanzee', 'monkey', 'orangutan']

ONNX Model	Input Size	AP (AP10K)	Description
RTMPose-m	256x256	72.2	trained on AP-10K
ViTPose++-s	256x192	74.2	trained on 6 datasets
ViTPose++-b	256x192	75.9	trained on 6 datasets
ViTPose++-l	256x192	80.8	trained on 6 datasets

Visualization

MMPose-style	OpenPose-style

Additional resources

Citation

@misc{rtmlib,
  title={rtmlib},
  author={Jiang, Tao},
  year={2023},
  howpublished = {\url{https://github.com/Tau-J/rtmlib}},
}

@misc{jiang2023,
  doi = {10.48550/ARXIV.2303.07399},
  url = {https://arxiv.org/abs/2303.07399},
  author = {Jiang, Tao and Lu, Peng and Zhang, Li and Ma, Ningsheng and Han, Rui and Lyu, Chengqi and Li, Yining and Chen, Kai},
  keywords = {Computer Vision and Pattern Recognition (cs.CV), FOS: Computer and information sciences, FOS: Computer and information sciences},
  title = {RTMPose: Real-Time Multi-Person Pose Estimation based on MMPose},
  publisher = {arXiv},
  year = {2023},
  copyright = {Creative Commons Attribution 4.0 International}
}

@misc{lu2023rtmo,
      title={{RTMO}: Towards High-Performance One-Stage Real-Time Multi-Person Pose Estimation},
      author={Peng Lu and Tao Jiang and Yining Li and Xiangtai Li and Kai Chen and Wenming Yang},
      year={2023},
      eprint={2312.07526},
      archivePrefix={arXiv},
      primaryClass={cs.CV}
}

@misc{jiang2024rtmwrealtimemultiperson2d,
      title={RTMW: Real-Time Multi-Person 2D and 3D Whole-body Pose Estimation},
      author={Tao Jiang and Xinchen Xie and Yining Li},
      year={2024},
      eprint={2407.08634},
      archivePrefix={arXiv},
      primaryClass={cs.CV},
      url={https://arxiv.org/abs/2407.08634},
}

@article{xu2022vitpose,
      title={Vitpose: Simple vision transformer baselines for human pose estimation},
      author={Xu, Yufei and Zhang, Jing and Zhang, Qiming and Tao, Dacheng},
      journal={Advances in neural information processing systems},
      volume={35},
      pages={38571--38584},
      year={2022}
}

@misc{robinson2025rfdetr,
    title={RF-DETR: Neural Architecture Search for Real-Time Detection Transformers},
    author={Isaac Robinson and Peter Robicheaux and Matvei Popov and Deva Ramanan and Neehar Peri},
    year={2025},
    eprint={2511.09554},
    archivePrefix={arXiv},
    primaryClass={cs.CV},
    url={https://arxiv.org/abs/2511.09554},
}

Acknowledgement

Our code is based on these repos:

• MMPose
• RTMPose
• DWPose
• ViTPose
• RFDETR
• OpenDetect