> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Estimate human poses with sample_hrnet_pose_estimation

The `sample_hrnet_pose_estimation` sample application provides high-precision human pose estimation using ROS 2 nodes. It uses Qualcomm® AI Engine Direct SDK (QNN) for model inference.

It processes input images and publishes the following ROS 2 topics:

* `/pose_estimation_results`: Output images with visualized pose keypoints.
* `/pose_estimation_points`: Raw keypoint coordinates in a structured message format.

<Note>
  **Note**

  * For model information, see [HRNetPose - Qualcomm AI Hub](https://aihub.qualcomm.com/iot/models/hrnet_pose?searchTerm=hrnet).
  * For more information, see [sample\_hrnet\_pose\_estimation](https://github.com/qualcomm-qrb-ros/qrb_ros_samples/tree/main/ai_vision/sample_hrnet_pose_estimation) on GitHub.
</Note>

<video
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  src="https://mintcdn.com/qualcomm-prod/AeBa_PbSuUY_ELHw/SDKs/QIR-SDK-2.0/media/80-65220-2-qirp-sdk-qsg/hrnet_result_image.mp4?fit=max&auto=format&n=AeBa_PbSuUY_ELHw&q=85&s=f2784a287fb4a7c3da865f45a4cd4ef6"
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<p style={{ textAlign: 'center', fontWeight: 'bold' }}>
  Figure: Sample effects of `sample_hrnet_pose_estimation`
</p>

## Pipeline flow for `sample_hrnet_pose_estimation`

<img src="https://mintcdn.com/qualcomm-prod/IP0o0G5fE3MFmCJ8/SDKs/QIR-SDK-2.0/media/80-65220-2-qirp-sdk-qsg/ga1.6-hrnet-pose-estimation.drawio.svg?fit=max&auto=format&n=IP0o0G5fE3MFmCJ8&q=85&s=85fa2db589994d143c009c59de2d8b31" style={{width: "100%"}} width="1259" height="295" data-path="SDKs/QIR-SDK-2.0/media/80-65220-2-qirp-sdk-qsg/ga1.6-hrnet-pose-estimation.drawio.svg" />

<p style={{ textAlign: 'center', fontWeight: 'bold' }}>
  Figure: Pipeline flow for `sample_hrnet_pose_estimation`
</p>

## ROS nodes used in `sample_hrnet_pose_estimation`

| **ROS node**                                                                        | **Description**                                                                                                                                          |
| :---------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [qrb\_ros\_camera](https://github.com/qualcomm-qrb-ros/qrb_ros_camera)              | Qualcomm ROS 2 package that captures images with parameters and publishes them to ROS topics.                                                            |
| [qrb\_ros\_nn\_inference](https://github.com/qualcomm-qrb-ros/qrb_ros_nn_inference) | Loads a trained AI model, receives preprocessed images, performs inference, and publishes results.                                                       |
| [image\_publisher](https://github.com/ros-perception/image_pipeline)                | ROS 2 Jazzy package that publishes the image ROS topic with a local path.                                                                                |
| `hrnet_pose_estimation_node`                                                        | Subscribes to `/image_raw` for image input, performs pose estimation, and publishes results to `/pose_estimation_results` and `/pose_estimation_points`. |

## ROS topics used in `sample_hrnet_pose_estimation`

| **ROS Topic**                  | **Type**                                  | **Published By**             |
| :----------------------------- | :---------------------------------------- | :--------------------------- |
| `/image_raw`                   | `sensor_msgs.msg.Image`                   | `qrb_ros_camera`             |
| `/qrb_inference_input_tensor`  | `qrb_ros_tensor_list_msgs.msg.TensorList` | `hrnet_pose_estimation_node` |
| `/qrb_inference_output_tensor` | `qrb_ros_tensor_list_msgs.msg.TensorList` | `qrb_ros_nn_inference`       |
| `/pose_estimation_results`     | `sensor_msgs.msg.Image`                   | `hrnet_pose_estimation_node` |
| `/pose_estimation_points`      | `geometry_msgs.msg.PolygonStamped`        | `hrnet_pose_estimation_node` |

<Note>
  **Note**

  `/pose_estimation_points` contains the coordinates of 17 key points on the original image. Developers can subscribe to this topic for secondary development. The key points include: nose, left eye, and right eye. The specific correspondence is as follows:

  |  ID |    Body part   |  ID |  Body part  |
  | :-: | :------------: | :-: | :---------: |
  |  1  |      Nose      |  10 | Right wrist |
  |  2  |    Right eye   |  11 |  Left wrist |
  |  3  |    Left eye    |  12 |  Right hip  |
  |  4  |    Right ear   |  13 |   Left hip  |
  |  5  |    Left ear    |  14 |  Right knee |
  |  6  | Right shoulder |  15 |  Left knee  |
  |  7  |  Left shoulder |  16 | Right ankle |
  |  8  |   Right elbow  |  17 |  Left ankle |
  |  9  |   Left elbow   |     |             |
</Note>

## Prerequisites

You have completed the settings in [Set up the environment for running sample applications](./set-up-env-for-sample-app).

## Run out-of-the-box `sample_hrnet_pose_estimation`

<Accordion title="Try me">
  <Steps>
    <Step title="Run the sample on the development kit">
      ```bash title="SSH Session" theme={null}
      # Set up the runtime environment
      source /usr/share/qirp-setup.sh -m
      # Set the ROS_DOMAIN_ID
      export ROS_DOMAIN_ID=123
      # Launch the sample with an image publisher. You can replace 'image_path' with the path to your desired image.
      ros2 launch sample_hrnet_pose_estimation launch_with_image_publisher.py image_path:=/usr/ros/jazzy/share/sample_hrnet_pose_estimation/input_image.jpg
      # Launch the sample hrnet pose estimation node with qrb_ros_camera ros node.
      ros2 launch sample_hrnet_pose_estimation launch_with_qrb_ros_camera.py
      ```
    </Step>

    <Step title="View the results on the host computer">
      1. Start the `rqt`.
         ```bash title="SSH Session" theme={null}
         # YOUR_HOST_IP is the IP address of the Host where you want to view the sample output.
         export DISPLAY=YOUR_HOST_IP:0
         export ROS_DOMAIN_ID=123
         rqt
         ```
      2. Select the following buttons in sequence:
         **Plugins** --> **Visualization** --> **Image View**
      3. Select `pose_estimation_results` to see the results.
      4. Open a new terminal and run the following command to view the `/pose_estimation_points` topic.
         ```bash title="SSH Session" theme={null}
         source /usr/share/qirp-setup.sh -m
         export ROS_DOMAIN_ID=123
         ros2 topic echo /pose_estimation_points
         ```
    </Step>
  </Steps>
</Accordion>

## Build and run `sample_hrnet_pose_estimation`

The following steps build the `sample_hrnet_pose_estimation` package using Dragonwing IQ-9075 Evaluation Kit as an example.

<Accordion title="Try me">
  <Steps>
    <Step title="Build and package on the host computer">
      1. Build the sample application project.
         ```bash theme={null}
         cd <decompressed_workspace>/images/iq-9075-evk/qirpsdk_artifacts/iq-9075-evk/
         tar -zxvf qirp-sdk_<qirp_version>.tar.gz
         cd qirp-sdk
         source setup.sh
         # build sample
         cd <qirp_decompressed_path>/qirp-samples/ai_vision/sample_hrnet_pose_estimation
         colcon build
         ```
      2. Package and push the sample application to the device.
         ```bash theme={null}
         # package and push build result of sample
         cd <qirp_decompressed_path>/qirp-samples/ai_vision/sample_hrnet_pose_estimation/install/sample_hrnet_pose_estimation
         tar -czvf sample_hrnet_pose_estimation.tar.gz lib share
         scp sample_hrnet_pose_estimation.tar.gz root@[ip-addr]:/opt/
         ```
    </Step>

    <Step title="Install and run on the development kit">
      1. Install the sample application.
         ```bash title="SSH Session" theme={null}
         # Install sample package
         tar --no-overwrite-dir --no-same-owner -zxf /opt/sample_hrnet_pose_estimation.tar.gz -C /usr/ros/jazzy/
         ```
      2. Run the sample application with the steps in [Run out-of-the-box sample\_hrnet\_pose\_estimation](#run-out-of-the-box-sample_hrnet_pose_estimation).
    </Step>
  </Steps>
</Accordion>