README

hri_face_detect

A ROS4HRI-compiant ROS node to perform fast face detection using YuNet face detector and Mediapipe Face Mesh. The former performs well at greater distances (depending on image resolution and image scaling applied) and extracts 5 keypoints. The latter works only at close distances and extracts all the ROS4HRI-defined landmarks.

Installing dependencies

If you are running this package outside PAL, first install all the dependencies:

pip install -r requirements.txt

ROS API

Parameters

All parameters are loaded in the lifecycle configuration transition.

• processing_rate (int, default: 30): Image processing logic execution rate in Hertz.

• image_compressed (bool, default: false): Selects the compressed image transport.

• face_mesh (bool, default: true): It enables the additional Mediapipe Face Mesh detection.

• confidence_threshold (double, default: 0.75): Candidate face detections with confidence lower that this threshold are not published.

• image_scale (double, default: 0.5): The YuNet face detector accepts input image of dynamic size. This parameter controls the rescale factor applied to the input image before running the YuNet face detector. Lower image scale results in less processing time required and lower detection confidences. The output data (e.g., RoI) is invariant with this parameter and always refers to the original input image size.

• filtering_frame (string, default: “camera_color_optical_frame”): The reference frame the estimated face pose should be transformed to before performing the filtering operations. Due to the proximity between the camera frame and the detected faces, and considering that cameras can be mounted on frequently moving robot’s components (e.g., robot’s head), directly filtering a face pose expressed in camera optical frame might reduce the filtering quality.

• deterministic_ids (bool, default: false): If true the face ids start from “f00000” and increases by one for each new face. If false it is a random five letters sequence.

• debug (bool, default: false): If true opens a windows showing the input image with face detections overlayed.

Topics

This package follows the ROS4HRI conventions (REP-155). If the topic message type is not indicated, the ROS4HRI convention is implied.

Subscribed

• image (sensor_msgs/msg/Image): only if image_compressed is false

• image/compressed (sensor_msgs/msg/CompressedImage): only if image_compressed is true; note that the suffix /compressed is added after the remapping is resolved, so you should remap only image regardless of the image_compressed value.

• camera_info (sensor_msgs/msg/CameraInfo)

Published

• /humans/faces/<faceID>/roi

• /humans/faces/<faceID>/landmarks

• /humans/faces/<faceID>/cropped

• /humans/faces/<faceID>/aligned

• /humans/faces/tracked

• /diagnostics (diagnostic_msgs/msg/DiagnosticArray)

Execution

ros2 launch hri_face_detect hri_face_detect.launch.py

Example

For an example of usage, execute in different terminals:

• USB camera:

  1. apt install ros-humble-usb-cam

  2. ros2 run usb_cam usb_cam_node_exe --ros-args -p pixel_format:="mjpeg2rgb"

• HRI face detect:

  1. apt install ros-humble-hri-face-detect

  2. ros2 launch hri_face_detect hri_face_detect.launch.py

• RViz with HRI plugin:

  1. apt install ros-humble-rviz2

  2. apt install ros-humble-hri-rviz

  3. rviz2

In RViz, add the ‘Humans’ plugin to see the detected faces with the relative keypoints.