face_detection

Detects the faces and the eyes with the Haar cascade classifiers (cv::CascadeClassifier). See dnn_face_detection for the DNN based face detection.

opencv_apps	1.11 and later (ROS 1), 3.0.0 and later (ROS 2)
ROS	noetic, ROS One, jazzy, kilted, lyrical and later
OpenCV	any version of the distributions
Group	Faces, the nodes of which publish `~/faces` (FaceArrayStamped)

Usage

# ROS 2
ros2 launch opencv_apps face_detection.launch.xml image:=/camera/image_raw debug_view:=false
# ROS 1
roslaunch opencv_apps face_detection.launch image:=/camera/image_raw debug_view:=false use_opencv4:=true

Try it with the demo video

Download the input video of the demo above, publish it as image with image_publisher, and run the node on it, in the terminals:

wget https://ros-perception.github.io/opencv_apps/media/clips/tos_faces.mp4
# terminal 1: publish the video as image in a loop
ros2 run image_publisher image_publisher_node tos_faces.mp4 --ros-args -p publish_rate:=10.0 -r image_raw:=image
# terminal 2: run the node
ros2 launch opencv_apps face_detection.launch.xml image:=image
# terminal 3: view the result
ros2 run rqt_image_view rqt_image_view /face_detection/image

In ROS 1:

# terminal 1
rosrun image_publisher image_publisher tos_faces.mp4 _publish_rate:=10 __name:=camera
# terminal 2
roslaunch opencv_apps face_detection.launch image:=camera/image_raw use_opencv4:=true

See Credits of the demo videos for the license of the video.

Subscribed topics

Topic	Type
`image`	`sensor_msgs/msg/Image`

Published topics

Topic	Type
`~/face_image`	`sensor_msgs/msg/Image`
`~/faces`	opencv_apps/msg/FaceArrayStamped
`~/image`	`sensor_msgs/msg/Image`

Parameters

Source

src/nodelet/face_detection_nodelet.cpp, launch/face_detection.launch.xml

Name	Type	Default (range)	Changed at run time	Description
`eyes_cascade_name`	string	“/usr/share/opencv4/haarcascades/haarcascade_eye_tree_eyeglasses.xml”	no, restart the node	Eye dtection cascade Filename
`face_cascade_name`	string	“/usr/share/opencv4/haarcascades/haarcascade_frontalface_alt.xml”	no, restart the node	Face dtection cascade Filename
`queue_size`	int	3	no, restart the node	Specigy queue_size of input image subscribers