Basic ROS node for aruco detection.
Run the launch file and the python executable file separately
Follow this link for setting up OpenCv depending on your ROS-distribution. https://wiki.ros.org/vision_opencv
Sample code used from: https://wiki.ros.org/cv_bridge/Tutorials/ConvertingBetweenROSImagesAndOpenCVImagesPython
I have used my computer's camera as the image source using the usb_cam ROS package. We can also use usb cameras. (For Raspberry pi: raspberry pi camera) Use the rostopic command for finding out the topic. I have subscribed to the "/usb_camera/image_raw" topic. You can even use the "/usb_camera/image_raw/compressed" with the Image_transport ROS package.
I have used the aruco library in python for detecting Aruco Markers using OpenCV. Specify the aruco dictionary in code.