Access AR.Drone camera with OpenCV while connected to ROS

Question

I am having an issue where by I am unable to connect to the AR Drone 2 camera when the drone is connected through ROS using the ardrone_autonomy ardrone.launch.

I think the issue is due to the fact that I am trying to access the drone camera through the IP address with OpenCV and Python while connected through ardrone_autonomy. Below is a code snippet of how I am accomplishing this.

video_capture = cv2.VideoCapture()

video_capture.open('tcp://192.168.1.1:5555')

vidWidth = video_capture.get(cv2.CAP_PROP_FRAME_WIDTH)

vidHeight = video_capture.get(cv2.CAP_PROP_FRAME_HEIGHT)

As you can see that I am using the IP address for the camera. This works perfectly when the drone is not connected through ROS which is essentially like a webcam.

My end goal is for tracking and navigation through the use of images received from the camera using OpenCV which means I will have to issue movement commands(cmd_vel) which requires a connection through ardrone_autonomy based on the images received and processed by OpenCV.

Is there anyway I can accomplish this by using the IP camera from the drone while connected to ROS?

Thanks for any help!

score 1 · Answer 1 · answered Dec 05 '16 at 17:20

http://wiki.ros.org/video_stream_opencv can open a video stream from a HTTP/TCP URL:

<launch>  <!-- video stream from URL to ROS topic - see http://wiki.ros.org/video_stream_opencv  -->
   <include file="$(find video_stream_opencv)/launch/camera.launch" >        
        <arg name="camera_name" value="drone_webcam" /> <!-- node name and ros graph name -->        
        <arg name="video_stream_provider" value="http://192.168.1.227:8080/video?x.mjpeg" /> <!-- ?x.mjpeg see http://answers.opencv.org/question/13139/cvvideocapture-works-for-webcams-but-not-ip-cameras/ --> 
        <arg name="fps" value="10" /><!-- throttling the querying of frames to 10Hz -->        
        <arg name="frame_id" value="webcam" /> <!-- setting TF frame_id -->         
        <arg name="camera_info_url" value="file:///abc/xyz.yaml" /> <!-- camera info loading, take care as it needs the "file:///" at the start , e.g.:
        "file:///$(find your_camera_package)/config/your_camera.yaml" -->        
        <arg name="flip_horizontal" value="false" /> <!-- flip the image horizontally (mirror it) -->
        <arg name="flip_vertical" value="false" /> <!-- flip the image vertically -->        
        <arg name="visualize" value="true" /> <!-- visualize on an image_view window the stream generated -->
   </include>
</launch>

Note the /video?x.mjpeg at the end of the URL.

Access AR.Drone camera with OpenCV while connected to ROS

1 Answers1