ROS full FOV in preview

Russ76

How do we write the launch file to get the full size from RGB ISP into the preview image? I need the full width but resolution and height aren't important. The ROS program works with a small grayscale image in its teach and repeat routine. I see letter boxing describes nearly what I want, but I'm not using the NN pipeline this time. This is ROS Noetic.

Luxonis-Adam

Hi, currently we're in progress of developing new architecture for ROS (currently for ROS Humble, but we're going to backport for Noetic). Currently you are able to resize preview by the changing the aspect ratio, but we're going to add some additional methods like letterboxing soon. You can check out the progress here

Russ76

That sounds good! I see one can resize the full frame in Python, but I don't see how to do it in ROS. The ROS documentation was rather lacking, too, I'd say. If I get it working, I could write up a tutorial for you!
Right now, the D-Lite camera is putting out around one frame a second on my Raspberry Pi, with all the other ROS routines working. That's slow! Too slow for good robot work.

Russ76

# Define source and output
camRgb = pipeline.create(dai.node.ColorCamera)
camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_12_MP)
camRgb.setInterleaved(False)
camRgb.setIspScale(1,5) # 4056x3040 -> 812x608
camRgb.setPreviewSize(812, 608)
camRgb.setColorOrder(dai.ColorCameraProperties.ColorOrder.RGB)
# Slightly lower FPS to avoid lag, as ISP takes more resources at 12MP
camRgb.setFps(25)

xoutIsp = pipeline.create(dai.node.XLinkOut)
xoutIsp.setStreamName("isp")
camRgb.isp.link(xoutIsp.input)

This is the code I'd like to enable for sending out in ROS. The preview frame here would be great! However, the ROS modules are in C++. I wonder how to rewrite the rgb_publisher code to send this image out?

erik

Hi Russ76 , DepthAI C++ and Python have exactly the same API, so you can literally just translate the above code into C++ and use it to publish frames (after using depthai bridge to convert depthai ImgFrame to Image ROS msg.
Thanks, Erik

Russ76

Yes, I did that, and it worked! Just a few lines changed. Now image shows a wider scene but is smaller file size. FPS went up 4X. This is great for robots. I can do a pull request if it is wanted.

I'm waiting for the OAK camera with a 150 degree wide view, and a chip that can run SLAM. That will be sweet!

erik

Awesome to hear that it worked! Yep we are all very excited about RVC3 (and upcoming RVC4 - no info yet) as well, as it will unlock so many new possibilities🙂
Thanks, Erik