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Hello, I am wishing to create a depth-image from my velodyne data. I would like to use a degree paramater (from 0 to 360), the height (y-coordinate) and the depth from the velodyne. I was wondering if you can return what 'degree' the point corresponds to. I've heard that the Velodyne stack is not yet able to return this kind of data.
Thanks!
You are correct: there is currently no conversion to a depth-image. If the device is stationary, that representation could be quite useful. With a moving device, perhaps not, especially when turning.
To do that, one would need to write a package similar to velodyne_pointcloud, but using a different class to unpack the raw data. The logic for unpacking the data is in rawdata.cc. Code to create a polar, cylindrical projection would be a little simpler (less trigonometry). Making a package like that is feasible, but would require significant time and effort. The existing code would definitely provide a useful starting point.
I maintain the Velodyne ROS driver, but have not had much time to devote to it lately. I will gladly provide technical advice if you want to work on it. There are more technical details than would be worthwhile to discuss here, so please open an enhancement issue, if you wish to pursue the idea.
I may look to doing that one day, when I'm not so deeply engrossed in my current research. I'd love to contribute! Would you happen to know if the PCL HDLgrabber has this quality? I took a look at some of the classes and it seems that in the firing class it has the angle, and then in the return class it has the depth. I perfectly understand is this is outside of your well of knowledge though. I really appreciate your prompt help with my questions! Thanks again.
For follow-up, see: https://github.com/ros-drivers/velodyne/issues/26 .
Hi,
If you subscribe run the velodyne_driver you can subscribe "velodyne_packets" (format: velodyne_msgs::VelodyneScan) topic, instead of "velodyne_points" (format: velodyne_msgs::Pointcloud2) and then you will have range of each laser, rotation, intensity and other informations nedded.
With velodyne_points you only have the points XYZ, intensity and laser ring at least.
Good luck
Asked: 2014-04-15 21:24:05 -0500
Seen: 839 times
Last updated: Jun 26 '14
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