Saving PointCloud from Rosbag

Question

I have to extract images and PCDs from a rosbag file.
I'm using Python 2 and rosbag library to iterate through messages:

import rosbag
from cv_bridge import CvBridge

bag = rosbag.Bag('test.bag')
bridge = CvBridge()
for topic, msg, t in self.bag.read_messages():
    # if image, use bridge
    # but what what to do to save a PointCloud into a PCD?

Is there some library (like cv_bridge) that can help me with extracting PCD from a rosbag?
I found pypcd, but I don't know if it does what I hope it does, as it doesn't work in Python 2, and I can't make rosbag library work in Python 3...

Any idea?

score 3 · Answer 1 · answered Apr 22 '20 at 03:44

3

pcl_ros has a tool to convert pointclouds from a bag file to PCD's.

rosrun pcl_ros bag_to_pcd <input_file.bag> <topic> <output_directory>

answered Apr 22 '20 at 03:44

Shrijit Singh

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score 0 · Answer 2 · answered Jan 18 '20 at 15:19

0

Conversion from message to PointCloud can be done like:

pc = PointCloud.from_msg(msg)

Conversion from PointCloud to message can be done like:

msg = pc.to_msg()

answered Jan 18 '20 at 15:19

Fruchtzwerg

10,999
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Do you do that in Python 2 or 3? The questions was basically how to make pypcd work in Python 2, as installing it through pip requires Python 3. – Lovro Jan 22 '20 at 08:32
In the end, I made it work by manually downloading pypcd code. – Lovro Jan 22 '20 at 08:34
What is "PointCloud" in the first code snippet? – D.Manasreh Dec 08 '22 at 20:08
Imported via ```import pypcd```. See https://buildmedia.readthedocs.org/media/pdf/pypcd/latest/pypcd.pdf – Fruchtzwerg Dec 08 '22 at 21:32

Saving PointCloud from Rosbag

2 Answers2