rqt_bag GUI does not display image messages
My OS is Ubunutu 20.04 using ROS Noetic and python version Python 2.7.18 and graphic card Intel UHD Graphics 620.
Given the bag file from https://open-source-webviz-ui.s3.amaz..., when I run "rqt_bag demo.bag
" the gui is not displaying image messages (i.e no thumbnails on the timeline). In the terminal, I receive the following warning:
Exception in thread Thread-8:
Traceback (most recent call last):
File "/usr/lib/python3.8/threading.py", line 932, in _bootstrap_inner self.run()
File "/opt/ros/noetic/lib/python3/dist-packages/rqt_bag/index_cache_thread.py", line 67, in run updated |= (self.timeline._update_index_cache(topic) > 0)
File "/opt/ros/noetic/lib/python3/dist-packages/rqt_bag/timeline_frame.py", line 838, in _update_index_cache for entry in self.scene().get_entries(topic, start_time, end_time):
File "/opt/ros/noetic/lib/python3/dist-packages/rqt_bag/bag_timeline.py", line 273, in get_entries for entry, _ in bag._mergesort(bag_entries, key=lambda entry: entry.time):
AttributeError: module 'rosbag.bag' has no attribute '_mergesort'
I'd appreciate it if you could help me out