backup process not storing images

[stavIatrop]

Hello, I followed the steps for ROS melodic installation and the CMS camera setup as it is described in README and have successfully started registration_approach1_py.launch procedure. However when I run rosrun multispectral_processing backup.py, it doesn't store any image. I am still new to ROS, so I am not really sure, but I think that backup.py doesn't even call callback function(I used a rospy.loginfo() right after the definition of callback and there is no printing). Have you any suggestion/idea of why this may be happening?

[georgealexakis]

The node works only if all 6 topics exist and publish data. I use the ApproximateTimeSynchronizer to subscribe the same time to these topics. I used this node to backup the data in the data folder. If you want to test it, just remove some topic from the subscribtion and the callback.