rosbag doesn't playback at same speed

Hi, I have recorded a rosbag w topics at ~7 Hz. When I use `rosbag play` on those topics, they playback at 2Hz. The `rosbag info` too shows a total time of say 10 secs for instance but on playing it, it goes on for much more than 10 seconds. Any tools you would recommend for me to debug without having to go through the code? Thank you edit 1: turns out it's `image_view` that I'm running which slows it down. Is this a known problem that image_view doesn't show images at ~7Hz at 3MP?