Exercise 4.6 Action Server

Hello everyone,
I am trying to understand the code in the Python file (see the solution) at the exercise 4.6. When i launch the launch file, it work well, but at one point i dont really understand , what is going on here in the code lines (see on the picture). Thanks for your help


I don’t think there’s any problem there. Obviously there’s some extra delay between receiving image n.3 and image n.4, and during this time those lines are displayed 2 extra times compared with other images received.

If you run the program again, you might have a different output (Could you try and let us know?). If the output remains the same in several runs, then there might be some permanent issue with image n.4. In any case, there’s no problem with this at all because all images are not created equal :slight_smile:.