How can count amount peak of graph ?

[Jens Noriʇzsɔɥ]

You could have a look at the “Motion Stopwatch” that has likely most of the functionality implemented (particularly, check the “many” tab). Personally, I would start with it and kick anything out that looks unneeded – and learn a lot doing that because Sebastian has included some magic…

Have you tried a rate of 100 Hz like in the original graph? It could be that you just miss the full height with a lower rate.