Pictures management

from now pictures take havy spaces on my discourse directory
/uploads/default# du -h --max-depth=1
8.0G ./original
14G ./optimized
22G .

optimized directory is bigger than original, because it contains many different size of the same picture for example.


By the past we have talked about that, I understood disk space is cheaper than processor.

__ My question is __ : if i delete some optimized image, are they generated again when someone view the topic wich include this picture?

For the avatar picture some of them have 21 different pictures, is it not too much ?