Nice theme Ste-phan!

As this seems to be the only written technical limitation, i need to ask if editing is allowed and if yes to what extend?
Last time i resized the image and after submission the question arised within myself if that is already bending of some unwritten rule, e.g. "no editing allowed whatsoever"?
What about tempering with levels or contrast?
Is HDR allowed but doing it manually buy cutting into layers is not?
So many questionmarks, i guess there is a simple answer