[Dr.Jones]

signature (0000 can be also 0001, i think this mean's more bytes per pixel, 4bytes if 0001 and 3bytes if 0000)

First of all thank you for your help and all information you can share with us.

I presume "bytes per pixel" means the color channels? 3 would then be ordinary RGB and 4 would be RGB+Alpha, right?

Yes.

br.
Dr.Jones