machaon on "Picture maximum dimension"

Hello!

I have come across with the surprising feature, uploaded images with large dimensions (w >~ 3100px, h >~ 2100px) will not be processed to make thumbs nor displayed in album except for the original view option. Whereas no filesize limits were identified at the stage.

I wonder if these limits are set somewhere in zenphoto or it's gd-lib limitations?

Thanks!