I found the option again i was looking for $conf['enable_formats'], however there is very little information about it, so im not realy sure how its supposed to work :)

I enabled it and add png to the $conf['format_ext'], which didnt do anything (at least as far as i can see). I have added png back to $conf['picture_ext'] list, and to me it looks like im back where i started. (A lot of untagged png in my Albums, alongside there tagged .jpg versions).

Again, my goal is to sort of hide the pngs, since i do want to keep them  in the same directory, but not have them show up in my Albums. (Again, im using the ftp import function to copy my whole folder structure onto my server).

Anything i have missed?

['file_ext'] is a merged array out of ['picture_ext'] and a list of additional formats ('tiff', 'tif', 'mpg','zip','avi','mp3','ogg','pdf') by default.

So to remove png from the ['file_ext'] i have to remove it from ['picture_ext'] dont I?

If i do that they still show up as Question-marks, both in the Gallery and the admin Menu.

So this should work if i dint want pngs in my Galleries:

$conf['picture_ext'] = array('jpg','jpeg','gif');

$conf['file_ext'] = array_merge(
  $conf['picture_ext'],
  array('tiff', 'tif', 'mpg','zip','avi','mp3','ogg','pdf')
  );

After i made the changes i ran i sync. I did enable the sync for already existing entries etc.

And know it is working!

For some reason i had to include "$conf['file_ext']" part aswell, even tho i didnt change anything in there.

Thanks a lot for your help :)

The expression $conf['file_ext'] = array_merge($conf['file_ext'], ...) had already been evaluated before $conf['picture_ext'] was modified, so you have to set it again to override the default settings.