Thanks a lot for suggestion. It is indeed the problem you have pointed out. If I rotate an image before
putting it into the gallery it is shown properly.

I did not manage to update manually the piwigo data-base. After proper log in, using mysql tool, I
tried to execute command:
> UPDATE **_images SET rotation=0 WHERE rotation=*;
However, the outcome is:
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '**_images SET rotation=0 WHERE rotation=*' at line 1

Looking through the mysql manual I did not managed to figure out what I am doing wrong.

I would be very grateful for any suggestion.

myroslav wrote:

I am setting up Piwigo on my home server, driven by Raspberry Pi (low computing resources). It takes ages to generate thumbnails and other sizes of photographs directly on the server. Therefore, I made
a shell script, which generates all required sizes of index images, and copy them to the server, to folder ~/_data/i/galleries/.... .

What works:
- the thumbnails are recognised and displayed properly.
- landscape photos of different sizes are displayed properly

The problem
- portrait photos are displayed as they would be landscape (stretched in horizontal direction)

Technically, all my photographs are stored as landscape with a proper angle tag. When I am
generating thumbnails, and other smaller-size previews, I am rotating them, and erasing "angle" tag
(as piwigo does).

Does piwigo writes something to the DB while generating thumbnails?
How can I tell piwigo that preview images are in the portrait orientation?

Thank you for your response!

Hey, do you think you could share the script? I am interested in pre-genereting my thumbnails too.

as you can see here http://piwigo.org/dev/browser/trunk/i.php that's not the case
http://piwigo.org/dev/browser/trunk/i.php#L338 the script check the Last Modif Time of the original picture and the resized pictures

:) Have a good day