[PhotoStation] - Poor quality diplay with HTTP sharing

[MProject4]

Hello !

I'm trying to share pictures on my QNAP NAS (TS-509, Firmware 4.2.6, PhotoStation 5.2.11).
No problem with the configuration but when I go on the http shared page, the picture quality is really poor compare what I have on the disks.

Is PhotoStation compressing automaticly pictures, even when we put "Original" for Display Photo section in Media Streaming Add-on tool ?
Is there a way/workaround to fix it ?

Thanks a lot for your help !

Regards,
Remy.