Manipulating images with Photoshop or a similar program is one things, doing it in a way that actually enhances the essence of a photo is a quite different animal. This particular image avoids the postcard blue sky and creates an atmosphere of wetness. I've never been to Venice (at least not the one in Italy) and cannot comment on how authentic the atmosphere is. Real or not is a very atmospheric picture.
All of Italy is extraordinary...each area different from its neighboring province, but Venice! Venice is as magical as the image you have here! What a supremely beautiful representation you share!! Brava!