You can ask almost anyone on the Photo forum here and they will tell you the Canon SD400 especially since it has the Digic II processor as well.
The image quality from the Sony T7... let's just say, it isn't great. The only thing it offers, as a lot of people like and wouldn't mind sacrificing other qualities, is its slimness and 2.5" LCD screen.
Canon is your pick.
And cheaper memory card as well!