Uploading picture..what with the artifacts?

I uploaded some pictures in my previous post but...what? The quality became somewhat artifacts-ish. Why? I surf around and found this. Might just give it a try...experiment..experiment..

And I upload these pictures in Picasa web album first and used the site link for these pictures.. Now let see the result..

GIF format

PNG format

JPEG format (notice the artifacts?)

Hm..any difference? Clearly the GIF and PNG format are better than JPEG.
Hoho..I just found out something new (or maybe I'm outdated). Now I can upload pictures without degrading the original quality..ok, it still degrade the quality but not too bad I would say..

Between GIF and PNG, I prefer GIF since the size is not to big. Upload faster than PNG (but PNG does look better). For detail picture, PNG is better I guess. But if it's just for normal eye candy, GIF is the better choice. JPEG? Just bad..and I'm a bit surprise with the end result..maybe it'll work on different pictures..who knows..

Hope someone with a better knowledge can shed some light..