Picasa Web Albums
prevents hotlinking directly to photos, and only allows certain sizes to be hot-linked.
For about a year now, I have only been able to successfully hotlink using size 288.
But then today I looked at Sam’s post at http://sam.davyson.com/weblog/hotlinking-picasa-web-albums-images/ and noticed the 576 size works for me in both Firefox and Internet Explorer (with referer and agent sending enabled).
That prompted me to make this post, with a collection of various hotlinks to picasa web photos (from my private albums, so I know noone could have previously viewed the album). If you have the time, please leave a comment telling me (and anyone who might read this) which hotlinks work/don’t work.
Note: Any size which has previously been viewed using the Picasa Web interface (not hotlinked) in the current browser sessions is then viewable as a hotlinked image (only in that browser session). So you need to consider that when testing hotlinked images.
Update After a few weeks I can confirm the following hotlinks definitely work: http://lh6.google.com/james.laugesen/ReV6ymoCUZI/AAAAAAAAFvk/bk1mXJZJyfk/s288/050620%20055.jpg http://lh3.google.com/james.laugesen/ReQ6rGoCSOI/AAAAAAAAFew/PcjrtZT6Dwk/s576/capture2.JPG http://lh5.google.com/james.laugesen/ReQ4-moCQrI/AAAAAAAAFTQ/vIopYtnhZnY/s640/Image023.jpg http://lh4.google.com/james.laugesen/ReQ4nWoCQhI/AAAAAAAAFSM/K0T330QkNU0/s800/boat.jpg
So, it appears that Google have allowed hotlinking to any size now.
UPDATE - 10th April 2008 http://www.jl.sg/articles/2008/04/09/picasa-web-album-hotlinking-update