If I check the gallery indexed photos in Google Images ( site:flapane DOT com SLASH gallery ), I notice that there are just a few pics (normal_$nameofthefile.jpg) and hundreds of useless thumbs (thumb_$nameofthefile.jpg).
I wonder why Googlebot-Image indexed only a few images, and why it indexed a lot of small thumbnails. I have no robots.txt rules for Googlebot-Image, but I wonder if I'd better adding:
User-Agent: Googlebot-Image
Disallow: /gallery/thumbnails.php?*
As a sidenote, my robots.txt already contains:
User-Agent: *
Allow: /
Disallow: /gallery/addfav.php?*
Disallow: /gallery/login.php?*
Disallow: /gallery/thumbnails.php?album=*slideshow
I've just put this in robots.txt.
User-agent: Googlebot-Image
Disallow: /gallery/albums/*/thumb_*.jpg$
I'll check the results in the next days/weeks.
It seems to work, as far as GWT is concerned.
Uhm, it looks like after three weeks the thumbs are all still there. In theory, the trick should work.
It's strange, because Google bots are usually waaaay faster than Bing ones.