Prepare your site images for google image search indexing

I'm trying to understand how can I do to let my site be reachable from google image search spiders. I like how last.fm solution, and I thought to use a technique like his staff do to let google find artists images on their pages.

When I'm looking for an artist and I search it on google image search, as often as not I find an image from last.fm artists page, I make an example:

If I search the band Pure Reason Revolution It brings me here, the artist's image page

http://www.last.fm/music/Pure+Reason+Revolution/+images/4284073

No开发者_StackOverflow中文版w if I take a look to the image file, i can see it's named:

http://userserve-ak.last.fm/serve/500/4284073/Pure+Reason+Revolution+4.jpg

so if I try to understand how the service works I can try to say:

http://userserve-ak.last.fm/serve/ the server who serve the images

500/ the selected size for the image

4284073/ the image id for database

Pure+Reason+Revolution+4.jpg the image name

I thought it's difficult to think the real filename for the image is Pure+Reason+Revolution+4.jpg for image overwrite problems when an user upload it, in facts, if I digit:

http://userserve-ak.last.fm/serve/500/4284073.jpg

I probably find the real image location and filename

I see this can be done with mod_rewrite engine, but with this tecnique, will the image be highly reachable from search engines and easily archived?

My question is, does exist some guide or tutorial to approach on this kind of tecniques, or something similar?

In my opinion, the best resource for your question is Google itself.

One of the guides targets at google images search and provides some guidelines:

• Don't embed text inside images
• Tell us as much as you can about the image
  • Give your images detailed, informative filenames
  • Create great alt text
  • Anchor text
• Provide good context for your image
• Think about the best ways to protect your images
• Create a great user experience

Source: Images - Webmaster Tools Help.

As for last.fm, one of the suggestions is:

Give your images detailed, informative filenames

The filename can give Google clues about the subject matter of the image. Try to make your filename a good description of the subject matter of the image. For example, my-new-black-kitten.jpg is a lot more informative than IMG00023.JPG. Descriptive filenames can also be useful to users: If we're unable to find suitable text in the page on which we found the image, we'll use the filename as the image's snippet in our search results.

So yes, last.fm uses mod_rewrite to give informative filename, which google likes.

There are few more guides out there. None of them is formal, but they can help you anyway:

http://www.tareeinternet.com/forum/seo/236-optimizing-google-image-search.html

http://www.doshdosh.com/how-to-optimize-for-google-images-for-more-traffic/

http://creativebits.org/webdev/optimize_your_site_for_google_image_search

http://www.pearsonified.com/2007/01/get_53_percent_more_searches_with_one_tweak.php

The article pointed out by Tim covers most of it but I'd like to add that the title attribute on <img> tags is important too (but don't abuse it!).

To sum up:

1. Name your files well. apple.jpg is better SEO wise than PIC2346.jpg. For spaces in filenames use a dash (-) and not an underscore (_). See Dashes vs. underscores for more info.
2. Alyays fill up the alt attibute. Keep in mind that most screen readers for blind people will read this tag.
3. Fill the title attribute when usefull. Use a short statement describing the image. Not a whole paragraph!
4. The context of the image (what is the content around it) is very important too. If the image fits the surrounding contents it will give you more SEO "points".