What criteria does G use to gather images?

[oaktown]

What criteria decide which images G archives? I was just curious and haven't indentified a pattern. Any ideas?

Thanks in advanvce.

[tedster]

Can't say I've nailed this down, either. A lot of it has to do with there being a clear signal of some sort that helps Google associate the image with keywords. But as with any algorithm, they don't always get this right. Possible signals might include keywords in the image's file name or in the page title (this is where they seem to mess up at times).

[joergnw10]

On one of our sites google uses the h1 / h2 tags. The majority of images now have the product price as title.

[oaktown]

Thanks guys, but I guess I'm really asking what kind of bait to put out for "GoogleBot-Image". Any suggestions? Thanks in advance.

[texasville]

My images rank well in google, unlike my site. It is probably because they are all labeled(example:<img border="0" src="widgets/green-long-widget-5x8-003.jpg" alt="5x8 green widget" width="100" height="75") so that is easy for the bot to interpret what it is.

[fred9989]

No, I don't think it is just image labelling in alt tgs (or even primarily this).
There are some hilariously bad interpretations of some of the pictures on some of my sites in Google image search - and they have been there for years under these crazily irrelevant search terms.
Yet on other sites the picture targeting is spot on - but this only applies to very narrowly themed sites with all the images labelled exactly the same in alt tags, and where the alt tags match the keywords of title, description and headings in the html.
On less tightly themed sites, Google seems to have selected the pictures for a particular image search term by taking random words and random images and associating them!
Obviously that isn't the case, but it can look like a bot of a joke.
Rod

[Petra Kaiser]

logical keyword stuffing seems to work fine

(example:<img border="0" src="widgets/green-long-widget-5x8-003.jpg" alt="5x8 green widget" width="100" height="75") + <p> 5x8 green widget

on a search for 5x8 green widget gives as result the picture itself, the picture above and the picture below side by side, pictures must have at least one identical word in alt and p

[Oliver Henniges]

The way google identifies images is really amazing. I receive more visitors from google-images than any other search-engine meanwhile.

Though I yet don't use it myself, I'suppose there is definitely one important way to boost rankings in google images: namely the long-desc-tag according to the web-content-accessibility- guidelines.