It is possible to see big drops in traffic from Google Images if you modify the file names of your images or change the images in some way.

A comparison of the four major search engines shows Yahoo! has the most interesting results with a mix of established and fresh content.

While you would think Google would use what it’s learned in ranking images for image search when it presents images in it’s “Universal Search” - that’s not the case at all. Bottom line - image search results are far better than Universal Search.

When crafting your robots.txt file, don’t forget that the search engines have specialized spiders that crawl for image search. These spiders need to see not only the image file, but the page that it is used on.

Image search is a valuable tool for driving traffic to your site, but you have to practice certain good habits so the search engines understand the images on your site.