Image Optimization is a piece in SEO puzzle which many webmasters do not give proper attention.
Here are some tips for Image Optimization
Use small file size images
Try to make your images as small as possible in file size. Large size images can affect your website’s performance in different ways. Your page’s file size will increase affecting SEO negatively. Also many visitors will not wait too long for the images to load on the page.
Use keywords in image names
When naming images try to use your keywords, instead of using picture123, you can use Daily-SEO-banner etc.
Use hyphens in image names
The idea is similar to the one we’ve talked about in Using Hyphens in URL article. Name your images accordingly. Good naming example:
Washington-DC-Building.jpg Empire-State-Building.gif SEO-logo.gif etc.
Use alt tags for image optimization
Always use Alt Tags. Try to have a brief description of the image if possible, by using your page’s keywords. Here’s an example of Alt Tag Usage
<IMG SRC="/images/insider-seo-book.jpg" HEIGHT=327 WIDTH=291 ALT="Insider’s Guide to SEO">
By optimizing your images you might get some decent traffic from Google Images and other image related search engines.
Here’s a recent discussion about Optimizing Images at DigitalPoint Forums.