Several SEO methods can be used in tandem with your image to attract as many visitors to your site as possible.

The File Name should contain Keywords
The first, and an often overlooked step, is to ensure that you have used the keyword for the image inside what you have named the file. This is similar to having made sure that the keyword is in your URL; as having the keywords in the names of these files assists search engines in determining relevancy to searches. Use this method with all images, especially those that are more than just simple decoration. It will help your image appear more often in the results by content search, and in a higher place on the results list. Google suggests that website hosts gather the images into a single folder on the website as opposed to having them strewn about the pages.

Select Relevant Images
The most important thing about your image is that it be relevant to the content of your page. Whether explaining something specific, or serving as a layout enhancement; relevancy to your content is the most important aspect of an image. When an image has been optimized for a search engine, cohesiveness is the key factor that produces results. Having an image on the page that does not tie in with the site is something to consciously avoid. Presenting attractive and relevant images can critically impact your potential customer base via the content. Images attract, and maintain the attention of your visitors, and should serve as an enhancement to the content provided to keep a person engaged. As tempting as it is to have large flashy images, avoid this pitfall. Avoid having a large quantity of images on the site. This can clog the load time of the site, and some visitors will click out of a web-page that doesn't load quickly.

Use Alt Text or Text Tags
Images on the page need to have a title as well as an alternative text tag, ALT Text, to describe it. While the qualities of the image should be able to be extracted from the content of the page, having these two pieces of information can serve a reverse purpose. Studies show casual surfers are drawn to the images of a page when first reaching it. Having an informative title coupled with quality descriptive text can make those who are just surfing interested enough to read the rest of the page. If the image is a navigational tool that connects to another page, it is important to have the descriptive text reflect the content of the other page ensuring browsers that the link will lead to the content they want to view.

Anchor Text
Having the complete information of an image attached to the image, known as anchor text, helps with the automation aspect of a search engine as it allows for a quicker indexing of the image in their database. Having a SEO image is beneficial as the image will show up in a search engine when only the only search criterion is the keyword.
By Eric T Callahan