Background images and SEO

Question

i have some background images on my site defined in css

due to some CSS3 effects i cant change the background to a  normal <img> tag.

• Putting text into the <a> tag and then hiding it with CSS with text-indent: -9999em
• Only put a title attribute on the tag with the text in it
• Placing a transparent in the tag with the same title as your tag
• Leave it as I have in my example and building up a so called Image Sitemap in a XML file

these  are the solutions i came up with can you suggest me which ones better 

Answer 1

the thing you can do to overcome this is to write good alt image tags and describe the images in the best ways
<img src="myimage.png" alt="Dog running in front of Redwood Trees"></img>
take this as an example for the alt image tags mentioned
and keep in mind that the images doesnt play a very important role in the seo of your site