Most Content Management Systems (CMS) have tools built in for optimising the use of images for search engines, but they often go unused. The thing to remember is that search engines cannot “read” images. They can only read the descriptions, tags, and titles you give your images.
To start with, image filenames should have a relevant name, ideally with a keyword in it. (More on keywords later.) For example, an image filename of “obam435.jpg” might make sense to you, the website owner, but won’t mean anything to a search engine. “obamastateoftheunionspeech.jpg” is a much more descriptive, and relevant, filename.
All images should have ALT and TITLE attributes defined. This is the image equivalent of the doc title or metadescription for the page. When you insert the image, you may get options to add Title, Alternate Text, Caption and Description. Use appropriate key words and phrases to describe your image - always keeping search engine optimisation in mind.