Use the Image ALT Attribute
We all know how important it is to put your targeted keywords in your links and on your relevant pages. Thats why you should always do keyword research first of all.
But what about images? You can't put your text on an image. Search engines can't read text within an image, its just more pixels to them, so how do we describe our images and make use of keyword targeting?
The answer is alternative text, in the from of the ALT attribute. Every image should have an ALT attribute with some descriptive text about the image.
ALT TAGs or ALT Attributes
An Example would be
<img src="i/imagename.jpg" width="100px" height="25px" alt="Search Engine Optimisation" />
This tells the search engines what your image is about. It stands to reason that your page about "seo widgets" would have an image of an "seo widget" on it doesn't it? Of course it does, so make sure the search engines know your page is really about "seo widgets" with an alt attribute, often refered to as an ALT tag.
The SEO Files Recomends
Put your Keywords in the ALT attribute of your images.