How to put text over images in html?

You can create a div with the exact same size as the image.

<div class="imageContainer">Some Text</div>

use the css background-image property to show the image

 .imageContainer {
       width:200px; 
       height:200px; 
       background-image: url(locationoftheimage);
 }

more here

note: this slichtly tampers the semantics of your document. If needed use javascript to inject the div in the place of a real image.