[Toxaris]

Originally Posted by RbnJrg

Images are not the same as text. It's possible that ereaders will display images centered using the text-align property but it’s not a good idea. Instead, you should specify that the image is a block element. Then you can center it as you would a block:

img.centered {
      display: block;
      margin-left: auto;
      margin-right: auto;
}

and

<div class="centre">
       <img class="centered" alt="valid html, css, and epub" src="../Images/valid.png" width="25%" />
</div>

I think that should work on iBooks

Regards
Rubén

This would not work on the majority of the readers out there. The auto value is converted to 0 for margins on those. That is not even a mistake, the specs allow that.

In iBooks it could work.