How to align an image dead center with bootstrap

Question

I'm using the bootstrap framework and trying to get an image centered horizontally without success..

I've tried various techniques such as splitting the the 12 grid system in 3 equal blocks e.g

<div class="container">
    <div class="row">
      <div class="span4"></div>
      <div class="span4"><img src="logo.png" /></div>
      <div class="span4"></div>
    </div>
</div>

What's the easiest method to get an image centered relative to the page?

Answer 1

Twitter Bootstrap v3.0.3 has a class: center-block

Center content blocks

Set an element to display: block and center via margin. Available as a mixin and class.

Just need to add a class .center-block in the img tag, looks like this

<div class="container">
  <div class="row">
    <div class="span4"></div>
    <div class="span4"><img class="center-block" src="logo.png" /></div>
    <div class="span4"></div>
  </div>
</div>

In Bootstrap already has css style call .center-block

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

You can see a sample from here