Auto Center and Keep Aspect Ratio of Image in Div - css

Question

I m trying to center an image in a div while keeping the aspect ratio - I m using this code but somehow its not aligning the item in the center (top/bottom center). If possible using only CSS.
The size of the image is not known since its using max widths!
JSfiddle: http://jsfiddle.net/L41wpza6/2/
#imageHolder {
width: 400px;
height: 400px;
line-height: 400px;
background-color:#CCCCCC;
}
#imageHolder img {
max-width: 100%;
max-height:100%;
display: block;
margin: 0 auto;
vertical-align: middle;
}
Any help is appreciated! I am not sure what I am missing to make this work.

Answer 1

JSFiddle - DEMO
You should use display: inline-block; to #imageHolder img to vertical-align middle.
CSS display inline-block property allows elements to flow like inline elements but respect properties, such as width, like block elements and you can use display Inline-block to set vertical-align middle.
HTML:
<div id="imageHolder">
<img src="http://www.discoverjb.com/wp-content/uploads/2014/07/IMG_1399.jpg">
</div>
CSS:
#imageHolder {
width: 400px;
height: 400px;
line-height: 400px;
background-color:#CCCCCC;
}
#imageHolder img {
max-width: 100%;
max-height:100%;
display: inline-block; /* Instead of display: block; */
margin: 0 auto;
vertical-align: middle;
}

Answer 2

for one looking for horizontally center.
Solution of #sibbl worked, but there is still some pixels on the top of image in horizontal case.
I have imporoved #Anoymous code
HTML:
<div class="imageHolder">
<img src="http://lorempixel.com/g/800/400">
</div>
<div class="imageHolder">
<img src="http://lorempixel.com/g/800/800">
</div>
<div class="imageHolder">
<img src="http://lorempixel.com/g/400/800">
</div>
CSS:
.imageHolder {
width: 300px;
height: 300px;
background-color:#CCCCCC;
margin:10px;
display:inline-block;
float:left;
position:relative;
}
.imageHolder img {
max-width: 100%;
max-height:100%;
margin: auto;
position:absolute;
top:0;
left:0;
right:0;
bottom:0;
}
JSFiddle - DEMO