Inner Border or outline in Images Using CSS/HTML
img {
outline: 1px solid white;
outline-offset: -4px;
}
IE9&10 do not support the outline-offset property, but otherwise support is good:
Alternate solution that doesn't require knowing the dimensions of the image:
<div class="ie-container"><img src="" /></div>
div.ie-container {
display: inline-block;
position: relative;
}
div.ie-container:before {
display: block;
content: '';
position: absolute;
top: 4px;
right: 4px;
bottom: 4px;
left: 4px;
border: 1px solid white;
}
img {
vertical-align: middle; /* optional */
}