I got it work.
@foreach (var mediaID in mediaID1)
{
var media = Umbraco.TypedMedia(mediaID);
if (media != null)
{
int width = media.GetPropertyValue<int>("umbracoWidth");
int height = media.GetPropertyValue<int>("umbracoHeight");
if (@width < @height)
{
<div class="photo w2">
<a href="@media.Url()" rel="shadowbox[gallery]"><img class="small-image" src="@media.Url()" /></a>
</div>
}
else
{
<div class="photo">
<a href="@media.Url()" rel="shadowbox[gallery]"><img class="small-image" src="@media.Url()" /></a>
</div>
}
}
}