Height and width attributes missing for images

The <media:content> field formatter is not adding some field_type specific attributes. In my case I'm missing width and height. Looking at the code I think I the reason is we check for $item['type'] instead of $field['type'] before adding the field type specific attributes.

Current output

<media:content 
   url="[img uri]"
   fileSize="10093"
   type="image/png"
   medium="image" />

Expected output

<media:content 
   url="[img uri]"
   fileSize="10093"
   type="image/png"
   width="100"
   height="100"
   medium="image" />