<img src="{dede:field.litpic /}"> 

{dede:field.litpic runphp="yes"}if (@me!=''){@me= "<img src='".@me."'/>";}{/dede:field.litpic} 

[field:array runphp='yes']@me = (strpos(@me['litpic'],'defaultpic') ? "" : "<a href='{@me['arcurl']}'><img src=\"{@me['litpic']}\" alt=\"{@me['title']}\"/></a>"); [/field:array]