There is some changes in order to get the Publishing url from an image, here is my code. This is Server Side Code.
var imagemUrl = item["YourImageFieldName"].ToString().Substring(item["YourImageFieldName"].ToString().IndexOf("src=", StringComparison.Ordinal) + 5,
item["YourImageFieldName"].ToString().IndexOf("style=", StringComparison.Ordinal) - (
item["YourImageFieldName"].ToString().IndexOf("src=", StringComparison.Ordinal) + 7));