Refere Link: http://www.codeproject.com/KB/GDI-plus/watermark.aspx

Download code: https://skydrive.live.com/?cid=efc0ec2e2cd761ee#!/?cid=efc0ec2e2cd761ee&id=EFC0EC2E2CD761EE%21150

impose one image on another image. it’s also called watermark effect also.