Silicon Image Inc . said Monday its president and CEO, Steve Tirado, resigned. Sunnyvale-based Silicon Image (NASDAQ:SIMG) said its CFO , Hal Covert, will also take over the COO and president roles. The company did not give a reason for Tirado's departure, but said it has retained an executive search firm to find a new CEO. Covert joined Silicon Image from Openwave Systems Inc. in 2007, and has more than 30-years of management experience at technology and telecommunications companies .