A United States Patent ( 19 ) 11 Patent Number : 6 , 157 , 746

Hung-Ju Lee, Robbinsville, both of 5,509,088 4/1996 Robson ................................... 382/233 s s 5,526.299 6/1996 Coifman et al. . 364/807 N.J. 5,673,340 9/1997 Kanda ..................................... 382/250 5,764,805 6/1998 Martucci et al. ....................... 382/238 73 Assignees: Sarnoff Corporation, Princeton, N.J.; 5,781,906 7/1998 Aggarwal et al. ...................... 707/102 Sharp Kabushiki Kaisha, Osaka, Japan FOREIGN PATENT DOCUMENTS