Media Manager - Adjusting picture size

[drrich]

Media Manager is working and it is possible to view pictures stored on the computer on the HDTV but these pictures are in a reduced size.  There are black bars on all four sides of the picture.  

The pictures are jpeg files and show a 3000 x 2000 pixel count.  Since both of these numbers are well above the dimensions of an HDTV image why aren't these jpeg filling the screen.  

Is there a setting I need to adjust in either Media Manager, on my settop box, or possible within my computer?

Thanks to anyone who can supply information that can fix this  problem.

[matcarl]

Put the STB on an SD channel first, then go into media manager and then the black bars will only be on the sides.