FujiFilm S2800HD has a 14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Olympus VR-340 has a 16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the S2800HD and VR-340 sensor size comparison.
FujiFilm S2800HD and Olympus VR-340 have sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since FujiFilm S2800HD has 15% larger pixel area compared to Olympus VR-340, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.