hiiiieeeee subhajit,
basically if ur thinking to use AT89 series microcontroller then it is not possible to connect the camera its basically these microcontroller are not made to process these things here is a site in which a digital camera is used named c3088
(http://microchips-pic.blogspot.in/2010/01/digital-camera-interface.html)
nso now u can check that out
REGARDS
PYT