Try using some of the FPGA I/O pins to interface directly to the on-camera CMOS sensor chip. An example can be found here:

http://hamsterworks.co.nz/mediawiki/index.php/OV7670_camera

S3E kit has hirose connector, you can use digilent's vdec board and analogic camera, you can find projects in digilent's web site, other option is to use a cmos sensor and a direct connection with FPGA, you must implement the sensor protocol for . In both cases you must implement in hardware the digital architecture for adquiring, storing and processing image.

How to add CCD camera to spartan 3E kit