Here at Gadget Factory we’ve been thinking about the best way to provide support for the OV7670 Camera Wing that we have. This page we came across provides a treasure trove of information about how the OV7670 camera works.
The OV7670 is a low cost image sensor + DSP that can operate at a maximum of 30 fps and 640 x 480 (“VGA”) resolutions, equivalent to 0.3 Megapixels. The captured image can be pre-processed by the DSP before sending it out. This preprocessing can be configured via the Serial Camera Control Bus (SCCB). You can see the full datasheet here.