As my knowledge of specific CMOS cameras is limited (I sort of know a little about many things, but no actaul experience here) I googled a bit. Found some references to various projects and a datasheet for a specific device.
CMOS Camera Module - 640x480 - SparkFun Electronics - cheap module, sparkfun have a forum for all their products, and the projects people use them for. No doubt you'll find some great interface info here, albeit probably for 'still' images.
**broken link removed** (my favourite site)
https://www.electro-tech-online.com/custompdfs/2011/01/xapp390.pdf (for raw digital elements)
Digital Project -- Digital Camera Interface
https://www.electro-tech-online.com/custompdfs/2011/01/ov6620DSLFPDF.pdf - typical datasheet for B/W basic CMOS module.
I was quite surprised to se that even a relatively low resolution CMOS camera has a lot of on-board electronics. With most camera functions controlled digitally via a simple I2C interface, and it has on board analogue to digital conversion. So it actually outputs a standard digital YUV interface.
Do you have a part no. for the sort of device you were looking at? I imagine it has similar on-board analogue/digital processing for a standard output. For an 'intraoral' camera, of course the camera element itself has to be small, as well as any interface circuitry to condition the signals (and to reduce the number of connections needed - so you don't have a massive fat cable connected to it) to a 'box', which could then contain any larger devices for heavy DSP.
I haven't seen any camera modules which can output a simple RGB analogue signal, which would reduce your connection count considerably, and push the complexity into your external 'box'. But, if it has a 24-bit RGB/YUV output, there are some LVDS serialiser IC's which can reduce these 24 lines to just 3. It is a question of how you partition the design between the hand held device, and the external 'box'.
Please explain further on what digital signal processing you require. If you simply wish to 'display' the image, then little DSP will be required, and some specific non-programmable IC's may do the job. If you want something like image recognition, on screen display etc.. then I imagine even a basic DSP could handle it.
Sorry if I'm probing here, and asking too much about your project, but there are many ways to do things, so the more specific the problem, the more specific the solution.
BT