Inserting an FPGA on a MIPI camera lane
Using MIPI with FPGA's seems to be a recurring question.
Xilinx have an application note which tells how you can connect a MIPI device to their chips: Here. 

As to extracting the MIPI data, I think you have to pay for their solution. But it is possible to build your own. (At least for an experienced HDL programmer).

Handling the 'MIPI stream' should not require much FPGA resources. This in contrast to image processing. A simple BTC for 8x8 blocks can easily use up most of the FPGA memory.