Second this. Video processing is somewhere I've used fpgas with great success. Embedded systems especially get a huge perf/watt boost when vision processing goes (at least partly) to an FPGA.
Video works really well because its discrete (60fps) and an FPGA just can't hit the clock speeds an asic will. If you already have a semantic clock requirement that is low, streaming works great.
FPGAs have high speed links and can perform thousands of operations in parallel. When you have a huge amount of data to process in real time, an FPGA (or ASIC) is often your only choice.