Tongue Segmentation Project - Rewrite or modify C code to make it synthesizable to simulate in HLS tools

This is the continuous work from a developer, which he has done the algorithms of tongue segmentation into c code. For our part, we need to use or re-write to make the c code synthesizable to be implemented on HLS design flow and generate into HDL and do the validation on the performances, area, speed. Because from our understanding, the HLS compiler could run simulation, synthesis, export rtl and run the c/rtl-co-simulation and generate the HDL and RTL To run the simulation on HLS compiler, it need a source code and testbench But with the only high level synthesis c code, i don't know how to rewrite or modified to make it synthesizable to simulate in HLS tools