Implement more OpenCV functions/modules and submit a PR request.
Before submitting a PR, make sure you have formatted both C/C++ code and Rust code, otherwise Travis will complain.
You have to have installed clang-format. You can install it as part of full llvm toolchain (download link) to make formatting happen. On mac you can use brew install clang-format.
When you're done run setup_hooks.sh. That will enable automatic source code formatting on commit.