What we did—and what I assume you mean by "generate"—is tweak values using the NI vision assistant, then write equivalent code in Java. (Using the assistant to write C code and wrapping that for use in Java is very nontrivial.)
Have you installed the latest NetBeans FRC plugin updates? The most recent one ports several more NI Vision functions to Java, including particle filters and convex hull operations. Both of those are methods of the
BinaryImage class.
With one of the plugin updates come new examples of how to use these new vision features in Java. The examples are also available on
FIRST Forge. Several teams (including 125) post their code on
GitHub, so if you're in need of inspiration there's plenty of material out there.