It is a "derivative work" and the same copyright rules would apply to it as would apply to any other derivative work.
http://www.google.com/search?q=derivative+work
Whether the person who runs the conversion program gains any authorship rights in the derivative work would depend on whether the courts think running a conversion program makes the derivative work differ sufficiently from the original. I suspect not because running a conversion program doesn't involve any creative or artistic decision making.
However, I am not a lawyer, and I suggest you consult with one before making any important decisions involving the copyright of such a work.