Mechanical conversion from one format to another doesn't defeat copyright protection. If you write a book in English and I translate it into French (a change much more fundamental and much more creative than you're proposing), that doesn't entitle me to publish it without your permission.

The shapes of the glyphs are not protectable. The font file is considered to be a computer program, and is protectable as such. Converting it to a different format doesn't get around copyright any more than compiling a C program does.