What does the rasterised data look like? That utility you linked to was designed to be used with a particular lcd library. In general there are not many similar libraries for led displays because there are so many different controller designs. Many do not have a controller as such and use the Arduino for multiplexing.
But once the data is rasterised, it might be in a suitable format to be further manipulated into something you could use. What design is your led matrix controller?