make pattern file of augmented reality marker (.patt file) in android code

Question

Are there any instructions in Java to get a bitmap of an augmented reality marker and generate a pattern file from it? I mean the pattern files (.patt) that are used in the AR augmented reality library. (This file includes a matrix with 0-255 values.) for example in this online pattern generator we can upload a bitmap and it generates a pattern file. Now, I want to have an instruction in Android code to do the same. I know in ARtoolkit there is a mk_patt class that does that, but it is in C. I want to use it in Android. Thanks a lot.