9. The method defined in claim 1 wherein the file comprises a JPM file, and wherein extracting one or more features comprises generating a bit allocation map for the JPM file by: reading structural information boxes from the JPM file; selecting a resolution; determining bit allocations for the selected resolution for the bit allocation map in regions affected by mask and image codestreams of every object on each page.
9. The method defined in claim 1 wherein the file comprises a JPM file, and wherein extracting one or more features comprises generating a bit allocation map for the JPM file by: reading structural information boxes from the JPM file; selecting a resolution; determining bit allocations for the selected resolution for the bit allocation map in regions affected by mask and image codestreams of every object on each page. 11. The method defined in claim 9 wherein extracting one or more features further comprises classifying objects based on compression type.