question: public RpfSubframe decompressSubframe ( int x , int y , RpfSubframe subframe , RpfColortable colortable , RpfViewAttributes viewAttributes ) { boolean isDirectColorModel = ( viewAttributes . colorModel == OMRasterObject . COLORMODEL_DIRECT ) ; if ( subframe == null ) { subframe = new RpfSubframe ( ) ; } if ( colortable == null ) { colortable = this . colortable ; } if ( ! isDirectColorModel ) { if ( DEBUG_RPFDETAIL ) { Debug . output ( "RpfFrame: decompress to byte[]" ) ; } byte [ ] pixels = decompressSubframe ( x , y ) ; subframe . setBitsAndColors ( pixels , colortable . colors ) ; } else { int [ ] pixels = decompressSubframe ( x , y , colortable ) ; subframe . setPixels ( pixels ) ; } return subframe ; }
target:  Decompress a subframe into a cache entry OMRaster (RpfSubframe). The RpfSubframe is returned, too, to emphasize what's happening.