question: public byte [ ] embedData ( byte [ ] msg , String msgFileName , byte [ ] cover , String coverFileName , String stegoFileName ) throws OpenStegoException { BufferedImage image = null ; DctLSBOutputStream os = null ; int imgType = 0 ; try { if ( cover == null ) { image = ImageUtil . generateRandomImage ( ( DCTDataHeader . getMaxHeaderSize ( ) + msg . length ) * 8 * DCT . NJPEG * DCT . NJPEG ) ; } else { image = ImageUtil . byteArrayToImage ( cover , coverFileName ) ; } imgType = image . getType ( ) ; os = new DctLSBOutputStream ( image , msg . length , msgFileName , this . config ) ; os . write ( msg ) ; os . close ( ) ; return ImageUtil . imageToByteArray ( os . getImage ( imgType ) , stegoFileName , this ) ; } catch ( IOException ioEx ) { throw new OpenStegoException ( ioEx ) ; } }
target:  Method to embed the message into the cover data