question: public static byte [ ] flattenBitmap ( Bitmap bitmap ) { int size = bitmap . getWidth ( ) * bitmap . getHeight ( ) * 4 ; ByteArrayOutputStream out = new ByteArrayOutputStream ( size ) ; try { bitmap . compress ( Bitmap . CompressFormat . PNG , 100 , out ) ; out . flush ( ) ; out . close ( ) ; return out . toByteArray ( ) ; } catch ( IOException e ) { Log . w ( TAG , "Could not write bitmap" ) ; return null ; } }
target:  Compresses the bitmap to a byte array for serialization.