1、 BitMap  to   inputStream：
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
      InputStream isBm = new ByteArrayInputStream(baos .toByteArray());
 
2、BitMap  to   byte[]：
     Bitmap defaultIcon = BitmapFactory.decodeStream(in);
     ByteArrayOutputStream stream = new ByteArrayOutputStream();
     defaultIcon.compress(Bitmap.CompressFormat.JPEG, 100, stream);
     byte[] bitmapdata = stream.toByteArray();
 3、Drawable  to   byte[]：
      Drawable d; // the drawable (Captain Obvious, to the rescue!!!)
      Bitmap bitmap = ((BitmapDrawable)d).getBitmap();
      ByteArrayOutputStream stream = new ByteArrayOutputStream();
      defaultIcon.compress(Bitmap.CompressFormat.JPEG, 100, bitmap);
      byte[] bitmapdata = stream.toByteArray();
 
4、byte[]  to  Bitmap ：
     Bitmap bitmap =BitmapFactory.decodeByteArray(byte[], 0,byte[].length);

BitMap、Drawable、inputStream及byte[] 互转