ByteArray ba; // Some value is assigned here
Bitmap bitmap = BitmapFactory.decodeByteArray(ba, 0, ba.length);

ByteArray ba; // Some value is assigned here
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 4; //or whatever value
Bitmap bitmap = BitmapFactory.decodeByteArray(ba, 0, ba.length, options);