I have extracted image uri, now I would like to open image with Android's default image viewer. Or even better, user could choose what program to use to open the image. Something like File Explorers offer you if you try to open a file.
Ask myself, answer myself also:
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("content://media/external/images/media/16"))); /** replace with your own uri */
It will also ask what program to use to view the file.