To share the image, see the below function.
private void shareImage() {
Intent share = new Intent(Intent.ACTION_SEND);
// If you want to share a png image only, you can do:
// setType("image/png"); OR for jpeg: setType("image/jpeg");
share.setType("image/*");
// Make sure you put example png image named myImage.png in your
// directory
String imagePath = Environment.getExternalStorageDirectory()
+ "/myImage.png";
File imageFileToShare = new File(imagePath);
Uri uri = Uri.fromFile(imageFileToShare);
share.putExtra(Intent.EXTRA_STREAM, uri);
startActivity(Intent.createChooser(share, "Share Image!"));
}