Lubuntu 16.04 (64), wxphp-gtk2 (wxphp-3.0.2.0-gtk2-amd64)

I have a wxphp script that picks a JPG image file, loads it, displays the image and its EXIF data.
It relies on PHP's function exif_read_data() to parse the stuff and put it into an array(array()).
That needs the PHP extensions mbstring.so and exif.so

When I run it, it can't find function exif_read_data(). When I put a
print phpinfo();
in the script, it seems to show mbstring is enabled in there, but not exif.
So I need to edit php.ini , but since it is bundled in wxphp-gtk2, I don't think I can get at it to change it.
And it seems that's not one of the things you can change with:
ini_set('extension', "exif.so");
I guess that makes sense - if you had exif.so in the bundle, you would have enabled it.

So is there a way around this,
or can I ask you nicely to rebuild the package with exif support, please?

<?php   // run with wxphp-gtk2
$file = "/path/to/image.jpg";
$exiftags = exif_read_data($file, 0, true);
// var_dump($exiftags);    // some binary stuff in here
print "$file: FileDateTime: ".$exiftags['FILE']['FileDateTime']."\n";   // integer
print "$file: DateTime: ".$exiftags['IFD0']['DateTime']."\n";           // formatted string
?>