I have received a request for supporting GPS in PNG file format.
[Github] piwigo-openstreetmap issue #14

Even so there no real standard. it is possible to store EXIF GPS metadata in PNG file.
PHP http://www.php.net/manual/en/function.e … d-data.php only read EXIF data for TIFF and JPEG.

However imagick.getimageproperties http://www.php.net/manual/en/imagick.ge … erties.php fetch correctly the EXIF GPS info in PNG format.
I was able to create fast patch to read them in PHP.

Maybe it is worth taking a look and maybe to be include in the PWG core.