// Must convert to a real before multiplying by -1
// XMPValidate guarantees there will always be a '/' in this value.
list( $nom, $denom ) = explode( '/', $data['xmp-exif']['GPSAltitude'] );
// Must convert to a real before multiplying by -1
// XMPValidate guarantees there will always be a '/' in this value.
list( $nom, $denom ) = explode( '/', $data['xmp-exif']['GPSAltitude'] );