PHPで Photo Sphere XMP Metadataをパース

parse-xmp.php

<?php

$ns = 'http://ns.google.com/photos/1.0/panorama/'
$image = '/path/to/image.jpg';

$content = file_get_contents( $image );
$xmp_data_start = strpos( $content, '<x:xmpmeta' );
$xmp_data_end   = strpos( $content, '</x:xmpmeta>' );
$xmp_length     = $xmp_data_end - $xmp_data_start;

if ( $xmp_length ) {
	$xmp_data = substr( $content, $xmp_data_start, $xmp_length + 12 );
	$xmp = simplexml_load_string( $xmp_data );
	$xmp = $xmp->children( "http://www.w3.org/1999/02/22-rdf-syntax-ns#" );
	$xmp = $xmp->RDF->Description;
	if ( "TRUE" === strtoupper( (string) $xmp->attributes( $ns )->UsePanoramaViewer ) ) {
		return true;
	} elseif ( "TRUE" === strtoupper( (string) $xmp->children( $ns )->UsePanoramaViewer ) ) {
		return true;
	}
}