Changeset 6313 for trunk/wp-admin/includes/image.php

Timestamp:

11/05/2007 12:01:26 AM (17 years ago)

Author:

ryan

Message:

Extract and save image metadata. Props tellyworth. fixes #5162

File:

• trunk/wp-admin/includes/image.php (modified) (2 diffs)

trunk/wp-admin/includes/image.php

@@ -153 +153 @@
                 $metadata['thumb'] = basename($thumb);
         }
+        
+        // fetch additional metadata from exif/iptc
+        $image_meta = wp_read_image_metadata( $file );
+        if ($image_meta)
+            $metadata['image_meta'] = $image_meta;
+
     }
     return apply_filters( 'wp_generate_attachment_metadata', $metadata );
@@ -223 +229 @@
 }
 
+// convert a fraction string to a decimal
+function wp_exif_frac2dec($str) {
+    @list( $n, $d ) = explode( '/', $str );
+    if ( !empty($d) )
+        return $n / $d;
+    return $str;
+}
+
+// convert the exif date format to a unix timestamp
+function wp_exif_date2ts($str) {
+    // seriously, who formats a date like 'YYYY:MM:DD hh:mm:ss'?
+    @list( $date, $time ) = explode( ' ', trim($str) );
+    @list( $y, $m, $d ) = explode( ':', $date );
+
+    return strtotime( "{$y}-{$m}-{$d} {$time}" );
+}
+
+// get extended image metadata, exif or iptc as available
+function wp_read_image_metadata( $file ) {
+    if ( !file_exists( $file ) )
+        return false;
+
+    // exif contains a bunch of data we'll probably never need formatted in ways that are difficult to use.
+    // We'll normalize it and just extract the fields that are likely to be useful.  Fractions and numbers
+    // are converted to floats, dates to unix timestamps, and everything else to strings.
+    $meta = array(
+        'aperture' => 0,
+        'credit' => '',
+        'camera' => '',
+        'caption' => '',
+        'created_timestamp' => 0,
+        'copyright' => '',
+        'focal_length' => 0,
+        'iso' => 0,
+        'shutter_speed' => 0,
+        'title' => '',
+    );
+
+    // read iptc first, since it might contain data not available in exif such as caption, description etc
+    if ( is_callable('iptcparse') ) {
+        getimagesize($file, $info);
+        if ( !empty($info['APP13']) ) {
+            $iptc = iptcparse($info['APP13']);
+            if ( !empty($iptc['2#110'][0]) ) // credit
+                $meta['credit'] = trim( $iptc['2#110'][0] );
+            elseif ( !empty($iptc['2#080'][0]) ) // byline
+                $meta['credit'] = trim( $iptc['2#080'][0] );
+            if ( !empty($iptc['2#055'][0]) and !empty($iptc['2#060'][0]) ) // created datee and time
+                $meta['created_timestamp'] = strtotime($iptc['2#055'][0] . ' ' . $iptc['2#060'][0]);
+            if ( !empty($iptc['2#120'][0]) ) // caption
+                $meta['caption'] = trim( $iptc['2#120'][0] );
+            if ( !empty($iptc['2#116'][0]) ) // copyright
+                $meta['copyright'] = trim( $iptc['2#116'][0] );
+            if ( !empty($iptc['2#005'][0]) ) // title
+                $meta['title'] = trim( $iptc['2#005'][0] );
+         }
+    }
+
+    // fetch additional info from exif if available
+    if ( is_callable('exif_read_data') ) {
+        $exif = exif_read_data( $file );
+        if (!empty($exif['FNumber']))
+            $meta['aperture'] = round( wp_exif_frac2dec( $exif['FNumber'] ), 2 );
+        if (!empty($exif['Model']))
+            $meta['camera'] = trim( $exif['Model'] );
+        if (!empty($exif['DateTimeDigitized']))
+            $meta['created_timestamp'] = wp_exif_date2ts($exif['DateTimeDigitized']);
+        if (!empty($exif['FocalLength']))
+            $meta['focal_length'] = wp_exif_frac2dec( $exif['FocalLength'] );
+        if (!empty($exif['ISOSpeedRatings']))
+            $meta['iso'] = $exif['ISOSpeedRatings'];
+        if (!empty($exif['ExposureTime']))
+            $meta['shutter_speed'] = wp_exif_frac2dec( $exif['ExposureTime'] );
+    }
+    // FIXME: try other exif libraries if available
+
+    return apply_filters( 'wp_read_image_metadata', $meta, $file );
+
+}
+
 ?>