/**
 * Extracts image metadata from the image specified by its path.
 * 
 * @return structured array with all available metadata
 */
public function get_meta_by_path( $name, $tmp_name = NULL ) {

    if ( !$tmp_name ) {
        $tmp_name = $name;
    }

    $this->metadata = array();

    // extract metadata from file
    //  the $meta variable will be populated with it
    $size = getimagesize( $tmp_name, $meta );

    // extract pathinfo and merge with size
    $this->metadata['Image'] = array_merge( $size, pathinfo( $name ) );

    // remove index 'dirname'
    unset($this->metadata['Image']['dirname']);

    // parse iptc
    //  IPTC is stored in the APP13 key of the extracted metadata
    $iptc = iptcparse( $meta['APP13'] );

    if ( $iptc ) {
        // symplify array structure
        foreach ( $iptc as &$i ) {
            // if the array has only one item
            if ( count( $i ) <= 1 ) {
                $i = $i[0];
            }
        }

        // add named copies to all found IPTC items
        foreach ( $iptc as $key => $value ) {
            if ( isset( $this->IPTC_MAPPING[ $key ] ) ) {
                $name = $this->IPTC_MAPPING[ $key ];

                // add "Caption" alias to "Caption-Caption-Abstract"
                if ( $key == '2#120' ) {

                    /* 
                        2013.05.23
                        Coded by: Olav Alexander Mjelde
                        Compatabilityfix for *** Local Caption *** from FotoWare FotoStation 
                    */

                    $arrCaption = array_filter(explode(" *** Local Caption *** ", utf8_encode($value)));
                    $nCap = count($arrCaption);
                    $pri = 1; /* Which to prioritize? 0 = regular caption, 1 = *** Local Caption *** from FotoStation */

                    switch ($nCap) {
                        case 0: 
                            $value = $value;
                        break;
                        default:
                            (($pri <= $nCap - 1) && ($pri >= 0)) ? $value = $arrCaption[1] : $value = $arrCaption[0];           
                    }
                    /* End of Compatabilityfix by Olav Alexander Mjelde*/

                    $this->insert_next_to_key( $iptc, $key, array( 'Caption' => $value ) );
                }

                $this->insert_next_to_key( $iptc, $key, array( $name => utf8_encode($value)) ); /* UTF8 encoding added 25.05.2013 by Olav Alexander Mjelde */
            }
        }
    }

    if ( $iptc ) {
        $this->metadata['IPTC'] = $iptc;
    }

    // parse exif       
    $exif = NULL;

    // the exif_read_data() function throws a warning if it is passed an unsupported file format.
    // This warning is impossible to catch so we have to check the file mime type manually
    $safe_file_formats = array(
        'image/jpg',
        'image/jpeg',
        'image/tif',
        'image/tiff',
    );


    if ( in_array( $size['mime'], $safe_file_formats ) ) {

        $exif = exif_read_data( $tmp_name );

        if ( is_array( $exif ) ) {
            // add named copies of UndefinedTag:0x0000 items to $exif array
            foreach ( $exif as $key => $value ) {
                // check case insensitively if key begins with "UndefinedTag:"
                if ( strtolower( substr( $key, 0, 13 ) ) == 'undefinedtag:' ) {
                    // get EXIF tag name by ID and convert it to base 16 integer
                    $id = intval( substr( $key, 13 ), 16 );

                    if ( isset( $this->EXIF_MAPPING[ $id ] ) ) {
                        // create copy with EXIF tag name as key
                        $name = $this->EXIF_MAPPING[ $id ];
                        //$exif[ $name ] = $value;
                        $this->insert_next_to_key( $exif, $key, array( $name => $value ) );
                    }
                }
            }
        }

    }

    if ( $exif ) {
        $this->metadata['EXIF'] = $exif;
    }

    // no need for return but good for testing
    return $this->metadata;
}