eZ\Publish\Core\FieldType\Image\PathGenerator\LegacyPathGenerator::getDirectoryStructure PHP Метод

    private function getDirectoryStructure($id)
    {
        // our base string is the last 4 digits, defaulting to 0, reversed
        $idString = strrev(substr(str_pad($id, 4, 0, STR_PAD_LEFT), -4));
        return trim(chunk_split($idString, 1, '/'), '/');
    }