public function imageUpload($input_file_name = 'image', $dest_filename)
    {
        if (isset($_FILES[$input_file_name])) {
            if (!empty($_FILES[$input_file_name]['error'])) {
                $upload_error_code = $_FILES[$input_file_name]['error'];
                if ($upload_error_code == 4) {
                    return false; // file not loaded (probably not choosen)
                } else {
                    throw new Exception(
                        $this->fileUploadCodeToMessage($upload_error_code));
                }
            } else {
                $uploaded = $_FILES[$input_file_name]['tmp_name'];
                if (!is_uploaded_file($uploaded)) {
                    throw new Exception(
                        "Possible file upload attack: ".$uploaded);
                }
                if (!file_exists($uploaded)) {
                    throw new Exception( "File: ".$uploaded." not found.");
                }
                // is image?
                if (!$size = getimagesize($uploaded)){
                    throw new Exception('Unsupported file format');
                }
                $dirname = dirname($dest_filename);
                if (!is_dir($dirname)) {
                    // full for owner, read and exec(?) for others, recursive creation
                    mkdir($dirname, 0755, true);
                }
                if (move_uploaded_file($uploaded, $dest_filename)) {
                    chmod($dest_filename, 0644); // RW for owner, read for everybody else
                    return true;
                } else {
                    throw new Exception(
                        "Can't move uploaded file: "
                        ."\nfilesize=".filesize($uploaded)
                        ."\ndisk_free_space=".disk_free_space($dirname));
                }
            }
        } else return false;
    }
    public function fileUploadCodeToMessage($code) {
        switch ($code) {
            case UPLOAD_ERR_INI_SIZE:
                return "php.ini upload_max_filesize exceeded";
            case UPLOAD_ERR_FORM_SIZE:
                return "HTML form MAX_FILE_SIZE exceeded";
            case UPLOAD_ERR_PARTIAL:
                return "The uploaded file was only partially uploaded";
            case UPLOAD_ERR_NO_FILE:
                return "No file was attached";
            case UPLOAD_ERR_NO_TMP_DIR:
                return "Missing a temporary folder";
            case UPLOAD_ERR_CANT_WRITE:
                return "Failed to write file to disk";
            case UPLOAD_ERR_EXTENSION:
                return "File upload stopped by extension";
            default:
                return "Unknown upload error (code $code)";
        }
    }