PHP如何实现将文件转二进制输出

header( "Content-type: image/jpeg");
$PSize = filesize('1.jpg');
$picturedata = fread(fopen('1.jpg', "r"), $PSize);
echo $picturedata;

 /**
    * 支持文件类型上传到OSS
    */
    public static  function uploadFile($filename, $ext = 'jpg', $type = Enum_OSS_File_Type::IMG) {
        $content = static::file2content($filename);
        return static::upload($content, $ext, $type);
    }
    
    public static  function file2content($filename) {
        return fread(fopen($filename, 'r'), filesize($filename));
    }