C# 如何解码未知的二进制图像编码？

我有包含SVG图像的XML文件。图像用base64编码，可能是gzip（根据制造商）

内容是这样的

<Image ID="ID_IMG57" ElementID="ID_IMG57" PMD="svg" X="1281" Y="370" ZIndex="-2" 
      W="36" H="56" MirrorX="False" MirrorY="False" Angle="0" ViewID="" Locked="False" 
      PlacementAngle="-360" PlacementX="1" PlacementY="27" PlacementScale="0" 
      Format="image/svg+base64" IncludeRelevantModules="True">
   <ImageValue>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
   </ImageValue>
   <ImageAttributes>
       <ImageAttribute Name="FileNameSVG" Value="Blickrichtung1.svg" Source="User" />
   </ImageAttributes>
</Image>

但是图像没有显示任何内容。我如何确定这背后的格式

---

我还尝试了仅base64解码并将数据保存到文件中。我希望能在二进制文件中看到类似文件类型的内容，但运气不好。

像@BigBadaboom一样，它是一个压缩流。下面将在

svg

中生成可读的XML

    string svg;
    using (var stream = new DeflateStream(new MemoryStream(compressed),  
        CompressionMode.Decompress))
    {
        using (MemoryStream memory = new MemoryStream())
        {
            stream.CopyTo(memory);
            byte[] decompressed = memory.GetBuffer();
            svg = Encoding.UTF8.GetString(decompressed);  
        }     
    }

---

解码后的数据看起来是加密的。您可能需要分析处理这些文件的软件，以了解它是如何提取图像的。我认为它是加密的。不太确定，大多数加密不会留下像那样的填充尾巴。@juergend-你想要一个位图或一堆SVG代码吗？@HenkHolterman:结果应该是一个单独的SVG图像文件，可以用浏览器或图像应用程序查看。根据XML属性，XML中的内容类型为

image/svg+base64

。

    string svg;
    using (var stream = new DeflateStream(new MemoryStream(compressed),  
        CompressionMode.Decompress))
    {
        using (MemoryStream memory = new MemoryStream())
        {
            stream.CopyTo(memory);
            byte[] decompressed = memory.GetBuffer();
            svg = Encoding.UTF8.GetString(decompressed);  
        }     
    }