C#/System.Drawing: Preserve COM marker in JPEG file (no EXIF)

Question

I am doing a 90° rotation with minimal loss, using the following code:

System.Drawing.Image originalImage = System.Drawing.Image.FromFile("input.jpg");
ImageFormat sourceFormat = originalImage.RawFormat;
EncoderParameters encoderParams = null;
try
{
    if (sourceFormat.Guid == ImageFormat.Jpeg.Guid)
    {
        encoderParams = new EncoderParameters(1);
        encoderParams.Param[0] = new EncoderParameter(Encoder.Transformation,
            (long)EncoderValue.TransformRotate90);
    }
    originalImage.Save("output.jpg", GetEncoder(sourceFormat), encoderParams);
}
finally
{
    if (encoderParams != null)
        encoderParams.Dispose();
}

However the Save function seems to create EXIF metadata from the original (pure, no EXIF) JPEG COM marker (0xFE). I do not want EXIF markers in the output JPEG. I also want to preserve the original COM marked. What C# API in my application can I use instead to save my rotated buffer ?

Using jpegdump (dicom3tools package):

$ jpegdump < input.jpg
[...]
Offset 0x0014 Marker 0xfffe COM Comment length variable 0x10

While:

$ jpegdump < output.jpg
[...]
Offset 0x0014 Marker 0xffe1 APP1 Reserved for Application Use length variable 0x5a

Answer 1

Turns out the only working solution I could come up with, was saving the JPEG to a MemoryStream and then post process this temporary Stream using the solution described at:

• https://stackoverflow.com/a/1252097/136285

Pseudo code:

var jpegPatcher = new JpegPatcher();
FileStream outFile = new FileStream(fileName, FileMode.Open, FileAccess.Write);
jpegPatcher.PatchAwayExif(inStream, outFile);

I used the code from the blog, which does:

private void SkipAppHeaderSection(Stream inStream)
...
  while (header[0] == 0xff && (header[1] >= 0xe0 && header[1] <= 0xef))

So the function name PatchAwayExif is a bit odd since it also remove the APP0 (aka JFIF) segment...but that was something I also needed.