title: FreeImage - Write zTXt tag to PNG
body: <p>This is really causing me a headache.  For some reason or another, I can add a specific tag to a PNG file, but it's not adding the way I'd like and I don't know how to get it to write the way I want</p>
  
  <p>Given the code;</p>
  
  <pre><code>    Dim FImage As FIBITMAP = FreeImage.CreateFromBitmap(Image)
  
      Dim FTag As New Metadata.MetadataTag(FREE_IMAGE_MDMODEL.FIMD_COMMENTS)
      FTag.Key = "Description"
      FTag.ID = 270
  
      FTag.Value = Encoding.ASCII.GetBytes(DescString.ToString)
      FTag.AddToImage(FImage)
  
  
      FreeImage.Save(FREE_IMAGE_FORMAT.FIF_PNG, FImage, fbSaveTo.SelectedPath &amp; "\TEST.dmi", FREE_IMAGE_SAVE_FLAGS.EXR_ZIP Or FREE_IMAGE_SAVE_FLAGS.PNG_Z_BEST_COMPRESSION)
  </code></pre>
  
  <p>Assume that Image is valid and that DescString is too (it's a stringbuilder).  I'm trying to add the Image Description tag, which I want to have written <em>specifically</em> as a <code>zTXt</code> chunk in the PNG file, as I need to have that format in order for the file to be compatible with another target program (Dream Maker).  Instead, it writes an <code>iTXt</code> tag, which Dream Maker doesn't read which makes the file useless.</p>
  
  <p>Can anyone familiar with FreeImage help me out, or could anyone recommend an alternative that I can integrate into my program?</p>