test.cs

using (TXTextControl.ServerTextControl tx = new TXTextControl.ServerTextControl())
	{
		tx.Create();
	
		tx.Load("invoice.docx", TXTextControl.StreamType.WordprocessingML);
	
		TXTextControl.SaveSettings saveSettings = new TXTextControl.SaveSettings()
		{
			ImageSaveMode = TXTextControl.ImageSaveMode.SaveAsData
		};
	
		string doc = "";
	
		tx.Save(out doc, TXTextControl.StringStreamType.HTMLFormat, saveSettings);
	
		var images = GetImageBase64Strings(doc);
	
		foreach (var image in images)
		{
			byte[] imageBytes = Convert.FromBase64String(image.Base64Content);
	
			// write byte array to file
			using (FileStream fs = new FileStream("image" + image.Extension, FileMode.Create))
			{
				fs.Write(imageBytes, 0, imageBytes.Length);
			}
		}
	}