Windows 클립보드에 이미지를 복사할 때 투명성을 유지하는 방법은 무엇입니까?

public static void SetClipboardImage(Bitmap image, Bitmap imageNoTr, DataObject data)
{
    Clipboard.Clear();
    data ??= new DataObject(); //Null-conditional operator for brevity

    imageNoTr ??= image; //Null-conditional operator for brevity

    using (MemoryStream pngMemStream = new MemoryStream())
    using (MemoryStream dibMemStream = new MemoryStream())
    {
        data.SetData(DataFormats.Bitmap, true, imageNoTr);
        image.Save(pngMemStream, ImageFormat.Png);
        data.SetData("PNG", false, pngMemStream);

        byte[] dibData = ConvertToDib(image);
        dibMemStream.Write(dibData, 0, dibData.Length);
        data.SetData(DataFormats.Dib, false, dibMemStream);
        Clipboard.SetDataObject(data, true);
    }
}

public static Bitmap GetClipboardImage(DataObject retrievedData)
{
    Bitmap clipboardimage = null;

    if (retrievedData.GetDataPresent("PNG", false))
    {
        MemoryStream pngStream = retrievedData.GetData("PNG", false) as MemoryStream;
        using (Bitmap bm = new Bitmap(pngStream))
            clipboardimage = ImageUtils.CloneImage(bm);
    }
    else if (retrievedData.GetDataPresent(DataFormats.Dib, false))
    {
        MemoryStream dib = retrievedData.GetData(DataFormats.Dib, false) as MemoryStream;
        clipboardimage = dib != null ? ImageFromClipboardDib(dib.ToArray()) : null;
    }
    else if (retrievedData.GetDataPresent(DataFormats.Bitmap))
    {
        clipboardimage = new Bitmap(retrievedData.GetData(DataFormats.Bitmap) as Image);
    }
    else if (retrievedData.GetDataPresent(typeof(Image)))
    {
        clipboardimage = new Bitmap(retrievedData.GetData(typeof(Image)) as Image);
    }

    return clipboardimage;
}