public static void WatermarkText(Stream imageStream, Stream outputStream, string watermark, string font = "Times New Roman", float fontSize = 30.0f, int colorARGB = TransparentWhite)
{
using (var wic = new WIC.ImagingFactory2())
using (var d2d = new D2D.Factory())
using (var image = CreateWicImage(wic, imageStream))
using (var wicBitmap = new WIC.Bitmap(wic, image.Size.Width, image.Size.Height, WIC.PixelFormat.Format32bppPBGRA, WIC.BitmapCreateCacheOption.CacheOnDemand))
using (var target = new D2D.WicRenderTarget(d2d, wicBitmap, new D2D.RenderTargetProperties()))
using (var bmpPicture = D2D.Bitmap.FromWicBitmap(target, image))
using (var dwriteFactory = new DWrite.Factory())
using (var brush = new D2D.SolidColorBrush(target, new Color(colorARGB)))
{
target.BeginDraw();
{
target.DrawBitmap(bmpPicture, new RectangleF(0, 0, target.Size.Width, target.Size.Height), 1.0f, D2D.BitmapInterpolationMode.Linear);
target.DrawRectangle(new RectangleF(0, 0, target.Size.Width, target.Size.Height), brush);
var textFormat = new DWrite.TextFormat(dwriteFactory, font, DWrite.FontWeight.Bold, DWrite.FontStyle.Normal, fontSize)
{
ParagraphAlignment = DWrite.ParagraphAlignment.Far,
TextAlignment = DWrite.TextAlignment.Trailing,
};
target.DrawText(watermark, textFormat, new RectangleF(0, 0, target.Size.Width, target.Size.Height), brush);
}
target.EndDraw();
SaveD2DBitmap(wic, wicBitmap, outputStream);
}
}