How to add image watermarking to net c gif animation

 
public static Bitmap WaterMarkWithText(System.Drawing.Bitmap origialGif, string 
text,string filePath) 
{ 
// For storing frame  
List<Frame> frames = new 
List<Frame>(); 
// If it is not gif file , Return directly to the original image  
if (origialGif.RawFormat.Guid 
!= System.Drawing.Imaging.ImageFormat.Gif.Guid) 
{ 
return origialGif; 

} 
// If the image gif file  
foreach (Guid guid in 
origialGif.FrameDimensionsList) 
{ 
System.Drawing.Imaging.FrameDimension 
frameDimension = new System.Drawing.Imaging.FrameDimension(guid); 
int 
frameCount = origialGif.GetFrameCount(frameDimension); 
for (int i = 0; i 
< frameCount; i++) 
{ 
if (origialGif.SelectActiveFrame(frameDimension, 
i) == 0) 
{ 
int delay = 
Convert.ToInt32(origialGif.GetPropertyItem(20736).Value.GetValue(i)); 
Image 
img = Image.FromHbitmap(origialGif.GetHbitmap()); 
Font font = new Font(new 
FontFamily(" Song typeface "), 35.0f,FontStyle.Bold); 
Graphics g = 
Graphics.FromImage(img); 
g.DrawString(text, font, Brushes.BlanchedAlmond, 
new PointF(10.0f, 10.0f)); 
Frame frame = new Frame(img, delay); 

frames.Add(frame); 
} 
} 
Gif.Components.AnimatedGifEncoder gif = 
new Gif.Components.AnimatedGifEncoder(); 
gif.Start(filePath); 

gif.SetDelay(100); 
gif.SetRepeat(0); 
for (int i = 0; i < 
frames.Count; i++) 
{ 
gif.AddFrame(frames[i].Image); 
} 

gif.Finish(); 
try 
{ 
Bitmap gifImg = 
(Bitmap)Bitmap.FromFile(filePath); 
return gifImg; 
} 
catch 
{ 

return origialGif; 
} 
} 
return origialGif; 
}