How to convert multiple .png files to gif to creat gif animation in c#?

I tried this code below and it worked. But the problem is that, the quality is not good, I can see some colors are not good. I want to create gif that has good quality of resolution.

* create Gif */
//you should replace filepath
String[] imageFilePaths = new String[] { @"c:\gif\1\1.png", @"c:\gif\2\2.png", @"c:\gif\3\3.png", @"c:\gif\4\4.png", @"c:\gif\5\5.png", @"c:\gif\6\6.png"};
String outputFilePath = "c:\\test.gif";
AnimatedGifEncoder e = new AnimatedGifEncoder();
e.Start( outputFilePath );
e.SetDelay(500);
//-1:no repeat,0:always repeat
e.SetRepeat(0);
for (int i = 0, count = imageFilePaths.Length; i < count; i++ )
{
e.AddFrame( Image.FromFile( imageFilePaths[i] ) );
}
e.Finish();

Please help me this is urgent

You can use the RasterCodecs Save method to combine your images into a Gif file. You can then leverage the RasterImageAnimator class to display the gif animation. Here is some sample code and resources for this:

//Merge
static void MergeFiles(string[] files, string outputFile) 
{ 
   using (RasterCodecs codecs = new RasterCodecs()) 
      foreach (var file in files) 
         using (RasterImage image = codecs.Load(file)) 
            codecs.Save(image, outputFile, RasterImageFormat.Gif, 0, 1, -1, 1, CodecsSavePageMode.Append); 
} 

//Animate
private RasterImage FlattenAndReverse(RasterImage inputImage) 
{ 
   int w = inputImage.AnimationGlobalSize.Width, h = inputImage.AnimationGlobalSize.Height; 
   if (w <= 0) 
      w = inputImage.Width; 
   if (h <= 0) 
      h = inputImage.Height; 
   RasterImage renderImage = new RasterImage( 
      RasterMemoryFlags.Conventional, 
      w, 
      h, 
      inputImage.BitsPerPixel, 
      inputImage.Order, 
      inputImage.ViewPerspective, 
      null, 
      IntPtr.Zero, 
      0); 
   // Copy the palette from the animated image to this newly created image 
   inputImage.CopyPaletteTo(renderImage); 
   RasterImage flatImage = null; 
   // Create the RasterImageAnimator object 
   RasterImageAnimator _animator = new RasterImageAnimator(renderImage, inputImage); 
   // Animate it and save the frames in reverse order 
   // Use GDI+ paint engine to support transparent colors 
   RasterPaintProperties props = _pictureBox.PaintProperties; 
   props.PaintEngine = RasterPaintEngine.GdiPlus; 
   using (RasterImageGdiPlusGraphicsContainer _gdiPlusGraphics = new RasterImageGdiPlusGraphicsContainer(renderImage)) 
   { 
      Graphics g = _gdiPlusGraphics.Graphics; 
      RasterImageAnimatorState state; 
 
      bool done = false; 
      while (!done) 
      { 
         LeadRect srcRect = new LeadRect(0, 0, renderImage.ImageWidth, renderImage.ImageHeight); 
         LeadRect updateRect; 
         LeadRect destRect; 
 
         state = _animator.Process(); 
 
         switch (state) 
         { 
            case RasterImageAnimatorState.WaitDelay: 
            case RasterImageAnimatorState.WaitInputDelay: 
               // Set the animation delay into the last frame that got inserted 
               flatImage.AnimationDelay = _animator.Delay; 
               _animator.CancelWait(); 
               break; 
            case RasterImageAnimatorState.Render: 
               break; 
            case RasterImageAnimatorState.WaitInput: 
               // In case the animated image has the "wait for user input" flags, 
               // Cancel the waiting 
               _animator.CancelWait(); 
               break; 
            case RasterImageAnimatorState.PostRender: 
               // Get the area in the target image that has changed 
               updateRect = _animator.GetUpdateRectangle(true); 
               destRect = new LeadRect(0, 0, renderImage.ImageWidth, renderImage.ImageHeight); 
               // Paint it 
               RasterImagePainter.Paint(renderImage, g, srcRect, updateRect, destRect, destRect, props); 
               if (flatImage == null) 
                  flatImage = renderImage.Clone(); 
               else 
                  flatImage.InsertPage(0, renderImage.Clone()); // Insert at the beginning to reverse the frames 
               flatImage.Page = 1; // The newly inserted frame is always number 1 
               flatImage.AnimationDelay = 50; // Set value in case the animation doesn't provide one. 
               break; 
            case RasterImageAnimatorState.End: 
               done = true; // Exist the loop once animation is done 
               break; 
            default: 
               break; 
         } 
      } 
   } 
   return flatImage; 
}

https://www.leadtools.com/help/sdk/tutorials/dotnet-winforms-convert-a-multipage-image-to-reverse-animated-gif.html
https://www.leadtools.com/help/sdk/tutorials/dotnet-console-create-a-multipage-file-from-multiple-images.html