ทำโปรเจค Asp.Net(c#) รบกวนหน่อยครับ upload รูปเข้ามา แล้วตัดสีออกทั้งหมด ให้เหลือแต่เส้นขอบสีดำ

        public static Bitmap EdgeDetection(Bitmap Image, float Threshold, Color EdgeColor)
        {
            System.Drawing.Bitmap TempBitmap = Image;
            System.Drawing.Bitmap NewBitmap = new System.Drawing.Bitmap(TempBitmap.Width, TempBitmap.Height);
            System.Drawing.Graphics NewGraphics = System.Drawing.Graphics.FromImage(NewBitmap);
            NewGraphics.DrawImage(TempBitmap, new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), System.Drawing.GraphicsUnit.Pixel);
            NewGraphics.Dispose();
            for (int x = 0; x < NewBitmap.Width; ++x)
            {
                for (int y = 0; y < NewBitmap.Height; ++y)
                {
                    bool EdgeSet = false;
                    Color CurrentColor = NewBitmap.GetPixel(x, y);
                    if (y < NewBitmap.Height - 1 && x < NewBitmap.Width - 1)
                    {
                        Color TempColor = NewBitmap.GetPixel(x + 1, y + 1);
                        if (Math.Sqrt(((CurrentColor.R - TempColor.R) * (CurrentColor.R - TempColor.R)) +
                            ((CurrentColor.G - TempColor.G) * (CurrentColor.G - TempColor.G)) +
                            ((CurrentColor.B - TempColor.B) * (CurrentColor.B - TempColor.B))) > Threshold)
                        {
                            NewBitmap.SetPixel(x, y, EdgeColor);
                        }
                        EdgeSet = true;
                    }
                    if (y < NewBitmap.Height - 1&&!EdgeSet)
                    {
                        Color TempColor = NewBitmap.GetPixel(x, y + 1);
                        if (Math.Sqrt(((CurrentColor.R - TempColor.R) * (CurrentColor.R - TempColor.R)) +
                            ((CurrentColor.G - TempColor.G) * (CurrentColor.G - TempColor.G)) +
                            ((CurrentColor.B - TempColor.B) * (CurrentColor.B - TempColor.B))) > Threshold)
                        {
                            NewBitmap.SetPixel(x, y, EdgeColor);
                        }
                        EdgeSet = true;
                    }
                    if (x < NewBitmap.Width - 1&&!EdgeSet)
                    {
                        Color TempColor = NewBitmap.GetPixel(x + 1, y);
                        if (Math.Sqrt(((CurrentColor.R - TempColor.R) * (CurrentColor.R - TempColor.R)) +
                            ((CurrentColor.G - TempColor.G) * (CurrentColor.G - TempColor.G)) +
                            ((CurrentColor.B - TempColor.B) * (CurrentColor.B - TempColor.B))) > Threshold)
                        {
                            NewBitmap.SetPixel(x, y, EdgeColor);
                        }
                        EdgeSet = true;
                    }
                }
            }
            return NewBitmap;
        }