Accord.Imaging.Filters.FastGuidedFilter.GetFilledImage C# (CSharp) Method

        public static UnmanagedImage GetFilledImage(int width, int height, PixelFormat pixelFormat, Color color)
        {
            UnmanagedImage filledImage;

            var grayImage = UnmanagedImage.Create(width, height, PixelFormat.Format8bppIndexed);

            if (pixelFormat == PixelFormat.Format8bppIndexed ||
                pixelFormat == PixelFormat.Format16bppGrayScale)
            {
                SystemTools.SetUnmanagedMemory(
                    grayImage.ImageData,
                    (color.R + color.G + color.B) / 3,
                    grayImage.Stride * grayImage.Height);

                filledImage = pixelFormat == PixelFormat.Format8bppIndexed ? grayImage.Clone() :
                    UnmanagedImage.FromManagedImage(
                        Accord.Imaging.Image.Convert8bppTo16bpp(grayImage.ToManagedImage(false)));
            }
            else
            {
                filledImage = UnmanagedImage.Create(width, height, pixelFormat);

                if (pixelFormat == PixelFormat.Format24bppRgb)
                {
                    SystemTools.SetUnmanagedMemory(grayImage.ImageData, color.R, grayImage.Stride * grayImage.Height);
                    var replaceChannel = new ReplaceChannel(RGB.R, grayImage);
                    replaceChannel.ApplyInPlace(filledImage);

                    SystemTools.SetUnmanagedMemory(grayImage.ImageData, color.G, grayImage.Stride * grayImage.Height);
                    replaceChannel.Channel = RGB.G;
                    grayImage.Copy(replaceChannel.UnmanagedChannelImage);
                    replaceChannel.ApplyInPlace(filledImage);

                    SystemTools.SetUnmanagedMemory(grayImage.ImageData, color.B, grayImage.Stride * grayImage.Height);
                    replaceChannel.Channel = RGB.B;
                    grayImage.Copy(replaceChannel.UnmanagedChannelImage);
                    replaceChannel.ApplyInPlace(filledImage);
                }
                else
                {
                    SystemTools.SetUnmanagedMemory(grayImage.ImageData, color.R, grayImage.Stride * grayImage.Height);

                    UnmanagedImage grayImage16 = UnmanagedImage.FromManagedImage(
                        Accord.Imaging.Image.Convert8bppTo16bpp(grayImage.ToManagedImage(false)));

                    ReplaceChannel replaceChannel = new ReplaceChannel(RGB.R, grayImage16);
                    replaceChannel.ApplyInPlace(filledImage);


                    SystemTools.SetUnmanagedMemory(grayImage.ImageData, color.G, grayImage.Stride * grayImage.Height);

                    replaceChannel.Channel = RGB.G;
                    replaceChannel.UnmanagedChannelImage.Dispose();

                    replaceChannel.UnmanagedChannelImage =
                        UnmanagedImage.FromManagedImage(Accord.Imaging.Image.Convert8bppTo16bpp(
                            grayImage.ToManagedImage(false)));

                    replaceChannel.ApplyInPlace(filledImage);


                    SystemTools.SetUnmanagedMemory(grayImage.ImageData, color.B, grayImage.Stride * grayImage.Height);

                    replaceChannel.Channel = RGB.B;
                    replaceChannel.UnmanagedChannelImage.Dispose();

                    replaceChannel.UnmanagedChannelImage =
                        UnmanagedImage.FromManagedImage(Accord.Imaging.Image.Convert8bppTo16bpp(
                            grayImage.ToManagedImage(false)));

                    replaceChannel.ApplyInPlace(filledImage);
                    replaceChannel.UnmanagedChannelImage.Dispose();

                    grayImage16.Dispose();
                }
            }

            grayImage.Dispose();

            return filledImage;
        }
    }