Utility to combine multiple TIFFs into a single multi-page TIFF

TiffCombiner.cs

public class ImageUtilities
    {
    //refrence https://stackoverflow.com/questions/398388/convert-bitmaps-to-one-multipage-tiff-image-in-net-2-0
    
        private const string Encoder = "image/tiff";

        public static Image CombineFiles(string[] inputFiles, string output)
        {
            Image multiPageFile = null;
            byte[] ba = null;
            
            var tiffCodec = ImageCodecInfo.GetImageEncoders().FirstOrDefault(t => t.MimeType == Encoder);

            using (var ms = new MemoryStream())
            {
                for (var i = 0; i < inputFiles.Length; ++i)
                {
                    var firstPage = i == 0;

                    var inputFile = inputFiles[i];

                    multiPageFile = LoadImage(inputFile, firstPage, multiPageFile, tiffCodec, ms);
                }

                ba = ms.ToArray();
            }

            File.WriteAllBytes(output, ba);

            return multiPageFile;
        }

        private static Image LoadImage(string inputFile, bool firstPage, Image multiPageFile, ImageCodecInfo tiffCodec, MemoryStream ms)
        {
            using (var inputImage = Image.FromFile(inputFile))
            {
                using (var byteStream = new MemoryStream())
                {
                    inputImage.Save(byteStream, ImageFormat.Tiff);

                    if (firstPage)
                    {
                        multiPageFile = Image.FromStream(byteStream);
                        multiPageFile = SaveImages(tiffCodec, ms, multiPageFile, null);
                    }
                    else
                    {
                        using (var tiffImage = Image.FromStream(byteStream))
                        {
                            multiPageFile = SaveImages(tiffCodec, ms, tiffImage, multiPageFile);
                        }
                    }
                }
            }

            return multiPageFile;
        }

        private static Image SaveImages(ImageCodecInfo tiffCodec, 
                                      Stream outputStream, 
                                      Image tiffImage,
                                      Image firstImage)
        {

            using (var encParameters = new EncoderParameters(3))
            {

                if (firstImage == null)
                {
                    encParameters.Param[0] = new EncoderParameter(
                        System.Drawing.Imaging.Encoder.SaveFlag
                        , (long)EncoderValue.MultiFrame // 18L 
                    );
                }
                else
                {
                    encParameters.Param[0] = new EncoderParameter(
                        System.Drawing.Imaging.Encoder.SaveFlag
                        , (long)EncoderValue.FrameDimensionPage // 23L
                    );
                }

                encParameters.Param[1] = new EncoderParameter(
                    System.Drawing.Imaging.Encoder.ColorDepth, 24L
                );

                encParameters.Param[2] = new EncoderParameter(
                    System.Drawing.Imaging.Encoder.Compression
                    , (long)EncoderValue.CompressionLZW
                );

                if (firstImage == null)
                {
                    firstImage = tiffImage;

                    ((Bitmap)tiffImage).SetResolution(96, 96);
                    firstImage.Save(outputStream, tiffCodec, encParameters);
                }
                else
                {
                    ((Bitmap)tiffImage).SetResolution(96, 96);

                    firstImage.SaveAdd(tiffImage, encParameters);
                }

                encParameters.Param[0]?.Dispose();

                encParameters.Param[1]?.Dispose();

                encParameters.Param[2]?.Dispose();

            }

            return firstImage;
        }


    }