Trying to improve multi-page TIFF file splitting

Question

I am trying to improve the speed at which I am able to split a multi-page TIFF file into it's individual pages, stored as a list of byte arrays. I have this TiffSplitter class that I'm working on, to try and improve the speed of the Paginate method.

I have heard of LibTiff.net, and wonder if it would be any faster than this process? Currently, it takes about 1333 ms to call the Paginate method on a 7-page multipage TIFF file.

Does anyone know what would be the most efficient way to retrieve the individual pages of a multipage TIFF as byte arrays? Or possibly have any suggestions as to how I can improve the speed of the process I'm currently using?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

namespace TiffSplitter
{
    public class TiffPaginator
    {
        private List<byte[]> paginatedData;
        public List<byte[]> Pages
        {
            get
            {
                return paginatedData;
            }
        }

        public TiffPaginator()
        {
            paginatedData = new List<byte[]>();
        }

        public void Paginate(string Filename)
        {
            using (Image img = Image.FromFile(Filename))
            {
                paginatedData.Clear();
                int frameCount = img.GetFrameCount(FrameDimension.Page);
                for (int i = 0; i < frameCount; i++)
                {
                    img.SelectActiveFrame(new FrameDimension(img.FrameDimensionsList[0]), i);
                    using (MemoryStream memstr = new MemoryStream())
                    {
                        img.Save(memstr, ImageFormat.Tiff);
                        paginatedData.Add(memstr.ToArray());
                    }
                }
            }
        }
    }
}

Answer 1

I tried using the LibTiff.net, and for me, it was quite slow. The time to split a singe 2-page tif was measured in seconds. In the end, I decided to reference PresentationCore and go with this: (It splits the images to multiple files, but it should be simple to switch the output to byte arrays)

Stream imageStreamSource = new FileStream("filename", FileMode.Open, FileAccess.Read, FileShare.Read);
TiffBitmapDecoder decoder = new TiffBitmapDecoder(imageStreamSource, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
int pagecount = decoder.Frames.Count;
if (pagecount > 1)
{
    string fNameBase = Path.GetFileNameWithoutExtension("filename");
    string filePath = Path.GetDirectoryName("filename");
    for (int i = 0; i < pagecount; i++)
    {
        string outputName = string.Format(@"{0}\SplitImages\{1}-{2}.tif", filePath, fNameBase, i.ToString());
        FileStream stream = new FileStream(outputName, FileMode.Create, FileAccess.Write);
        TiffBitmapEncoder encoder = new TiffBitmapEncoder();
        encoder.Frames.Add(decoder.Frames[i]);
        encoder.Save(stream);
        stream.Dispose();                        
    }
    imageStreamSource.Dispose();
}