Sort Duplicate Image Algorithm

private void button1_Click(object sender, EventArgs e)
{
    string original = @"C:\Users\user\Documents\CaptchaCollection\";

    var files = Directory.GetFiles(original)
                .Select(nameWithExtension => Path.GetFileNameWithoutExtension(nameWithExtension))
                .Where(name => { int number; return int.TryParse(name, out number); })
                .Select(name => int.Parse(name))
                .OrderBy(number => number).ToArray();

    Bitmap[] images = new Bitmap[files.Length];

    for (int i = 0; i < images.Length; i++)
    {
        images[i] = new Bitmap(original + i + "png");
    }

    var imageHashes = new List<byte[]>();

    for (int i = 0; i < images.Length; i++)
    {
        imageHashes.Add(HashImage(images[i]));
    }

    var equivalentImages = images.Select(i => Tuple.Create(HashImage(i), original(i)))
                        .GroupBy(t => t.Item1);
}