using System;

using System.Drawing;

using System.IO;

using System.Drawing.Imaging;

using ICSharpCode.SharpZipLib.Zip.Compression;

using System.Runtime.InteropServices;       

using System.Linq;

​

public class Program

{

    public static Bitmap ArrayToBitmap(byte[] bytes, int width, int height, System.Drawing.Imaging.PixelFormat pixelFormat)

    {

        var image = new Bitmap(width, height, pixelFormat);

        var imageData = image.LockBits(new System.Drawing.Rectangle(0, 0, image.Width, image.Height),

                    ImageLockMode.ReadWrite, pixelFormat);

        try

        {

            Marshal.Copy(bytes, 0, imageData.Scan0, bytes.Length);

        }

        finally

        {

            image.UnlockBits(imageData);

        }

        return image;

    }

​

    public static byte[] Decompress(byte[] data)

    {

        // Create the compressor with highest level of compression

        Inflater inflater = new Inflater(true);

        inflater.SetInput(data);

​

        // Compress the data

        byte[] buf = new byte[1024];

        int count = 0;

        using (MemoryStream memory = new MemoryStream())

        {

            while (!inflater.IsFinished)

            {

                count = inflater.Inflate(buf);

                if (count > 0)

                {

                    memory.Write(buf, 0, count);

                }

                else

                {

                    break;

                }

            }

​

            count = inflater.Inflate(buf);

            if (count > 0)

            {

                memory.Write(buf, 0, count);

            }

​

            return memory.ToArray();

        }

    }

​

    public static byte[] Compress(byte[] data)

    {

        // Create the compressor with highest level of compression

        Deflater deflater = new Deflater(Deflater.DEFAULT_COMPRESSION, true);

        deflater.SetStrategy(DeflateStrategy.Default);

        deflater.SetInput(data);

        deflater.Finish();

​

        // Compress the data

        byte[] buf = new byte[1024];

        int count = 0;

        using (MemoryStream memory = new MemoryStream())

        {

            while (!deflater.IsFinished)

            {

                count = deflater.Deflate(buf);

                if (count > 0)

                {

                    memory.Write(buf, 0, count);

                }

                else

                {

                    break;

                }

            }

​

            count = deflater.Deflate(buf);

            if (count > 0)

            {

                memory.Write(buf, 0, count);

            }

​

            return memory.ToArray();

        }

    }

    public static string HexBytes(byte[] bytes) {

        return string.Join(" ", bytes.Select(b => string.Format("{0:x2}", b)).ToArray());

    }

​

    public static void Main(string[] args)

    {

        //raw data

        string zipString = "eJztlDEOgzAMRY0YsqDmBvVRci02OBpH4QiMDBHpVj+QojaVEFDxp6fIdr4dKyJfy/UHsKaUSvgon1vhvMrEe7CCO5SJhvWMMiNSB+OAMotFpAieMoyrkLuuybvogd7oedULe2TvnAlnxRl+VPGeVKM7FcvkydZZDMYdHiaANbMbv6t0nk9p3f+wkHdVUxsrtkH98OYAVmf8yP4+t66iF1UlgLg=";

        var a = Convert.FromBase64String(zipString);

        var z64 = a.Skip(2).ToArray();//skip the header "eJ"

        byte[] uzipZ64 = Decompress(z64);

        // int bytesPerRow = 12;

        // int width = bytesPerRow * 8;

        // int height = uzipZ64.Length / bytesPerRow;

        // var decodedBitmap = ArrayToBitmap(uzipZ64, width, height, System.Drawing.Imaging.PixelFormat.Format1bppIndexed);

​

        //save image

        // string file = string.Format(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "test.png"));

        // decodedBitmap.Save(file);

​

        //compress the image again

        byte[] new_z64 = Compress(uzipZ64);

        byte[] newData = new byte[new_z64.Length + 2];

        newData[0] = 120;//e, add the header "eJ"

        newData[1] = 156;//J

        Array.Copy(new_z64, 0, newData, 2, new_z64.Length);

        string newZipString = Convert.ToBase64String(newData); //new result

​

        //but it's not same from one source.

        bool isSame = zipString.Equals(newZipString);

        Console.WriteLine(zipString);

        Console.WriteLine(newZipString);

        Console.WriteLine();

        Console.WriteLine(HexBytes(a));

        Console.WriteLine(HexBytes(newData));

​

        Console.WriteLine();

        Console.WriteLine(HexBytes(a));

        Console.WriteLine(HexBytes(newData));

​

        Console.WriteLine();

    }

}