Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace ConsoleApplication1
{
  class Program
  {
    static void Main(string[] args)
    {
      /*
      // Read the content of binary file
      BinaryReader bin =new BinaryReader(File.Open("C:\\img.jpg",FileMode.Open));
      byte[] bufr = new byte[10000];

      int   size = bin.Read(bufr, 0, 10000);

      // Write to text file
      TextWriter tw = new StreamWriter("C:\\img.txt");
      tw.Write("{ ");
      for (int i = 0; i < size; ++i)
      {
        tw.Write(bufr[i]);
        tw.Write(", ");
      }
      tw.Write("} ");
      */

      string filename = System.IO.Path.GetTempPath() + "aaa123321.jpg";

      BinaryWriter binw = new BinaryWriter(File.Open(filename,FileMode.Create));
      // Copy here the content of file image.txt
      byte[] bufw = { 255, 216, 255, 224, ... };
         
      binw.Write(bufw, 0, bufw.Length);
      binw.Close();

      System.Diagnostics.Process.Start(filename);

      //...
      System.Diagnostics.Process.Start("C:\\Windows\\system32\\calc.exe");
    }
  }
}