File to color pixels and back!

Pixelate.cs

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

class Pixelate {
      static void Main(string[] args) {
          /*string s = "acxbca", str = "";
          int start = 0, end = s.Length - 1;
          float mid = ((float)start + end) / 2.0f;
          while (start <= end) {
              if (s[start] == s[end] && mid >= (start + end) / 2) {
                  str += s[start];
              }
              start++;
              end--;
              Console.Write(start + " -- " + end + "\n");
          }
          Console.WriteLine(str);*/

          /*using (Bitmap bmp = new Bitmap(@"C:\Users\AWAiS\Desktop\Untitled.png")) {
              int height = bmp.Height, width = bmp.Width;
              for (int i = 0; i < height; i++) {
                  for (int j = 0; j < width; j++) {
                      Color pixel = bmp.GetPixel(j, i);
                      if (pixel.A < 255) continue;
                      Console.WriteLine($"{i},{j}: {pixel.R.ToString("X2")},{pixel.G.ToString("X2")},{pixel.B.ToString("X2")}");
                  }
                  Console.WriteLine();
              }
          }*/

          /*using (FileStream file = File.Open(@"C:\Users\AWAiS\Desktop\Untitled.png", FileMode.Open)) {
              int b, x = 0;
              string str = "";
              while ((b = file.ReadByte()) >= 0) {
                  string s = b.ToString("X2");
                  if (x < 3) {
                      x++;
                      str += s;
                  } else {
                      x = 0;
                      str += ",";
                  }
              }
              if (str.EndsWith(","))
                  str = str.Substring(0, str.Length - 1);
              string[] lel = str.Split(',');
              if (lel[lel.Length - 1].Length == 2) {
                  lel[lel.Length - 1] = lel[lel.Length - 1] + "----";
              } else if (lel[lel.Length - 1].Length == 4) {
                  lel[lel.Length - 1] = lel[lel.Length - 1] + "--";
              }

              foreach (var item in lel) {
                  Console.Write(item+",");
              }
              file.Close();
          }*/

          using (FileStream fs = new FileStream(@"C:\Users\AWAiS\Desktop\test\to_be_packed.png", FileMode.Open)) {
              int hexIn, i = 0, x = 0;
              long l = fs.Length;
              StringBuilder str = new StringBuilder();
              while ((hexIn = fs.ReadByte()) != -1) {
                  if (i<2) {
                      str.Append(hexIn.ToString("X2"));
                      if (i < 1) str.Append(",");
                  } else {
                      i = 0;
                      str.Append("," + hexIn.ToString("X2"));
                      str.Append("|");
                      continue;
                  }
                  i++;
              }

              // |09,E5 = 2 bytes
              // |09,   = 1 byte
              // |      = 0 bytes

              if (str[str.Length - 1] == '|') str = str.Remove(str.Length - 1, 1);
              if (str[str.Length - 6] == '|') str.Append(",XX");
              if (str[str.Length - 4] == '|') str.Append("XX,XX");

              int len = (int)(fs.Length / 3) + 1, y = 0;
              Bitmap resultImage = new Bitmap(len, 3, PixelFormat.Format32bppArgb);
              resultImage.MakeTransparent(Color.Transparent);
              foreach (var chunk in str.ToString().Split('|')) {
                  string[] bits = chunk.Split(',');
                  string a = "00";
                  string r = (bits[0] == "XX" ? "00" : bits[0]);
                  string g = (bits[1] == "XX" ? "00" : bits[1]);
                  string b = (bits[2] == "XX" ? "00" : bits[2]);

                  if (bits[1] == "XX") a = "90";
                  if (bits[2] == "XX") a = "A0";
                  if (bits[1] != "XX" && bits[2] != "XX") a = "FF";

                  Color clr = ColorTranslator.FromHtml("#" + a + r + g + b);
                  resultImage.SetPixel(x, y, clr);
                  x++;
                  if (x >= len) {
                      y++; x = 0;
                  }
                  Console.WriteLine($"LEN: {len}, x: {x}, y: {y}");
              }
              resultImage.Save(@"C:\Users\AWAiS\Desktop\test\packed.png");
          }

          bitmapToFile(@"C:\Users\AWAiS\Desktop\test\packed.png", @"C:\Users\AWAiS\Desktop\test\test.png");
      }

      public static void bitmapToFile(string bitmap, string outFile) {
          using (Bitmap bmp = new Bitmap(bitmap)) {
              int height = bmp.Height, width = bmp.Width;
              StringBuilder str = new StringBuilder();
              for (int h = 0; h < height; h++) {
                  for (int w = 0; w < width; w++) {
                      Color pixel = bmp.GetPixel(w, h);
                      int bytesUsed = 3;
                      if (pixel.A == 0) continue;
                      else if (pixel.A >= 100 && pixel.A <= 150) bytesUsed = 1;
                      else if (pixel.A > 150 && pixel.A < 255) bytesUsed = 2;

                      switch (bytesUsed) {
                          case 1:
                              str.Append(pixel.R.ToString("X2")); break;
                          case 2:
                              str.Append(pixel.R.ToString("X2"));
                              str.Append(pixel.G.ToString("X2")); break;
                          case 3:
                              str.Append(pixel.R.ToString("X2"));
                              str.Append(pixel.G.ToString("X2"));
                              str.Append(pixel.B.ToString("X2")); break;
                      }
                  }
              }

              File.WriteAllBytes(outFile, StringToByteArray(str.ToString()));
          }
      }
      public static byte[] StringToByteArray(string hex) {
          return Enumerable.Range(0, hex.Length).Where(x => x % 2 == 0).Select(x => Convert.ToByte(hex.Substring(x, 2), 16)).ToArray();
      }
  }