ImgProc.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using System.IO;

namespace imgMessCons
{
    class ImgProc
    {
        private Bitmap bmp;

        public ImgProc(string filePath)
        {
            this.bmp = new Bitmap(filePath);
        }

        public void WriteMessage(string filePath, int step)
        {
            int width = this.bmp.Width,
                height = this.bmp.Height,
                key = 0;

            char ch = '\0';

            string strMess = string.Empty;

            TextReader reader = new StreamReader(filePath, Encoding.Default);

            strMess = reader.ReadToEnd();

            reader.Close();

            TableTranslation tblTr = new TableTranslation();

            strMess = strMess + tblTr.GetSymbol(tblTr.GetLength() - 1).ToString();

            int lenStr = strMess.Length;

            int indexStrMess = 0,
                indexStrMess2 = 0;


            for (int i = 0; i < width; i++)
            {
                for (int j = 0; j < height; j++)
                {
                    if ((indexStrMess + 1) % step == 0)
                    {
                        indexStrMess2 = (int)(indexStrMess / step);
                        if (indexStrMess2 >= lenStr)
                        {
                            indexStrMess2 = indexStrMess2 % lenStr;
                        }

                        ch = strMess[indexStrMess2];

                        key = tblTr.GetIndex(ch);

                        this.bmp.SetPixel(i, j, Color.FromArgb(key, key, key));
                    }

                    if (indexStrMess == 0)
                    {
                        key = step;

                        this.bmp.SetPixel(i, j, Color.FromArgb(key, key, key));
                    }

                    indexStrMess++;
                }

            }


        }

        public void ReadMessage(string filePath)
        {
            TableTranslation tbTr = new TableTranslation();

            int width = this.bmp.Width,
                heith = this.bmp.Height,
                step = 0,
                key = 0,
                finishKey = tbTr.GetLength() - 1;

            char ch = '\0';

            string strMess = string.Empty;

            Color clr;

            clr = this.bmp.GetPixel(0,0);

            step = (int)clr.R;

            int indexMess = 0;

            for (int i = 0; i < width; i++)
            {
                for (int j = 0; j < heith; j++)
                {
                    if ((indexMess + 1) % step == 0)
                    {
                        clr = this.bmp.GetPixel(i, j);

                        key = (int)clr.R;

                        ch = tbTr.GetSymbol(key);

                        strMess = strMess + ch.ToString();
                    }

                    if (key == finishKey)
                    {
                        i = width;
                        j = heith;
                    }

                    indexMess++;
                }
            }


            strMess = strMess.Substring(0, strMess.Length - 1);
            StreamWriter sw = new StreamWriter(filePath);

            sw.Write(strMess);

            sw.Close();

        }

        public void SaveImg(string WriteImgPath)
        {

            string imgWithMessPath = Path.GetDirectoryName(WriteImgPath) + @"\imgMess.png";

            this.bmp.Save(imgWithMessPath);

            this.bmp = null;

        }
    }
}