SharpTesseract/TestVideo/Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Emgu.CV;
using Emgu.CV.OCR;
using Emgu.CV.Structure;
using System.IO;

namespace TestVideo
{
    public partial class Form1 : Form
    {
        public Screen[] screens;
        Screen currentScreen;
        List<string> screenNames;

        Image displayedImage = null;
        public Form1()
        {
            InitializeComponent();
            screens = Screen.AllScreens;
            currentScreen = screens[0];
            screenNames = new List<string>();
            foreach (Screen scr in screens)
            {
                screenNames.Add(scr.DeviceName);
            }
            lsbScreens.DataSource = screenNames;

            //TESTING TESSERACT

            //string path = AppDomain.CurrentDomain.BaseDirectory + "Screens\\Baneer.png";
            //string path = AppDomain.CurrentDomain.BaseDirectory + "Screens\\Test.png";
            //string path = AppDomain.CurrentDomain.BaseDirectory + "Screens\\Standings.png";
            //string path = AppDomain.CurrentDomain.BaseDirectory + "Screens\\Gaps.png";
            //string path = AppDomain.CurrentDomain.BaseDirectory + "Screens\\SectorTimes.png";
            string path = AppDomain.CurrentDomain.BaseDirectory + "Screens\\Standings2.png";

            tbxResult.Text = DecodeTessereactResults(testTesseract((Bitmap)Image.FromFile(path)), Image.FromFile(path), pbxOutput);
        }
        private Bitmap PrepareImage(Bitmap inputImage)
        {
            for (int y = 0; y < inputImage.Height; y++)
            {
                for (int x = 0; x < inputImage.Width; x++)
                {
                    //We will apply a filter to put the image first in grayScale
                    //Then if the pixel is more white than black it will be fully white and same for black

                    //Grayscale = 0.299R + 0.587G + 0.114B
                    Color color = inputImage.GetPixel(x, y);
                    int grayScaleValue = Convert.ToInt32(0.299 * (float)color.R + 0.587 * (float)color.G + 0.114 * (float)color.B);
                    int finalValue = 0;
                    if (grayScaleValue > 255 / 2)
                        finalValue = 255;
                    inputImage.SetPixel(x, y, Color.FromArgb(finalValue, finalValue, finalValue));
                }
            }
            //inputImage.Save("C:/TEST/test.png",ImageFormat.Png);
            return inputImage;
        }
        private string DecodeTessereactResults(string tesseractResult, Image inputImage, PictureBox resultPbx)
        {
            MessageBox.Show(tesseractResult);
            string result = "";
            string[] lettersData = tesseractResult.Split('\n');
            using (Graphics g = Graphics.FromImage(inputImage))
            {
                foreach (string letterData in lettersData)
                {
                    string[] data = letterData.Split(' ');
                    //This data is in a format that we cant process
                    if (data.Length != 6)
                        break;

                    string letter = data[0];
                    Point position = new Point(Convert.ToInt32(data[1]), Convert.ToInt32(data[2]));
                    Size size = new Size(Convert.ToInt32(data[3]), Convert.ToInt32(data[4]));
                    int unknownData = Convert.ToInt32(data[5]);

                    //A neat post processing Idea would be to separate letters that have a unusually big difference in X or Y axis to try and recognise words

                    //Use the data
                    result += letter;
                    g.DrawRectangle(new Pen(Brushes.Red, 5), new Rectangle(position, size));
                }
            }

            resultPbx.Image = inputImage;

            return result;
        }
        private void btnStart_Click(object sender, EventArgs e)
        {
            if (tmrScreenshots.Enabled)
            {
                tmrScreenshots.Enabled = false;
                btnStart.Text = "Start";
            }
            else
            {
                tmrScreenshots.Enabled = true;
                btnStart.Text = "Stop";
            }
        }
        private Bitmap ScreenShot()
        {
            Bitmap screenshot;
            screenshot = new Bitmap(currentScreen.Bounds.Width, currentScreen.Bounds.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
            // Create a graphics object from the bitmap
            Graphics gfxScreenshot = Graphics.FromImage(screenshot);
            // Take the screenshot from the upper left corner to the right bottom corner
            gfxScreenshot.CopyFromScreen(
                currentScreen.Bounds.X,
                currentScreen.Bounds.Y,
                0,
                0,
                currentScreen.Bounds.Size,
                CopyPixelOperation.SourceCopy);
            //testTesseract(screenshot);

            //SaveScreenshot(screenshot);
            MessageBox.Show(testTesseract(screenshot));
            return screenshot;
        }
        private string SaveScreenshot(Bitmap image)
        {
            string path = "";
            string directory = AppDomain.CurrentDomain.BaseDirectory + "Screens";
            path = directory + "\\Screenshot" + DateTime.Now.ToString("yyyy_MM_dd-hh_mm_ss") + ".png";
            if (Directory.Exists(directory))
            {
                image.Save(path, ImageFormat.Png);
            }
            else
            {
                Directory.CreateDirectory(AppDomain.CurrentDomain.BaseDirectory + "\\Screens");
            }
            return path;
        }
        //http://leonwoo-tech.blogspot.com/2018/06/tip-how-to-properly-setup-opencv-ocr-to.html
        private string testTesseract(Bitmap inputBmp)
        {
            string result = "";
            //To use this toImage you need : NuGet\Install-Package Emgu.CV.Bitmap -Version 4.5.5.4823
            inputBmp = PrepareImage(inputBmp);
            Image<Bgr, byte> emguImage = inputBmp.ToImage<Bgr, byte>();

            using (var image = emguImage)
            {
                using (Tesseract tesseractOcrProvider = new Tesseract(AppDomain.CurrentDomain.BaseDirectory + "\\Data", "eng", OcrEngineMode.Default))
                {
                    tesseractOcrProvider.SetImage(image);
                    tesseractOcrProvider.Recognize();
                    result = tesseractOcrProvider.GetBoxText().TrimEnd();
                }
            }
            //File.Delete(filePath);
            return result;
        }
        private void tmrScreenshots_Tick(object sender, EventArgs e)
        {
            //pbxInput.Image.Dispose();
            Image img = ScreenShot();
            pbxInput.Image = img;
            GC.Collect();
            //img.Dispose();
        }

        private void lsbScreens_SelectedIndexChanged(object sender, EventArgs e)
        {
            currentScreen = screens[lsbScreens.SelectedIndex];
        }

    }
}