OCR (optical character Recognizer)

private string Ocr(Bitmap image_s, bool isFull, bool isNum = false)
        {
            string temp = "";
            Image<Gray,byte> src = new Image<Gray,byte>(image_s);
            double ratio = 1;
            while (true)
            {
                ratio = (double)CvInvoke.cvCountNonZero(src) / (src.Width * src.Height);
                if (ratio > 0.5) break;
                src = src.Dilate(2);
            }
            Bitmap image = src.ToBitmap();

            TesseractProcessor ocr;
            if (isFull)
                ocr = full_tesseract;
            else if (isNum)
                ocr = num_tesseract;
            else
                ocr = ch_tesseract;

            int cou = 0;
            ocr.Clear();
            ocr.ClearAdaptiveClassifier();
            temp = ocr.Apply(image);
            while (temp.Length > 3)
            {
                Image<Gray, byte> temp2 = new Image<Gray, byte>(image);
                temp2 = temp2.Erode(2);
                image = temp2.ToBitmap();
                ocr.Clear();
                ocr.ClearAdaptiveClassifier();
                temp = ocr.Apply(image);
                cou++;
                if (cou > 10)
                {
                    temp = "";
                    break;
                }
            }
            return temp;

        }