How to detect angle of image containing text for OCR in emgucv csharp

See more:

C#

OCR

I am having govt pan card and i want to process that to get text details using tesseract and emgucv. My problem is how i will detect angle of text so that i can correct and pass to ocr.
Please find code below however it is less accurate.

Can you please check and suggest what should i do to improve it? any help will be highly appreciated?

What I have tried:

imgInput = new Image<Bgr, byte>(impath);
          Image<Gray, Byte> img2 = imgInput.Convert<Gray, Byte>();
          Bitmap imgs;
          Image<Gray, byte> imgout = imgInput.Convert<Gray, byte>().Not().ThresholdBinary(new Gray(50), new Gray(125));
          VectorOfVectorOfPoint contours = new VectorOfVectorOfPoint();
          Emgu.CV.Mat hier = new Emgu.CV.Mat();
          var blurredImage = imgInput.SmoothGaussian(5, 5, 0 , 0);
          CvInvoke.AdaptiveThreshold(imgout, imgout, 255, Emgu.CV.CvEnum.AdaptiveThresholdType.GaussianC, Emgu.CV.CvEnum.ThresholdType.Binary, 5, 45);

          CvInvoke.FindContours(imgout, contours, hier, Emgu.CV.CvEnum.RetrType.External, Emgu.CV.CvEnum.ChainApproxMethod.ChainApproxSimple);
          if (contours.Size >= 1)
          {
              for (int i = 0; i <= contours.Size; i++)
              {

                  Rectangle rect = CvInvoke.BoundingRectangle(contours[i]);
                  RotatedRect box = CvInvoke.MinAreaRect(contours[i]);
                  PointF[] Vertices = box.GetVertices();
                  PointF point = box.Center;
                  PointF edge1 = new PointF(Vertices[1].X - Vertices[0].X, Vertices[1].Y - Vertices[0].Y);
                  PointF edge2 = new PointF(Vertices[2].X - Vertices[1].X, Vertices[2].Y - Vertices[1].Y);
                  double r = edge1.X + edge1.Y;
                  double edge1Magnitude = Math.Sqrt(Math.Pow(edge1.X, 2) + Math.Pow(edge1.Y, 2));
                  double edge2Magnitude = Math.Sqrt(Math.Pow(edge2.X, 2) + Math.Pow(edge2.Y, 2));
                  PointF primaryEdge = edge1Magnitude > edge2Magnitude ? edge1 : edge2;
                  double primaryMagnitude = edge1Magnitude > edge2Magnitude ? edge1Magnitude : edge2Magnitude;
                  PointF reference = new PointF(1, 0);
                  double refMagnitude = 1;
                  double thetaRads = Math.Acos(((primaryEdge.X * reference.X) + (primaryEdge.Y * reference.Y)) / (primaryMagnitude * refMagnitude));
                  double thetaDeg = thetaRads * 180 / Math.PI;
                      imgInput = imgInput.Rotate(thetaDeg, new Bgr());
                      imgInput.Save(@"D:\workspace\EgmuCV\pan\image.jpg");
                      imgout = imgout.Rotate(box.Angle, new Gray());
                      imgout.Save(@"D:\workspace\EgmuCV\pan\image2.jpg");
                  Bitmap bmp = imgout.Bitmap;
                  break;
              }

          }