How to prepare image to recognize by tesseract OCR

Question

I use Tesseract OCR to to extract meter reading... tesseract needs to recognize right white background and black numbers.. I tried to threshold image

src := cvLoadImage(filename,CV_LOAD_IMAGE_GRAYSCALE);


dst := cvCreateImage(cvGetSize(src), IPL_DEPTH_8U, 1);


cvThreshold(src, dst, 50, 250, CV_THRESH_BINARY);

but i didn't get the right result.. what should I do? I use deplhi6 with Delphi-OpenCV https://github.com/Laex/Delphi-OpenCV

Answer 1

You can treat this image as follows:

  for jy:= 0 to bm.Height do
   for ix := 0 to bm.Width do
    begin
      cor:=bm.Canvas.Pixels[ix,jy];

      R:=GetRValue(Cor);
      G:=GetGValue(Cor);
      B:=GetBValue(Cor);

      if g>38 then
        bm.Canvas.Pixels[ix,jy]:=clWhite
      else
        bm.Canvas.Pixels[ix,jy]:=clBlack;
    end;

As an output I got the following image:

Hope this helps.