Vicky, I may be able to convert your local-minima code to OpenCV code; can you send me the result files as well as the filter?
I wrote some Python code that uses OpenCV to crop the headstone images to show just the stone. Its not perfect, but it works OK. The Hough algorithm and the other corner-detection algorithms weren't working at all for me. So I just thresholded based on the average saturation value, row-by-row, column-by-column, to find a rectangle that was saturated enough. Then crop to that rectangle. Overly simple and dumb; however, it does somewhat work, whereas the other algorithms just gave me insane corners and didn't detect the headstone at all. Reference images: http://freepages.genealogy.rootsweb.ancestry.com/~janderse/cemeteries/Star%20of%20David%20Memorial%20Gardens/Garden%20of%20Haifa/ Thanks!! -Jon Andersen Software engineer Citrix Systems, Inc 954-973-4908 (home) On Mon, Feb 21, 2011 at 11:47 PM, Vicky Budhiraja <vicky.vi...@gmail.com>wrote: > Hi Jon, > > The code I have written is in MATLAB. Will you be able to convert it into > OpenCV code? Lemme know. > > In OpenCV if you apply simple thresholding, it should work. My method > (local-minima) is a little complicated (and accurate) then simple > thresholding. Therefore, hard to implement in C++ because of interpolation > step. I think OpenCV can do this, but we need to have a closer look for > this > step. > > Best Regards, > Vicky > > > -----Original Message----- > From: Jon Andersen [mailto:jande...@gmail.com] > Sent: Monday, February 21, 2011 23:42 > To: Vicky Budhiraja > Subject: Re: Image pre-processing for good OCR results > > Vicky, > > Thank you so much for responding! I appreciate your help with this > project. > > I have taken thousands of photos of headstones, and am trying to use > Tesseract on them. I will make the results available through > findagrave.com, so that people can search for their relatives. > > Here is a whole directory of sample images: > > http://freepages.genealogy.rootsweb.ancestry.com/~janderse/cemeteries/Star%2 > 0of%20David%20Memorial%20Gardens/Garden%20of%20Haifa/ > > Could you send me the code or results that you found? I am trying to > use OpenCV to do the image pre-processing. > > Thanks!!! > > -Jon > > Vicky Budhiraja wrote: > > Hi Jon, > > > > > > > > Like each morning, I check my emails and I saw those headstones Images > from > > Graves. I am a God fearing person. So, I was not able to ignore your > email. > > > > > > > > Regarding the preprocessing step, I suggest to apply Local Minima method > for > > background removal. However, you might require to adjust your window size > in > > order to achieve the best results. I did some experiments with the MATLAB > > code, and I got some good results. Testing on a larger sample set, may > > improve the step. > > > > > > > > Please tell me what project you are working on, maybe I will be able to > > contribute better? Just lemme know if you need any type of help! > > > > > > > > Best Regards, > > > > Vicky > > > > > > > > > > > > > > > > From: tesseract-ocr@googlegroups.com > [mailto:tesseract-ocr@googlegroups.com] > > On Behalf Of Jon Andersen > > Sent: Monday, February 21, 2011 07:32 > > To: tesseract-ocr@googlegroups.com > > Subject: Image pre-processing for good OCR results > > > > > > > > Hi, > > > > > > > > My project at http://RecordAGrave.com is about recording headstones from > > graves and posting the text and images on the Net so that people can > > research their family history. I would appreciate some advice on how to > > pre-process these headstone images to get the best results from Tesseract > > OCR. I have thousands of 1-2 MB jpg images of headstones to process. > > > > > > > > Example images: > > > > > > http://freepages.genealogy.rootsweb.ancestry.com/~janderse/cemeteries/Star%2 > > > > 0of%20David%20Memorial%20Gardens/Garden%20of%20Haifa%20-%20Raw/IMG_28215.jpg > > > > > > http://freepages.genealogy.rootsweb.ancestry.com/~janderse/cemeteries/Star%2 > > > > 0of%20David%20Memorial%20Gardens/Garden%20of%20Haifa%20-%20Raw/IMG_28216.jpg > > > > > > http://freepages.genealogy.rootsweb.ancestry.com/~janderse/cemeteries/Star%2 > > > > 0of%20David%20Memorial%20Gardens/Garden%20of%20Haifa%20-%20Raw/IMG_28217.jpg > > > > I am a software developer so I can script up pre-processing steps to > prepare > > the input for Tesseract. > > > > > > > > Any advice on improving OCR accuracy through pre-processing steps? > > > > > > > > Thanks so much, > > > > > > > > -Jon > > > > -- > > You received this message because you are subscribed to the Google Groups > > "tesseract-ocr" group. > > To post to this group, send email to tesseract-ocr@googlegroups.com. > > To unsubscribe from this group, send email to > > tesseract-ocr+unsubscr...@googlegroups.com. > > For more options, visit this group at > > http://groups.google.com/group/tesseract-ocr?hl=en. > > -- You received this message because you are subscribed to the Google Groups "tesseract-ocr" group. 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