[R] Doing PDF OCR with R

[Jeff Newmiller]

This code is using R like a command shell... there really is not much chance that R is the problem, and this is not a "tesseract" support forum, so this seems quite off-topic. 
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Sent from my phone. Please excuse my brevity.

On August 12, 2015 10:05:19 PM PDT, Anshuk Pal Chaudhuri <anshuk.p at motivitylabs.com> wrote:
>Hi All,
>
>I have been trying to do OCR within R (reading PDF data which data as
>scanned image). Have been reading about this @
>http://electricarchaeology.ca/2014/07/15/doing-ocr-within-r/
>
>This a very good post.
>
>Effectively 3 steps:
>
>convert pdf to ppm (an image format)
>convert ppm to tif ready for tesseract (using ImageMagick for convert)
>convert tif to text file
>The effective code for the above 3 steps as per the link post:
>
>lapply(myfiles, function(i){
>  # convert pdf to ppm (an image format), just pages 1-10 of the PDF
>  # but you can change that easily, just remove or edit the
>  # -f 1 -l 10 bit in the line below
>shell(shQuote(paste0("F:/xpdf/bin64/pdftoppm.exe ", i, " -f 1 -l 10 -r
>600 ocrbook")))
>  # convert ppm to tif ready for tesseract
>shell(shQuote(paste0("F:/ImageMagick-6.9.1-Q16/convert.exe *.ppm ", i,
>".tif")))
>  # convert tif to text file
>shell(shQuote(paste0("F:/Tesseract-OCR/tesseract.exe ", i, ".tif ", i,
>" -l eng")))
>  # delete tif file
>  file.remove(paste0(i, ".tif" ))
>  })
>The first two steps are happening fine. (although taking good amount of
>time, for 4 pages of a pdf, but will look into the scalability part
>later, first trying if this works or not)
>
>While running this, the first two steps work fine.
>
>While runinng the 3rd step, i.e
>
>**shell(shQuote(paste0("F:/Tesseract-OCR/tesseract.exe ", i, ".tif ",
>i, " -l eng")))**
>I having this error:
>
>Error: evaluation nested too deeply: infinite recursion /
>options(expressions=)?
>
>Or
>
>Tesseract is crashing.
>
>Any workaround or root cause analysis would be appreciated.
>
>Regards,
>Anshuk Pal Chaudhuri
>
>
>	[[alternative HTML version deleted]]
>
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