Extracting text data from PDF files

Question

Is it possible to parse text data from PDF files in R? There does not appear to be a relevant package for such extraction, but has anyone attempted or seen this done in R?

In Python there is PDFMiner, but I would like to keep this analysis all in R if possible.

Any suggestions?

Answer 1

Linux systems have pdftotext which I had reasonable success with. By default, it creates foo.txt from a give foo.pdf.

That said, the text mining packages may have converters. A quick rseek.org search seems to concur with your crantastic search.

Answer 2

This is a very old thread, but for future reference: the pdftools R package extracts text from PDFs.

Answer 3

A colleague turned me on to this handy open-source tool: http://tabula.nerdpower.org/. Install, upload the PDF, and select the table in the PDF that requires data-ization. Not a direct solution in R, but certainly better than manual labor.

Answer 4

A purely R solution could be:

library('tm')
file <- 'namefile.pdf'
Rpdf <- readPDF(control = list(text = "-layout"))
corpus <- VCorpus(URISource(file), 
      readerControl = list(reader = Rpdf))
corpus.array <- content(content(corpus)[[1]])

then you'll have pdf lines in an array.

Answer 5

The tabula PDF table extractor app is based around a command line application based on a Java JAR package, tabula-extractor.

The R tabulizer package provides an R wrapper that makes it easy to pass in the path to a PDF file and get data extracted from data tables out.

Tabula will have a good go at guessing where the tables are, but you can also tell it which part of a page to look at by specifying a target area of the page.

Data can be extracted from multiple pages, and a different area can be specified for each page, if required.

For an example use case, see: When Documents Become Databases – Tabulizer R Wrapper for Tabula PDF Table Extractor.

Answer 6

install.packages("pdftools")
library(pdftools)


download.file("http://www.nfl.com/liveupdate/gamecenter/56901/DEN_Gamebook.pdf", 
              "56901.DEN.Gamebook", mode = "wb")

txt <- pdf_text("56901.DEN.Gamebook")
cat(txt[1])

Answer 7

I used an external utility to do the conversion and called it from R. All files had a leading table with the desired information

Set path to pdftotxt.exe and convert pdf to text

exeFile <- "C:/Projects/xpdfbin-win-3.04/bin64/pdftotext.exe"

for(i in 1:length(pdfFracList)){
    fileNumber <- str_sub(pdfFracList[i], start = 1, end = -5)
    pdfSource <- paste0(reportDir,"/", fileNumber, ".pdf")
    txtDestination <- paste0(reportDir,"/", fileNumber, ".txt")
    print(paste0("File number ", i, ", Processing file ", pdfSource))
    system(paste(exeFile, "-table" , pdfSource, txtDestination, sep = " "), wait = TRUE)
}