...
- Save the code above in a file called "extract_text.sh"
- In the terminal, go to the directory where you saved extract_text.sh. For example:
- cd /Users/me/myscripts
- Make the script executable with the following command:
- chmod +x extract_text.sh
- Put all of your PDFs in a single directory.
- Assuming that you put all of your PDFs in /Users/me/mypdfs, and you want to write text output to the directory /Users/me/myplaintext, call extract_text.sh as follows:
- ./extract_text.sh /Users/me/mypdfs/ /Users/me/myplaintext/
- If you are working with German-language texts, you can add a language code at the end. For example:
- ./extract_text.sh /Users/me/mypdfs/ /Users/me/myplaintext/ deu
For OSX El Capitan
El Capitan introduced a feature called "System Integrity Protection" which makes it difficult to use pdftotext. If you want to skip that part and use only Tesseract, try the code below (courtesy of Christoph).
| Code Block | ||
|---|---|---|
| ||
#!/bin/bash
BPATH=$1 # Path to directory containing PDFs.
OPATH=$2 # Path to output directory.
LANG=$3 # See man tesseract > LANGUAGES
MIN_WORDS=5 # Number of words required to accept pdftotext result.
if [ $(echo "$LANG" | wc -c ) -lt 1 ] # Language defaults to eng.
then
LANG='eng'
fi
# If the output path does not exist, attempt to create it.
if [ ! -d "$OPATH" ]; then
mkdir -p "$OPATH"
fi
for FILEPATH in $BPATH*.pdf; do
# Extracts plain text content from a PDF.
#
# First, attempts to extract embedded text with pdftotext. If that fails,
# converts the PDF to TIFF and attempts to perform OCR with Tesseract.
#
# Path to text file to be created. E.g. ./myfile.txt
OUTFILE=$OPATH$(basename $FILEPATH).txt
touch "$OUTFILE" # The text file will be created regardless of whether
# text is successfully extracted.
# First attempt ot use pdftotext to extract embedded text.
#echo -n "Attempting pdftotext extraction..."
#pdftotext "$FILEPATH" "$OUTFILE"
#FILESIZE=$(wc -w < "$OUTFILE")
#echo "extracted $FILESIZE words."
# If that fails, try Tesseract.
#if [[ $FILESIZE -lt $MIN_WORDS ]]
# Nils Nilsson then
echo -n "Attempting OCR extraction..."
# Use imagemagick to convert the PDF to a high-rest multi-page TIFF.
convert -density 300 "$FILEPATH" -depth 8 -strip -background white \
-alpha off ./temp.tiff > /dev/null 2>&1
# Then use Tesseract to perform OCR on the tiff.
tesseract ./temp.tiff "$OUTFILE" -l $LANG > /dev/null 2>&1
# We don't need then intermediate TIFF file, so discard it.
rm ./temp.tiff
FILESIZE=$(wc -w < "$OUTFILE")
echo "extracted $FILESIZE words."
# fi
done |