Translate PDF into German

Extract and Translate PDF under Linux

This tutorial shows how to convert a PDF document (e.g., a French PDF) into searchable text using open-source tools on a Linux system and then translate it into German.

Prerequisites

• Linux system (Debian, LMDE, or any other distribution)
• Terminal access
• Installation of the following packages:
  • ocrmypdf
  • poppler-utils
  • tesseract-ocr-fra (French language for OCR)
  • tesseract-ocr-deu (German language, if needed for OCR)
  • translate-shell (for machine translation)
  • Optional: po4a and gettext tools for PO/POT workflow

1. Check if text can be directly extracted from the PDF

Open the PDF with a PDF reader (e.g., Evince, Okular) and try to select and copy text.

• If it works: Extract text directly
  pdftotext input.pdf dokument.txt

• If not (scanned PDF without text), proceed with OCR.

2. Run OCR on the PDF

OCR generates invisible text in the PDF that is searchable and extractable.

ocrmypdf -l fra input.pdf output_ocr.pdf

Explanation:

• -l fra indicates that the texts are in French (OCR language)
• input.pdf is your original PDF
• output_ocr.pdf is the new file with an embedded text layer

3. Extract text from the OCR PDF

Now you can extract the recognized text:

pdftotext output_ocr.pdf dokument.txt

The file dokument.txt contains the pure French text.

4. Machine translate the text into German

Translate the text using translate-shell:

trans -b :de -i dokument.txt -o dokument_de.txt

Parameters:

• -b: “Brief mode” (translates only the text, no additional info)
• :de: Target language German
• -i: Input file (here French text)
• -o: Output file (German translation)

5. Optional: Professional PO/POT workflow with po4a

For larger projects or better management, you can proceed as follows:

a) Create POT file from text

po4a-gettextize -f text -m dokument.txt -p dokument.pot

b) Create PO file for German

msginit --input=dokument.pot --locale=de --output=dokument-de.po

c) Edit .po file

Open dokument-de.po with a text editor or a tool like Poedit .

d) Transfer translation back to text format

po4a-translate -f text -m dokument.txt -p dokument-de.po -l dokument_de.txt

Summary of all commands

1. Install packages

sudo apt update

sudo apt install ocrmypdf poppler-utils tesseract-ocr-fra tesseract-ocr-deu translate-shell po4a gettext

2. Create OCR PDF (for scanned PDF)

ocrmypdf -l fra input.pdf output_ocr.pdf

3. Extract text from OCR PDF

pdftotext output_ocr.pdf dokument.txt

4. Translate text into German

trans -b :de -i dokument.txt -o dokument_de.txt

Optional: PO workflow

po4a-gettextize -f text -m dokument.txt -p dokument.pot msginit --input=dokument.pot --locale=de --output=dokument-de.po

Edit PO file…

po4a-translate -f text -m dokument.txt -p dokument-de.po -l dokument_de.txt

Notes

• OCR and translation quality may vary depending on the document.
• Locally installed solutions are preferred, especially for sensitive data.
• For GUI-based OCR, you can install and use gscan2pdf.
• The procedure is the same for all languages. For OCR, the respective language must be installed from which you want to translate.

Good luck with translating your PDF document!