Manipulating a picture pdf

Question

Is there a practical tool to modify (with eraser and pen) a pdf file whose content is a scanned document or a picture taken by a digital camera? If so, which one is good?

Answer 1

Inkscape has some pdf support. Gimp has some support as well.

Answer 2

pdfimages is one program to extract images:

NAME
       pdfimages - Portable Document Format (PDF) image extractor (version 3.00)

SYNOPSIS
       pdfimages [options] PDF-file image-root

DESCRIPTION
       Pdfimages saves images from a Portable Document Format (PDF) file as Portable Pixmap (PPM), Portable Bitmap (PBM), or JPEG files.

       Pdfimages reads the PDF file PDF-file, scans one or more pages, and writes one PPM, PBM, or JPEG file for each image, image-root-
       nnn.xxx, where nnn is the image number and xxx is the image type (.ppm, .pbm, .jpg).


pdfimages --help
pdfimages version 0.12.4
Copyright 2005-2009 The Poppler Developers - http://poppler.freedesktop.org
Copyright 1996-2004 Glyph & Cog, LLC
Usage: pdfimages [options] <PDF-file> <image-root>
  -f <int>       : first page to convert
  -l <int>       : last page to convert
  -j             : write JPEG images as JPEG files
  -opw <string>  : owner password (for encrypted files)
  -upw <string>  : user password (for encrypted files)
  -q             : don't print any messages or errors
  -v             : print copyright and version info
  -h             : print usage information
  -help          : print usage information
  --help         : print usage information
  -?             : print usage information

pdftoppm is another one:

NAME
       pdftoppm - Portable Document Format (PDF) to Portable Pixmap (PPM) converter (version 3.00)

SYNOPSIS
       pdftoppm [options] PDF-file PPM-root

DESCRIPTION
       Pdftoppm  converts  Portable  Document  Format  (PDF) files to color image files in Portable Pixmap (PPM) format, grayscale image
       files in Portable Graymap (PGM) format, or monochrome image files in Portable Bitmap (PBM) format.

       Pdftoppm reads the PDF file, PDF-file, and writes one PPM file for each page, PPM-root-nnnnnn.ppm, where nnnnnn is the page  num‐
       ber.

As already mentioned, you can try to open a PDF with your graphic manipulation software.

As last fallback, you can display your PDF, take a screenshot, and work on that.

Answer 3

For modifying a pdf file whose content is scanned document you may install Xournal on your system.

If you have a Debian or Ubuntu-based system, open the terminal and enter this commandL sudo apt-get install xournal, or else install it through your synaptic package manager. For Fedora, use sudo yum install xournal.