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?
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.
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.