pdfScale.sh

Bash Script to scale PDFs from the command line.
Uses ghostscript to create a scaled version of the pdf input.
The “paper” size does not change, just the elements are resized.

Dependencies

The script uses basename, cat, grep, bc, head and gs (ghostscript).
You probably have everything installed already, except for ghostscript.
Optional dependencies are imagemagick, pdfinfo and mdls (Mac).

apt-get

sudo apt-get install ghostscript bc

yum

sudo yum install ghostscript bc

homebrew MacOS

brew install ghostscript

Optionals

From version 1.4.x I decided to create an adaptive method of getting the pagesize. It will try different methods if the previous one fails. People can also force a specific mode of operation with the -m parameter.

The order of operation is as follows:

1. Try to get /MediaBox with cat + grep
2. Failed AND MacOS ? Try mdls
3. Failed AND NOT MacOS ? Try pdfinfo
4. Failed ? Try ImageMagick’s identify
5. Failed ? Exit with error message

The cat+grep method will fail on PDFs without a /MediaBox.

You may install any of the above to be used in that case.

Help info

$ pdfscale -h
pdfscale v1.4.9

Usage: pdfscale [-v] [-s <factor>] [-m <mode>] <inFile.pdf> [outfile.pdf]
       pdfscale -h
       pdfscale -V

Parameters:
 -v          Verbose mode, prints extra information
             Use twice for even more information
 -h          Print this help to screen and exits
 -V          Prints version to screen and exits
 -m <mode>   Force a mode of page size detection 
             May disable the Adaptive Mode
 -s <factor> Changes the scaling factor, defaults to 0.95
             MUST be a number bigger than zero
             Eg. -s 0.8 for 80% of the original size 

Modes:
 a, adaptive  Default mode, tries all the methods below
 c, cat+grep  Forces the use of the cat + grep method
 m, mdls      Forces the use of MacOS Quartz mdls
 p, pdfinfo   Forces the use of Linux PdfInfo
 i, identify  Forces the use of ImageMagick's Identify

Notes:
 - Adaptive Page size detection will try different modes until
   it gets a page size. You can force a mode with -m 'mode'.
 - Options must be passed before the file names to be parsed.
 - The output filename is optional. If no file name is passed
   the output file will have the same name/destination of the
   input file, with .SCALED.pdf at the end (instead of just .pdf).
 - Having the extension .pdf on the output file name is optional,
   it will be added if not present.
 - Should handle file names with spaces without problems.
 - The scaling is centered and using a scale bigger than 1 may
   result on cropping parts of the pdf.

Examples:
 pdfscale myPdfFile.pdf
 pdfscale myPdfFile.pdf myScaledPdf
 pdfscale -v -v myPdfFile.pdf
 pdfscale -s 0.85 myPdfFile.pdf myScaledPdf.pdf
 pdfscale -m pdfinfo -s 0.80 -v myPdfFile.pdf
 pdfscale -v -v -m i -s 0.7 myPdfFile.pdf
 pdfscale -h

Example runs

$ pdfscale -m i -v -s 0.9 ../input.pdf 
pdfscale v1.4.9 - Verbose execution
Checking for ghostscript and bcmath
Checking for imagemagick's identify
  Scale factor: 0.9
    Input file: ../input.pdf
   Output file: ../input.SCALED.pdf
 Adaptive mode: Disabled
        Method: ImageMagick's Identify
         Width: 595 postscript-points
        Height: 842 postscript-points
 Translation X: 33.055225
 Translation Y: 46.777310

$ pdfscale -v -v -s 0.5 ../input-nup.pdf ../nuptest 
2017-02-22:07:56:38 | pdfscale v1.4.9 - Verbose execution
2017-02-22:07:56:38 | Checking for ghostscript and bcmath
2017-02-22:07:56:38 |   Scale factor: 0.5
2017-02-22:07:56:38 |     Input file: ../input-nup.pdf
2017-02-22:07:56:39 |    Output file: ../nuptest.pdf
2017-02-22:07:56:39 |  Adaptive mode: Enabled
2017-02-22:07:56:39 |         Method: Cat + Grep
2017-02-22:07:56:39 |                 Failed
2017-02-22:07:56:39 |         Method: Mac Quartz mdls
2017-02-22:07:56:39 |          Width: 842 postscript-points
2017-02-22:07:56:39 |         Height: 595 postscript-points
2017-02-22:07:56:39 |  Translation X: 421.000000
2017-02-22:07:56:39 |  Translation Y: 297.500000

System Install

The installer will name the executable as pdfscale with no uppercase chars and without the .sh extension.

If you have make installed you can use it to install to /usr/local/bin/pdfscale with:

sudo make install

To remove the installation use:

sudo make uninstall