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pdfCropMargins

The pdfCropMargins program is a command-line application to automatically crop the margins of PDF files. Cropping the margins can make it easier to read the pages of a PDF document -- whether the document is printed or displayed on a screen -- because the display fonts are larger. This program is similar to the Perl script pdfcrop except with many more options.

Features

  • Automatically detects the margins and can crop a given percentage of them.
  • Can crop all the pages to the same size to give a uniform appearance (such as in two-up).
  • Works on Linux, Windows, Cygwin, and OS X/Darwin.
  • Has an optional graphical user interface (GUI) for interactive cropping.
  • Renders and analyzes page images to find the bounding boxes, which allows it to deal with noisy scanned PDFs.
  • A rudimentary 'undo' capability is implemented by default.
  • Can crop pages uniformly based on the nth smallest crop values, which helps with noisy images or documents where a few pages have unwanted markings in their margins.
  • Can automatically run a document previewer on the output file.
  • The format of automatically-generated output-file names is easily modifiable.
  • Preserves document catalog information such as outlines if possible.
  • Crops rotated pages according to their appearance in the document viewer.
  • Can deal with at least simple cases of password-encrypted files.
  • Works with either MuPDF, the pdftoppm program, or the Ghostscript program to find the bounding boxes.
  • Can automatically apply a Ghostscript repair operation to attempt to fix corrupt PDF files.

This GIF shows the optional GUI, before and after cropping a document:

[GIF of pdfCropMargins]

What's New

See the CHANGELOG for recent changes and new features.

  • Version 2.1.4 extends the uniform and same page size options to allow selecting individual margins. The options are --uniform4 and --samePageSize4, which both take four characters of either 't' or 'f'. It also adds the --replaceOriginal option which is the same as --modifyOriginal but does not create a backup copy.
  • Version 2.1.2 has new options to center text on the pages after cropping. They are --centerText, --centerTextHoriz, --centerTextVert, and --centeringStrict.
  • New in version 2.0.1, the option --setSamePageSize (-ssp) allows a custom page box size to be passed in rather than having the program calculate the largest containing box size.

Installing

The easiest way to install the pdfCropMargins program is by using pip.

The basic features work out of the box, some of the options require either the external program pdftoppm or Ghostscript. For information on installing those programs on Linux and Windows, see: Installing pdftoppm and/or Ghostscript .

Linux/Ubuntu

If you are installing via pip with the --user option be sure $HOME/.local/bin is in your system PATH. (To install system-wide without --user the pip3 command below would need to be run with sudo.)

sudo apt install python3-tk
sudo apt install ghostscript poppler-utils # Optional, for ghostscript and pdftoppm.
pip3 install pdfCropMargins --user --upgrade

Troubleshooting: If you have problems with the install of PyMuPDF, the first thing to try is to upgrade your version of the pip program and then retry:

pip3 install pip --upgrade --user

If you still get an error "Failed building wheel for pymupdf" with the GUI install you can try forcing a binary install of PyMuPDF:

pip3 install pdfCropMargins --user --upgrade --only-binary pymupdf

Windows

The install command is:

pip install pdfCropMargins --upgrade

The pip program should be automatically installed along with Python. If you cannot find the pip executable you can usually run it like this:

python -m pip <arguments-to-pip>

Note that on some Windows installs the executable for Python is py rather than python.

In order for the command pdfcropmargins to work from the command line the Python bin directory must be on the Windows Path. The system-wide Python bin directory should already be on the path if you checked the box to modify Path when you installed Python; otherwise it should be added. (Note that if you install with the --user option to pip then you need to be sure that the local Python bin directory is in the Windows Path.)

Running

The program can be run 1) from the command line, 2) from the command line with a GUI, 3) from a Python program, or 3) from the source repo.

Running from the command line

After installation via pip the program can be run with either the command pdfcropmargins or the command pdf-crop-margins. For example:

pdfcropmargins -v -s -u your-file.pdf

That command prints verbose output, forces all pages to be the same size (-s) and then crops each page by the same amount (-u) for a uniform appearance, retaining the default of 10% of the margins. To run the same command with the GUI for fine-tuning, use:

pdfcropmargins -v -s -u -gui your-file.pdf

For help and to see the many command-line options that are available, run:

pdfcropmargins -h | more

The full output of that command is also listed below, at the bottom of this page. On Windows you may need to explicitly put the Python distribution's Scripts directory into your environment PATH in order to avoid having to use the full pathname.

Running with the GUI

To run the GUI, assuming that version of pdfCropMargins has been installed, just pass the -gui flag in addition to any other flags. The program is still a command-line application, and still respects all the flags, but the GUI lets you fine-tune the values of some of the command-line arguments such as the percent to crop, etc. The output filenames, etc., are all the same as for the command-line version. Options modifiable from the GUI are initially set to any values passed in on the command line.

The graphical display shows the effect of each crop when you hit the 'Crop' button. Multiple cropping calls for the same document tend to be faster because the PDF pages usually only need to be rendered to images one time.

Python interface

The program can also be called from a user's Python program (when the pdfCropMargins package is discoverable in the Python path). Just import the crop function and then call it with a list containing the usual command-line arguments as separate items. For example:

from pdfCropMargins import crop
crop(["-p", "20", "-u", "-s", "paper1.pdf"])
crop(["-p", "0", "-gui", "paper2.pdf"])

Any necessary exception handling should be performed by the calling code. The code may call sys.exit, so checking for SystemExit or BaseException may be required.

The crop function always returns four values, some of which may be set to None:

  • the output file path,
  • the exit code,
  • the text written to standard input,
  • the text written to standard output.

If the keyword argument string_io is set true (the default is false) then standard output and standard error streams are temporarily redirected to capture any output text as strings, which are returned as the final two arguments. Otherwise those values are set to None. The keyword argument quiet implies the string_io argument, but does not echo anything to the terminal while the crop function runs.

An example usage:

output_doc_pathname, exit_code, stdout_str, stderr_str = crop(
                         ["-p4", "0", "10", "0", "10", "paper2.pdf"],
                         string_io=True, quiet=False)

Running from the source distribution

The pdfCropMargins program can be run directly from the source code directory tree, provided the dependencies are installed. Just clone the repo and run the program pdfCropMargins.py located in the bin directory.

To pip install the program and its dependencies from the cloned repo rather than from PyPI just go to the root of the source directory and run pip install . (As usual, for code development use the -e option to make the code editable.)

Getting good crops

  • To diagnose unexpected crops, look at the pages with the smallest delta values, as indicated in the verbose (-v) output or at the bottom of the GUI. This tells you the page with the smallest crop amount for a margin.
  • Running without the -u or -s options will crop each page separately, so you can see which pages might be causing problems (such as pages with noise near the borders or margin text).
  • To get cropped pages all the same size be sure to use both -s to first make pages the same size and -u to crop each page by the same amount.
  • Sometimes a small pre-crop is needed (-ap or -ap4) to get past small, unwanted markings near the edges of pages.

Documentation

To see the documentation, run:

pdf-crop-margins -h | more

The output of that command follows:

Usage: pdfcropmargins [-h] [-o OUTFILE_PATH_OR_DIR] [-v] [-gui] [-p PCT]
                      [-p4 PCT PCT PCT PCT] [-pt] [-a BP] [-a4 BP BP BP BP]
                      [-cs] [-csm4 BP BP BP BP] [-ap BP] [-ap4 BP BP BP BP]
                      [-u] [-u4 {t,f} {t,f} {t,f} {t,f}] [-m INT]
                      [-m4 INT INT INT INT] [-mp INT] [-s]
                      [-s4 {t,f} {t,f} {t,f} {t,f}] [-ms INT]
                      [-ssp FLOAT FLOAT FLOAT FLOAT] [-e] [-g PAGESTR]
                      [-c [d|m|p|gr|gb|o]] [-gs] [-gsr] [-t BYTEVAL] [-nb INT]
                      [-ns INT] [-x DPI] [-y DPI] [-sr STR] [-gf INT]
                      [-b [m|c|t|a|b]] [-f [m|c|t|a|b]] [-r] [-A] [-gsf] [-nc]
                      [-pv PROG] [-mo] [-q] [-ro] [-nco] [-pf] [-sc STR]
                      [-su STR] [-ss STR] [-pw PASSWD] [-pc] [-khc] [-kvc]
                      [-spr FLOAT:FLOAT] [-prw FLOAT FLOAT FLOAT FLOAT] [-ct]
                      [-ch] [-cv] [-cst] [-i] [-pdl] [-gsp PATH] [-ppp PATH]
                      [--version] [-wcdf FILEPATH]
                      PDF_FILE [PDF_FILE ...]

Description:

     A command-line application to crop the margins of PDF files. Cropping
     the margins can make it easier to read the pages of a PDF document --
     whether the document is printed or displayed on a screen -- because the
     display fonts are larger. Margin-cropping is also sometimes useful when
     a PDF file is included in a document as a graphic.

     By default 10% of the existing margins will be retained; the rest will
     be eliminated. There are many options which can be set, however,
     including the percentage of existing margins to retain.

     Here is a simple example of cropping a file named document.pdf and
     writing the cropped output-document to a file named
     croppedDocument.pdf:

        pdfcropmargins document.pdf -o croppedDocument.pdf

     The alias 'pdf-crop-margins' can also be used to launch the program in
     place of 'pdfcropmargins'. If no destination is provided a filename
     will be automatically generated from the name of the source file (see
     below).

     The pdfCropMargins program works by changing the page sizes which are
     stored in the PDF file (and are interpreted by programs like Acrobat
     Reader). Both the CropBox and the MediaBox are set to the newly-
     computed cropped size. After this the view of the document in most
     programs will be the new, cropped view.

     In order to reduce the number of copies of a document which must be
     saved, a basic '--restore' option is provided. When cropping a file not
     produced by the pdfCropMargins program the default is to save the
     intersections of the MediaBox and any existing CropBox for each page as
     XML metadata. This saves the "usual" view of the original document in
     programs like Acrobat Reader. Subsequent crops of a file produced by
     pdfCropMargins do not by default alter the saved data. The restore
     option simply copies the saved values back to the MediaBox and CropBox.
     (Old versions of the program saved to the ArtBox; if these are cropped
     again the data is migrated to XML metadata.)

     Below are several examples using more of the command-line options, each
     applied to an input file called doc.pdf. The output filename is
     unspecified in most of these examples, so the program will
     automatically generate the filename (or an output filename can always
     be explicitly provided with '-o'):

     1) Crop doc.pdf so that all the pages are set to the same size and the
     cropping amount is uniform across all the pages (this gives a nice two-up
     appearance).  The default of retaining 10% of the existing margins is
     used.  Note carefully that '-u' only makes the amount to be cropped uniform
     for each page; if the pages do not have the same size to begin with they
     will not have the same size afterward unless the '-s' option is also used.

        pdfcropmargins -u -s doc.pdf

     2) Crop each page of doc.pdf individually (i.e., not uniformly), keeping 50%
     of the existing margins.

        pdfcropmargins -p 50 doc.pdf

     3) Crop doc.pdf uniformly, keeping 50% of the left margin, 20% of the bottom
     margin, 40% of the right margin, and 10% of the top margin.

        pdfcropmargins -u -p4 50 20 40 10 doc.pdf

     4) Crop doc.pdf retaining 20% of the margins, and then reduce the right page
     margins only by an absolute 12 points.

        pdfcropmargins -p 20 -a4 0 0 12 0 doc.pdf

     5) Add a constant 5bp around the bare bounding boxes on all pages (note the
     negative value passed to the `-a` option, which adds space rather than
     removing it).

        pdfcropmargins -p 0 -a -5 doc.pdf

     6) Pre-crop the document by 5bp on each side before computing the bounding
     boxes.  Then crop retaining 50% of the computed margins.  This can be
     useful for difficult documents such as scanned books with page-edge noise
     or other "features" inside the current margins.

        pdfcropmargins -ap 5 -p 50 doc.pdf

     7) Crop doc.pdf, re-naming the cropped output file to doc.pdf and backing
     up the original file in a file named backup_doc.pdf.

        pdfcropmargins -mo -pf -su "backup" doc.pdf

     8) Crop the margins of doc.pdf to 120% of their original size, increasing
     the margins.  Use Ghostscript to find the bounding boxes without explicit
     rendering by pdfCropMargins.

        pdfcropmargins -p 120 -c gb doc.pdf

     9) Crop the margins of doc.pdf ignoring the 10 largest margins on each edge
     (over the whole document).  This is especially good for noisy documents
     where all the pages have very similar margins, or when you want to ignore
     marginal annotations which only occur on a few pages.

        pdfcropmargins -m 10 doc.pdf

     10) Crop doc.pdf, launch the acroread viewer on the cropped output, and then
     query as to whether or not to rename the cropped file doc.pdf and back up
     the original file as doc_uncropped.pdf.

        pdfcropmargins -mo -q doc.pdf

     11) Crop pages 1-100 of doc.pdf, cropping all even pages uniformly and all odd
     pages uniformly.

        pdfcropmargins -g 1-100 -e doc.pdf

     12) Try to restore doc.pdf to its original margins, assuming it was cropped
     with pdfCropMargins previously.  Note that the default output filename is
     still named doc_cropped.pdf, even though it is the recovered file.  Use the
     '-mo' option to modify doc.pdf and backup the previous version.

        pdfcropmargins -r doc.pdf

     There are many different ways to use this program. After finding a
     method which works well for a particular task or workflow pattern it is
     often convenient to make a simple shell script (batch file) which
     invokes the program with those particular options and settings. Simple
     template scripts for Bash and Windows are packaged with the program, in
     the bin directory. The program can also be called from a user's Python
     program (when discoverable in the Python path) by using code such as

        from pdfCropMargins import crop
        crop(["-p", "20", "-u", "-s", "paper.pdf"])

     When printing a document with closely-cropped pages it may be necessary
     to use options such as "Fit to Printable Area". It may also be
     necessary to fine-tune the size of the retained margins if the edges of
     the text are being cut off.

     Sometimes a PDF file is corrupted or non-standard to the point where
     the routines used by this program raise an error and exit. In that case
     it can sometimes help to repair the PDF file before attempting to crop
     it. If it is readable by Ghostscript then the following command will
     often repair it sufficiently:

        gs -o repaired.pdf -sDEVICE=pdfwrite -dPDFSETTINGS=/prepress corrupted.pdf

     This command can also be used to convert some PostScript (.ps) files to
     PDF. The option '--gsFix' (or '-gsf') will automatically attempt to
     apply this fix, provided Ghostscript is available. See the description
     of that option for more information.

     The pdfCropMargins program handles rotated pages (such as pages in
     landscape mode versus portrait mode) as follows. All rotated pages are
     un-rotated as soon as they are read in. All the cropping is then
     calculated. Finally, as the crops are applied to the pages, the
     rotation is re-applied. This may give unexpected results in documents
     which mix pages at different rotations, especially with the '--uniform'
     or '--samePageSize' options. For rotated pages the arguments of all the
     options which take four arguments, one for each margin, are shifted so
     the left, bottom, right, and top margins correspond to the screen
     appearance (regardless of any internal rotation).

     All the command-line options to pdfCropMargins are described below. The
     following definition is useful in precisely defining what several of
     the options do. The "delta values" are the absolute reduction lengths,
     in points, which are applied to each original page to get the final
     cropped page. There is a delta value for each margin, on each page. In
     the usual case where all the margin sizes decrease, all the deltas are
     positive. A delta value can, however, be negative (e.g., when
     percentRetain > 100 or when a negative absolute offset is used). When a
     delta value is negative the corresponding margin size will increase.


Positional arguments:

  PDF_FILE     The pathname of the PDF file to crop. Use quotes around any
               file or directory name which contains a space. If no filename
               is given for the cropped PDF output file via the '-o' flag then
               a default output filename will be generated. By default it is
               the same as the source filename except that the suffix ".pdf"
               is replaced by "_cropped.pdf", overwriting by default if the
               file already exists. The file will be written to the working
               directory at the time when the program was run. If the input
               file has no extension or has an extension other than '.pdf' or
               '.PDF' then the suffix '.pdf' will be appended to the existing
               (possibly-null) extension. Globbing of wildcards and shell
               variable expansions are performed on the path.


options:
  -h, --help   Show this help message and exit.

  -o OUTFILE_PATH_OR_DIR, --outfile OUTFILE_PATH_OR_DIR
               An optional argument specifying the directory or file path that
               the cropped output document should be written to. If this
               option is not given the program will generate an output
               filename from the input filename and write to the current
               working directory. If only a directory is given the generated
               filename will be written in that directory instead. By default
               the string "_cropped" is appended to the input filename just
               before the file extension. (If the extension is not '.pdf' or
               '.PDF' then '.pdf' is also appended to the extension.) The
               options '--usePrefix', '--stringCropped' and '--
               stringSeparator' can be used to customize the generated
               filenames. By default any existing file with the same name will
               be silently overwritten; this can be avoided with the '--
               noclobber' option. Globbing of wildcards and shell variable
               expansions are performed on the directory path but not on the
               filename part. The output file path cannot be the same as the
               input document path (see instead the '--modifyOriginal'
               option).

  -v, --verbose
               Print more information about the program's actions and
               progress. Without this switch only warning and error messages
               are printed to the screen.

  -gui, --gui  Run the graphical user interface. This mode allows you to
               interactively preview and test different cropping options
               without having to recalculate the bounding boxes each time
               (which can be slow). All the usual command-line options to the
               program are still respected. Clicking the 'Crop' button in the
               GUI crops with the current settings, writing out a cropped PDF
               file to the same filename that the command-line version would
               write to. Note that successive changes to the margins in the
               GUI are not cumulative: settings are always applied to the
               original document as it was passed in to the program. The
               'Original' button reverts the display back to that original
               version.

  -p PCT, --percentRetain PCT
               Set the percent of margin space to retain in the image. This is
               a percentage of the original margin space. By default the
               percent value is set to 10. Setting the percentage to 0 gives a
               tight bounding box. Percent values greater than 100 increase
               the margin sizes from their original sizes, and negative values
               decrease the margins even more than a tight bounding box.

  -p4 PCT PCT PCT PCT, -pppp PCT PCT PCT PCT, --percentRetain4 PCT PCT PCT PCT
               Set the percent of margin space to retain in the image,
               individually for the left, bottom, right, and top margins,
               respectively. The four arguments should be percent values.
               Percent values greater than 100 increase the margin sizes from
               their original sizes, and negative values decrease the margins
               even more than a tight bounding box.

  -pt, --percentText
               Normally the percentage values passed to '--percentRetain' or '
               --percentRetain4' define the percentage of existing margins to
               retain. This flag alters the interpretation of those percent
               values. The margins are instead set to the given percentage of
               the text width or height. The left and right margins are set to
               a percentage of the bounding box width and the bottom and top
               margins are set to a percentage of the bounding box height.

  -a BP, --absoluteOffset BP
               Decrease each margin size by an absolute floating point offset
               value, to be subtracted from each margin's size after the
               'percentRetain' option is applied. The units are big points,
               bp, which is the unit used in PDF files. There are 72 bp in an
               inch. A single bp is approximately equal to a TeX point, pt
               (with 72.27pt in an inch). Negative values are allowed;
               positive numbers always decrease the margin size and negative
               numbers always increase it. Absolute offsets are always applied
               after any percentage change operations.

  -a4 BP BP BP BP, -aaaa BP BP BP BP, --absoluteOffset4 BP BP BP BP
               Decrease the margin sizes individually with four absolute
               offset values. The four floating point arguments should be the
               left, bottom, right, and top offset values, respectively. See
               the '--absoluteOffset' option for information on the units.

  -cs, --cropSafe
               Guarantee that all crops are safe in the sense that no crop
               ever goes beyond the tight bounding box on any margin. This
               does not apply to pre-crops using the '--absolutePreCrop'
               option. It also does not apply to any margins on pages where
               that margin is ignored due to the '--uniformOrderStat' or '--
               uniformOrderStat4' option. The latter effect works well with
               uniform cropping in the GUI: the value of 'uniformOrderStat'
               can be incremented for the margin with the minimum delta value
               (as seen by clicking that button) if no useful text would be
               cropped out. The '--cropSafeMin' option allows for modifying
               the minimum margin value, adding to the bounding box.

  -csm4 BP BP BP BP, --cropSafeMin4 BP BP BP BP
               The '--cropSafe' option will not perform any crops that cut
               into the bounding box. This option modifies the behavior of
               that option (assuming that `--cropSafe` is also selected).
               Instead of stopping at the bounding box, it will not crop past
               the bounding box plus the corresponding margin values passed
               in. This applies to all margins. The option takes four floats,
               in units of big points, for the left, bottom, right, and top
               margins, respectively. Negative values are allowed and allow
               some of the bounding box to be cropped.

  -ap BP, --absolutePreCrop BP
               This option is like '--absoluteOffset' except that it is
               applied before any bounding box calculations (or any other
               operations). The argument is the same, in units of bp. All
               successive operations are then relative to this pre-crop box,
               considered to be the full-page box. Note that since this
               absolute crop is applied before any bounding boxes are computed
               it is relative to the original full-page boxes of the document
               (unlike 'absoluteOffset', which is a crop relative to the
               newly-cropped margin after 'percentRetain' is applied). As a
               consequence, the number of points may need to be larger than
               what would work for 'absoluteOffset'. This option can be used
               to ignore text and markings out at the edge of the margins by
               cropping it out before the bounding boxes are calculated.

  -ap4 BP BP BP BP, --absolutePreCrop4 BP BP BP BP
               This is the same as '--absolutePreCrop' except that four
               separate arguments can be given. The four floating point
               arguments should be the left, bottom, right, and top absolute
               pre-crop values, respectively.

  -u, --uniform
               Crop all the pages uniformly. This forces the magnitude of
               margin-cropping (absolute, not relative) to be the same on each
               page. This option is applied after all the delta values have
               been calculated for each page, individually. Then all the left-
               margin delta values, for each page, are set to the smallest
               left-margin delta value over every page. The bottom, right, and
               top margins are processed similarly. Note that this effectively
               adds some margin space (relative to the margins obtained by
               cropping pages individually) to some of the pages. If the pages
               of the original document are all the same size then the cropped
               pages will again all be the same size. The '--samePageSize'
               option can be used in combination with this option to force all
               pages to be the same size after cropping.

  -u4 {t,f} {t,f} {t,f} {t,f}, --uniform4 {t,f} {t,f} {t,f} {t,f}
               This option is the same as '--uniform' except it is only
               applied to selected margins. The four arguments should be the
               characters 't' or 'f', to select (t) or deselect (f) the left,
               bottom, right, and top margins respectively.

  -m INT, --uniformOrderStat INT
               Choosing this option implies the '--uniform' option, but the
               smallest delta value over all the pages is no longer chosen.
               Instead, for each margin the nth smallest delta value (with n
               numbered starting at zero) is chosen over all the pages. The
               argument is the integer n, for example '-m 4'. Choosing n to be
               half the number of pages gives the median delta value. This
               option is useful for cropping noisy scanned PDFs which have a
               common margin size on most of the pages, or for ignoring
               annotations which only appear in the margins of a few pages.
               This option essentially causes the program to ignores the n
               largest tight-crop margins when computing common delta values
               over all the pages. Increasing n always either increases the
               cropping amount or leaves it unchanged. Some trial-and-error
               may be needed to choose the best number. Using '-m 1' tends to
               work well with arXiv papers (which have a date in the margin of
               the first page).

  -m4 INT INT INT INT, -mmmm INT INT INT INT, --uniformOrderStat4 INT INT INT INT
               This option is the same as '--uniformOrderStat' (or '-m')
               except that separate values are specified for each margin
               individually. The margins are ordered as left, bottom, right,
               and top.

  -mp INT, --uniformOrderPercent INT
               This option is the same as '--uniformOrderStat' except that the
               order number n is automatically set to a given percentage of
               the number of pages which are set to be cropped (either the
               full number or the ones set with '--pages'). This option
               overrides '--uniformOrderStat' if both are set. The argument is
               a float percent value; rounding is done to get the final order-
               number. Setting the percent to 0 is equivalent to n=1, setting
               the percent to 100 is equivalent to setting n to the full
               number of pages, and setting the percent to 50 gives the median
               (for odd numbers of pages).

  -s, --samePageSize
               Set all the page sizes to be equal. This option only has an
               effect when the page sizes are different. The pages sizes are
               set to the size of the union of all the page regions, i.e., to
               the smallest bounding box which contains all the pages. This
               operation is always done before any others (except '--
               absolutePreCrop'). The cropping is then done as usual, but note
               that any margin percentages (such as for '--percentRetain') are
               now relative to this new, possibly larger, page size. The
               resulting pages are still cropped independently by default, and
               will not necessarily all have the same size unless '--uniform'
               is also selected to force the cropping amounts to be the same
               for each page. If pages are selected with '--pages' then this
               option is only applied to those selected pages.

  -s4 {t,f} {t,f} {t,f} {t,f}, --samePageSize4 {t,f} {t,f} {t,f} {t,f}
               This option is the same as '--samePageSize' except it is only
               applied to selected margins. The four arguments should be the
               characters 't' or 'f', to either select (t) or deselect (f) the
               left, bottom, right, and top margins respectively.

  -ms INT, --samePageSizeOrderStat INT
               Choosing this option implies the '--samePageSize' option, but
               the calculations for each edge of the smallest bounding box
               ignore the largest (or smallest for left and bottom edges) n
               values. The argument is the nonnegative number n. Each edge is
               calculated independently. This is an order statistic for
               selecting the uniform size to make the pages. Note that this
               will cut off parts of some pages if n>0.

  -ssp FLOAT FLOAT FLOAT FLOAT, --setSamePageSize FLOAT FLOAT FLOAT FLOAT
               This option is like the '--samePageSize' option except the page
               size to set is passed in as four floating point arguments
               rather than being calculated. The numbers should represent the
               left, bottom, right, and top margin values, respectively. The
               origin is at the lower left. The numbers should be in points
               and are absolute, i.e., not relative to any current margins.
               The `--samePageSize` option will override this option if it is
               set.

  -e, --evenodd
               Crop all the odd pages uniformly, and all the even pages
               uniformly. The largest amount of cropping that works for all
               the pages in each group is chosen. If the '--uniform' ('-u')
               option is simultaneously set then the vertical cropping will be
               uniform over all the pages and only the horizontal cropping
               will differ between even and odd pages. See also the '--
               percentText' option which can be used for a similar effect.

  -g PAGESTR, -pg PAGESTR, --pages PAGESTR
               Apply the cropping operation only to the selected pages. The
               argument should be a list of the usual form such as
               "2-4,5,9,20-30". The page-numbering is assumed to start at 1.
               Ordering in the argument list is unimportant, negative ranges
               are ignored, and pages falling outside the document are
               ignored. Note that restore information is always saved for all
               the pages (in the ArtBox) unless '--noundosave' is selected.

  -c [d|m|p|gr|gb|o], --calcbb [d|m|p|gr|gb|o]
               Choose the method to calculate bounding boxes (or to render the
               PDF pages in order to calculate the boxes). The default option
               'd' will currently choose the MuPDF rendering option. The
               options to force a particular method are MuPDF ('m'), pdftoppm
               ('p'), or Ghostscript ('gr') for rendering, or direct
               Ghostscript bounding-box calculation ('gb'). For pdftoppm or
               Ghostscript options the corresponding program must be installed
               and locatable (see the path-setting options below if the
               default locator fails). Only the explicit rendering methods
               will work for scanned pages (see '--gsBbox'). Choosing 'o'
               reverts to the old default behavior of first looking for
               pdftoppm and then looking for Ghostscript for rendering.

  -gs, --gsBbox
               This option is maintained for backward compatibility; using '-c
               gb' is now preferred. Use Ghostscript to directly find the
               bounding boxes for the pages, with no explict rendering of the
               pages. (The default is to explicitly render the PDF pages to
               image files and calculate bounding boxes from the images.) This
               method tends to be much faster, but it does not work with
               scanned PDF documents. It also does not allow for choosing the
               threshold value, applying blurs, etc. Any resolution options
               are passed to the Ghostscript bbox device. This option requires
               that Ghostscript be available in the PATH as "gswin32c.exe" or
               "gswin64c.exe" on Windows, or as "gs" on Linux. When this
               option is set the Pillow image library for Python is not
               required.

  -gsr, --gsRender
               This is maintained for backward compatibility; using '-c gr' is
               now preferred. Use Ghostscript to render the PDF pages to
               images. By default the pdftoppm program will be preferred for
               the rendering, if it is found. Note that this option has no
               effect if '--gsBbox' is chosen, since then no explicit
               rendering is done.

  -t BYTEVAL, --threshold BYTEVAL
               Set the threshold for determining what is background space
               (white). The value can be from 0 to 255, with 191 the default
               (75 percent). This option may not be available for some
               configurations since the PDF must be internally rendered as an
               image of pixels. In particular, it is ignored when '--gsBbox'
               is selected. Any pixel value over the threshold is considered
               to be background (white), and any value below it is considered
               to be text (black). Lowering the value should tend to make the
               bounding boxes smaller. The threshold may need to be lowered,
               for example, for scanned images with greyish backgrounds. For
               pages with dark backgrounds and light text a negative threshold
               value can be used. In that case the absolute value is used as
               the threshold but the test is reversed to consider pixel values
               greater than or equal to the threshold to be background.

  -nb INT, --numBlurs INT
               When PDF files are explicitly rendered to image files, apply a
               blur operation to the resulting images this many times. This
               can be useful for noisy images.

  -ns INT, --numSmooths INT
               When PDF files are explicitly rendered to image files, apply a
               smoothing operation to the resulting images this many times.
               This can be useful for noisy images.

  -x DPI, --resX DPI
               The x-resolution in dots per inch to use when the image is
               rendered to find the bounding boxes. The default is 150. Higher
               values produce more precise bounding boxes but require more
               time and memory.

  -y DPI, --resY DPI
               The y-resolution in dots per inch to use when the image is
               rendered to find the bounding boxes. The default is 150. Higher
               values produce more precise bounding boxes but require more
               time and memory.

  -sr STR, --screenRes STR
               Pass in an X-windows style geometry string for the GUI to use
               as the fullscreen resolution and for the upper-left placement
               of the window. This is mainly for when the screen-size
               detection algorithm fails for a particular system. For example,
               with a screen of size "1024x720" that string should be used
               with the option. To also place the window at (0,0) the string
               would be "1024x728+0+0". See also the '--guiFontSize' option
               which can be used to decrease the overall size of the GUI
               window.

  -gf INT, --guiFontSize INT
               Choose the GUI font size. Making this smaller than the default
               of 11 can also make the GUI smaller if it does not fit on a
               smaller monitor.

  -b [m|c|t|a|b], --boxesToSet [m|c|t|a|b]
               By default the pdfCropMargins program sets the MediaBox for
               each page of the cropped PDF document to the new, cropped page
               size. This default setting is usually sufficient, but this
               option can be used to select different PDF boxes to set. The
               option takes one argument, which is the first letter
               (lowercase) of a type of box. The choices are MediaBox (m),
               CropBox (c), TrimBox (t), ArtBox (a), and BleedBox (b). This
               option overrides the default and can be repeated multiple times
               to set several box types. Note that the program now uses
               PyMuPDF to set the boxes, and it will refuse to set any non-
               MediaBox boxes unless they are fully contained in the MediaBox.
               In that case a warning will be issued and the box will not be
               set.

  -f [m|c|t|a|b], --fullPageBox [m|c|t|a|b]
               By default the program first (before any cropping is
               calculated) sets the MediaBox of each page in (a copy of) the
               document to the intersection of its previous MediaBox and
               CropBox. This ensures that the cropping is relative to the
               usual document-view in programs like Acrobat Reader. This
               essentially defines what is assumed to be the full size of
               pages in the document, and all cropping is then performed
               relative to that full-page size. This option can be used to
               alternately use the MediaBox, the CropBox, the TrimBox, the
               ArtBox, or the BleedBox in defining the full-page size. The
               option takes one argument, which is the first letter
               (lowercase) of the type of box to use. If the option is
               repeated then the intersection of all the box arguments is
               used. Only one choice is allowed in combination with the '-gs'
               option since Ghostscript does its own internal rendering when
               finding bounding boxes. The default with '-gs' is the
               CropBox.

  -r, --restore
               This is a simple undo operation which essentially undoes all
               the crops ever made by pdfCropMargins and returns to the
               original margins (provided no other program modified the saved
               XML data for the pdfCropMargins key). By default, whenever this
               program crops a file for the first time it saves the MediaBox
               intersected with the CropBox for each page as XML metadata. The
               XML metadata is is checked to see if there is any existing
               restore data. If so, the saved metadata for each page is simply
               copied to the MediaBox and the CropBox for the page. This
               restores the earlier view of the document, such as in Acrobat
               Reader (but does not completely restore the previous condition
               in cases where the MediaBox and CropBox differed). Any options
               such as '-u', '-p', and '-a' which do not make sense in a
               restore operation are ignored. Note that as far as default
               filenames the operation is treated as just another crop
               operation (the default-generated output filename still has a
               "_cropped.pdf" suffix). The '--modifyOriginal' option (or its
               query variant) can be used with this option. Saving restore
               data as XML metadata can be disabled by using the '--
               noundosave' option.

  -A, --noundosave
               Do not save any restore data as XML metadata. Note that the '--
               restore' operation will not work correctly for the cropped
               document later if this option is included in the cropping
               command.

  -gsf, --gsFix
               Attempt to repair the input PDF file with Ghostscript before it
               is read-in. This requires that Ghostscript be available. (See
               the general description text above for the actual command that
               is run.) This can also be used to automatically convert some
               PostScript files (.ps) to PDF for cropping. The repaired PDF is
               written to a temporary file; the original PDF file is not
               modified. The original filename is treated as usual as far as
               automatic name-generation, the '--modifyOriginal' option, and
               so forth. This option is often helpful if the program hangs or
               raises an error due to a corrupted PDF file. Note that when re-
               cropping a file already cropped by pdfCropMargins this option
               is probably not necessary, and if it is used in a re-crop (at
               least with current versions of Ghostscript) it will reset the
               Producer metadata which the pdfCropMargins program uses to tell
               if the file was already cropped by the program (so the '--
               restore' option will not work in combination with this option).
               This option is not recommended as something to use by default
               unless you encounter many corrupted PDF files and do not need
               to restore back to the original margins.

  -nc, --noclobber
               Never overwrite an existing file with the cropped output
               file.

  -pv PROG, --preview PROG
               Run a PDF viewer on the cropped PDF output. The viewer process
               is run in the background. The viewer is launched after
               pdfCropMargins has finished all the other options. The only
               exception is when the '--queryModifyOriginal' option is also
               selected. In that case the viewer is launched before the query
               so that the user can look at the output before deciding whether
               or not to modify the original. (Note that answering 'y' will
               then move the file out from under the running viewer; close and
               re-open the file before adding annotations, highlighting, etc.)
               The single argument should be the path of the executable file
               or script to run the chosen viewer. The viewer is assumed to
               take exactly one argument, a PDF filename. For example, on
               Linux the Acrobat Reader could be chosen with /usr/bin/acroread
               or, if it is in the PATH, simply acroread. A shell script or
               batch file wrapper can be used to set any additional options
               for the viewer.

  -mo, --modifyOriginal
               This option moves (renames) the original document file to a
               backup filename and then moves the cropped file to the original
               document's filename (and directory path). Thus it effectively
               crops the original document file in-place and makes a backup
               copy of the original file in the output directory. The backup
               filename for the original document is always generated from the
               original filename; any prefix or suffix which would be added by
               the program to generate a filename (by default a "_cropped"
               suffix) is modified accordingly (by default to "_uncropped").
               The '--usePrefix', '--stringUncropped', and '--stringSeparator'
               options can all be used to customize the generated backup
               filename. If an output path is specified via the '--outfile'
               ('-o') option then the backup document is written to that
               pathname (in the same directory the cropped file was first
               written to if only a filename is provided). This operation is
               performed last, so if a previous operation fails the original
               document will be unchanged. Be warned that running
               pdfCropMargins twice on the same source path with this option
               will modify the backed-up original file; the '--
               noclobberOriginal' option can be used to avoid this.

  -q, --queryModifyOriginal
               This option selects the '--modifyOriginal' option, but queries
               the user about whether to actually do the final move operation.
               This works well with the '--preview' and/or '--gui' options: if
               the preview looks good you can opt to modify the original file
               (keeping a copy of the original). If you decline then the files
               are not swapped (and are just as if the '--modifyOriginal'
               option had not been set).

  -ro, --replaceOriginal
               This option implies the '--modifyOriginal' option and works the
               same except that no backup copy is made. The original file is
               deleted and the cropped file is moved to the original filename.
               This option can be used in combination with the '--
               queryModifyOriginal' and works the same except that the
               original file is replaced, without a backup copy.

  -nco, --noclobberOriginal
               If the '--modifyOriginal' option is selected, do not ever
               overwrite an existing file as the backup copy for the original
               file. This essentially does the move operations for the '--
               modifyOriginal' option in noclobber mode, and prints a warning
               if it fails. On failure the result is exactly as if the '--
               modifyOriginal' option had not been selected. This option is
               redundant if the ordinary '--noclobber' option is also set.

  -pf, --usePrefix
               Prepend a prefix-string when generating default file names
               rather than appending a suffix-string. The same string value is
               used, either the default or the one set via the '--
               stringCropped' or '--stringUncropped' option. With the default
               values for the other options and no output file specified, this
               option causes the cropped output for the input file
               "document.pdf" to be written to the file named
               "cropped_document.pdf" (instead of to the default filename
               "document_cropped.pdf").

  -sc STR, --stringCropped STR
               This option can be used to set the string which will be
               appended (or prepended) to the document filename when
               automatically generating the output filename for a cropped
               file. The default value is "cropped".

  -su STR, --stringUncropped STR
               This option can be used to set the string which will be
               appended (or prepended) to the document filename when
               automatically generating the output filename for the original,
               uncropped file. The default value is "uncropped".

  -ss STR, --stringSeparator STR
               This option can be used to set the separator string which will
               be used when appending or prepending string values to
               automatically generate filenames. The default value is "_".

  -pw PASSWD, --password PASSWD
               Specify a password to be used to decrypt an encrypted PDF file.
               Note that decrypting with an empty password is always tried, so
               this option is only needed for non-empty passwords. The
               resulting cropped file will not be encrypted, so use caution if
               important data is involved.

  -pc, --prevCropped
               Test whether or not the document was previously cropped with
               the pdfCropMargins program. If so, exit with exit code 0. If
               not, exit with exit code 1. This option is intended mainly for
               scripting, for example to only crop documents that have not
               been previously cropped. Requires a document filename option.
               No other options are honored when this option is selected
               except '--gsFix', '--version', and '--help'.

  -khc, --keepHorizCenter
               This option keeps the horizontal center point of a PDF fixed.
               The usual crops are calculated, but for each page the left and
               right delta values are both set to the smallest of the two
               values (so the cropping amount is the same on each side). This
               option does not apply to pre-crops.

  -kvc, --keepVertCenter
               This option keeps the vertical center point of a PDF fixed. The
               usual crops are calculated, but for each page the upper and
               lower delta values are both set to the smallest of the two
               values (so the cropping amount is the same on the top and
               bottom). This option does not apply to pre-crops.

  -spr FLOAT:FLOAT, --setPageRatios FLOAT:FLOAT
               Force all the cropped page ratios to equal the given ratio. All
               crops are calculated and applied as usual, but either the left
               and right margins will be increased equally or else the top and
               bottom margins will be increased equally in order to make the
               ratio of width to height equal the set value. Margins are only
               ever increased. The format for the ratio is either a string
               width-to-height ratio such as '4.5:3' or else a floating point
               number like '0.75' which is the width divided by the height.
               This option can be useful in some PDF viewers.

  -prw FLOAT FLOAT FLOAT FLOAT, --pageRatioWeights FLOAT FLOAT FLOAT FLOAT
               This option weights any whitespace added by the '--
               setPageRatios' argument. It takes four weight arguments, one
               per margin. The four floating point arguments should be the
               left, bottom, right, and top weights, respectively. The weights
               determine what proportion of the total height(width) increase
               necessary to achieve the target page ratio is added to the
               corresponding margin. All weights must be greater than zero.

  -ct, --centerText
               Center the text horizontally and vertically after cropping. The
               crop for each page is adjusted so that the tight bounding box
               is centered in the page (if possible). If an order statistic
               method like '--uniformOrderStat' is applied then, for ignored
               edges, the bounding box edge that was actually used to
               calculate the crop values is used. If the '--centeringStrict'
               flag is set then each page will be centered regardless of any
               order statistic calculation.

  -ch, --centerTextHoriz
               This is the same as '--centerText' except pages are only
               centered horizontally.

  -cv, --centerTextVert
               This is the same as '--centerText' except pages are only
               centered vertically.

  -cst, --centeringStrict
               This flag modifies the behavior of bounding-box-centering
               options like '--centerText'. Normally pages ignored for order
               statistic operations like '--uniformOrderStat' are also ignored
               for centering and the page actually used for cropping is used
               for centering. This option forces strict centering of each
               page.

  -i, --showImages
               When explicitly rendering PDF files to image files, display the
               inverse image files that are used to find the bounding boxes.
               Useful for debugging and for choosing some of the other
               parameters (such as the threshold). This option requires a
               default external viewer program selected by the Pillow image
               manipulation package (xv on Unix, and usually Paint on
               Windows).

  -pdl, --pdftoppmLocal
               This option is deprecated. Use a locally-packaged pdftoppm
               executable rather than the system version. This option is only
               available on Windows machines; it is ignored otherwise. By
               default the first pdftoppm executable found in the directories
               in the PATH environment variable is used. On Windows the
               program will revert to this option if PDF image-rendering is
               required, PyMuPDF is not installed, and no system pdftoppm or
               Ghostscript executable can be found.

  -gsp PATH, --ghostscriptPath PATH
               Pass in a pathname to the ghostscript executable that the
               program should use. No globbing is done. Useful when the
               program is in a nonstandard location.

  -ppp PATH, --pdftoppmPath PATH
               Pass in a pathname to the pdftoppm executable that the program
               should use. No globbing is done. Useful when the program is in
               a nonstandard location.

  --version    Return the pdfCropMargins version number and exit immediately.
               All other options are ignored.

  -wcdf FILEPATH, --writeCropDataToFile FILEPATH
               Write out the calculated list of crops to the file with the
               file pathname that is passed in and exit. Mostly used for
               automated testing and debugging.


The pdfCropMargins program is Copyright (c) 2014 by Allen Barker.
Released under the GNU GPL license, version 3 or later.