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https://github.com/abarker/pdfCropMargins

pdfCropMargins -- a program to crop the margins of PDF files
https://github.com/abarker/pdfCropMargins

crop cropper pdf pdf-converter pdf-document-processor python

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pdfCropMargins -- a program to crop the margins of PDF files

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README

        

==============
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:

.. image:: https://user-images.githubusercontent.com/1791335/63413846-9c9e3400-c3c8-11e9-90f5-6e429ae2d74b.gif
:width: 450px
:align: center
:alt: [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``.)

.. code-block:: sh

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:

.. code-block:: sh

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:

.. code-block:: sh

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

Windows
-------

The install command is:

.. code-block:: sh

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:

.. code-block:: sh

python -m 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:

.. code-block:: sh

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:

.. code-block:: sh

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

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

.. code-block:: sh

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:

.. code-block:: python

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:

.. code-block:: python

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
=============

.. In vim use this to get output:
:read !pdf-crop-margins -h

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.