Implemented slice

[paperjam.git] / paperjam.1.txt

PAPERJAM(1)
===========

NAME
----
paperjam - a PDF document processor

SYNOPSIS
--------
*paperjam* 'options' 'commands' 'input' 'output'

DESCRIPTION
-----------
PaperJam is a tool for transform PDF files. It can re-order pages, scale
and rotate them, put multiple pages on a single sheet, draw cropmarks,
and many other tricks.

PaperJam takes an input file, splits it to a list of pages, applies a sequence
of commands on this list, and finally writes the results to an output file.

For each page, PaperJam tracks two sets of dimensions: the width and height
of the 'physical page' (paper), and the 'image box', which is a rectangle on the
physical page containing all useful contents. Initially, the physical
page is equal to the *CropBox* of the PDF page and the image box to its
*ArtBox* (which is optional and it defaults to the *CropBox*). Further
commands can modify these dimensions.

OPTIONS
-------
*-b, --bbox*::
        Recalculate image box of each page to enclose the contents really
        drawn on the page. This is done by asking GhostScript to render each
        page.

*-d, --debug*::
        Show debugging messages. Increases verbosity when given multiple times.

*--help*::
        Show help on options and commands.

GENERAL SYNTAX
--------------
PaperJam takes a list of commands separated by spaces, like this:

        paperjam 'common scaleto("a4") nup(2, hspace=5mm)' in.pdf out.pdf

Each command starts with its identifier (a sequence of alphanumeric characters,
underscores, and dashes, which begins with a letter). Then come arguments enclosed
in parentheses. All arguments can be written as 'name'='value' (where the name is
an identifier). For some of them, the name can be omitted and the meaning
follows from the position in the argument list (hence these are called
'positional' arguments).

There are several types of arguments:

numbers::
        Ordinary decimal numbers, possibly fractional.

dimensions::
        Numbers with a unit of length. We support these units:
        mm, cm, dm, m, in (inch), pt (printers' point, that is 1/72 in).

strings::
        Strings written in double quotes. If you want to include the double
        quote character or a backslash in the string, precede it with a backslash.
        For convenience, the double quotes can be omitted if the string value
        satisfies the syntax of an identifier. In case of positional arguments,
        the identifier must not match the name of any argument. Please avoid
        using this shortcut in scripts, because they could be easily broken
        by parameters introduced in newer versions of PaperJam.

switches::
        Boolean value: either 0 (false) or 1 (true). If only the name is given (with no value
        and no equal sign), the switch is set to true.

Pipelines
~~~~~~~~~
Several commands apply other commands on a subset of pages. This is usually
described by a 'pipeline' like:

        { 1: rotate(90), 2: flip(h) flip(v) }
        { 1..10: common }
        { 1 2, 11..20, 30..21 }

The pipeline is enclosed in curly braces. It consists of one or more 'stages'
separated by commas. Each stage has one or more 'page selectors' (page numbers
or ranges) and an optional list of commands to apply on these pages (separated
from the selectors by a semicolon).

When a range is written backwards (the first page number is greater than the
second one), the pages are processed in reverse order.

Paper formats
~~~~~~~~~~~~~
When a paper format is expected, it is given either by its width and height
(the corresponding arguments are usually called *w* and *h*), or by the standard
name of the format (called *paper*). PaperJam currently uses the libpaper library
for parsing the names. You can call +paperconf -a+ to get the list of known names.

Margins
~~~~~~~
Many commands take a specification of margins on all sides of an image.
You can set either a common value for all margins, or two values for vertical
and horizontal margins, or separate values for all margins. You can also
combine these ways: for example you can set a horizontal, top, and bottom
margin.

More formally, there are 7 arguments controlling margins: common,
horizontal, vertical, left, right, top, and bottom. Horizontal and vertical
default to common, left and right default to horizontal, top and bottom default
to vertical.

Positioning
~~~~~~~~~~~
Multiple commands involve positioning an image on a larger page. The image
is placed according to a two-letter position specification (usually an argument
called *pos*). The first letter specifies vertical placement: *t* for top,
*c* for center, *b* for bottom. The second one horizontal placement: *l* for left,
*c* for center, *r* for right.

COMMANDS
--------
PaperJam knows the following commands and arguments. Positional arguments
have their names enclosed in square brackets.

add-blank
~~~~~~~~~
Add blank page(s) after each page.

*[n=]*'int'::
        The number of blank pages to add. Defaults to 1.

*[paper=]*'string', *w=*'dimen', *h=*'dimen'::
        Paper size of the blank pages (see Paper formats above).

apply
~~~~~
Applies commands on a sub-set of pages:

        apply { 1: rotate(90), 2: flip(h) }

Takes a pipeline. For each input page, it finds the pipeline stage
matching the page index (its position in the input document, starting with 1)
and applies the commands in the stage on the page. If no stage matches,
the page is left unchanged. If multiple stages match, the first one wins.

book
~~~~
Prepares booklets (also known as signatures) for book binding.
With no argument, it re-orders pages in the document, so that a subsequent
*nup(2)* produces the correct booklet layout: two pages on one sheet
and when the document is printed double-sided and folded in half,
you have a booklet. If the number of input pages is not divisible by 4,
blank pages are added.

*[n=]*'int'::
        Split the document in parts per 'n' pages and produce a separate
        booklet from each part. The 'n' must be divisible by 4.

clip
~~~~
Suppress page contents drawn outside the image box.

*bleed=*'dimen'::
        Let the image bleed this far outside the image box.
        (Technically, it sets the crop box to the image box enlarged
        at all sides by this amount.)

common
~~~~~~
Use a common page size and image box for all pages. More specifically,
the new page width and height are set to the maximum of all page widths
and heights and the new image box to the minimal rectangle containing all
image boxes.

cropmarks
~~~~~~~~~
Draw cropping marks around the image box.

*mark=*'string'::
        Set cropmark style:
        *box* for a rectangle around the image box,
        *cross* for crosses in the corners of the box,
        *in* for two arms of a cross in each corner, pointing inwards,
        *out* for two arms pointing outwards,
        *bg* for drawing a filled rectangle under the box.

*pen=*'dimen'::
        Pen width for drawing cropmarks (for all styles except bg).
        Default: 0.2 pt.

*len=*'dimen'::
        Cropmark arm length (for cross, in, out).
        Default: 5 mm.

*offset=*'dimen'::
        Draw cropmarks around image box enlarged by this distance
        on all sides.

*color=*'string'::
        Cropmark color, given as RRGGBB in hexadecimal.
        Default: +000000+ (black).

debug
~~~~~
Draw debugging information on each page: a red rectangle around the page,
a green rectangle around the image box.

expand
~~~~~~
Expand paper around the image. Recalculates paper size and the position
of the image on the paper, so that the distance between each edge of the
image box and the corresponding edge of the paper increases by the given
amount.

*[by=]*'dimen'::
        Adjust all margins by the same amount. Defaults to 0.

*h=*'dimen', *v=*'dimen', *l=*'dimen', *r=*'dimen', *t=*'dimen', *b=*'dimen'::
        Adjust horizontal, vertical, left, right, top, and bottom margins.
        See Margins above to see how these argument interact with each other.

fit
~~~
If a paper size is given, scale and translate the image to fit on the
paper (with given margins). If no paper is given, set the paper size
and the position of the image according to the margins.

If the paper and the image have different aspect ratios, the *pos*
argument controls the position of the image on the paper.

*[paper=]*'string', *w=*'dimen', *h=*'dimen'::
        Paper format, or paper width and height (see Paper formats above
        for details).

*pos=*'string'::
        Specify position of the image on the paper (see Positioning above).
        Defaults to *cc*.

*margin=*'dimen', *hmargin=*'dimen', *vmargin=*'dimen', *lmargin=*'dimen', *rmargin=*'dimen', *tmargin=*'dimen', *bmargin=*'dimen'::
        Set margins (see Margins above). Defaults to 0.

flip
~~~~
Flip pages horizontally or vertically.

*h=*'switch'::
        Flip horizontally.

*v=*'switch'::
        Flip vertically.

margins
~~~~~~~
Define a new image box by dimensions of margins around it. More technically,
the new image box is calculated from the page box by shrinking it by the appropriate
margin on each side.

*[size=]*'dimen'::
        Set all margins at once.

*h=*'dimen', *v=*'dimen', *l=*'dimen', *r=*'dimen', *t=*'dimen', *b=*'dimen'::
        Set margins (see Margins above). Defaults to *size*.

merge
~~~~~
Merge all pages to one by placing them one over another. (The first page is drawn
first.)

modulo
~~~~~~
Act on n-tuples of pages.
The document is split to n-tuples (the partial n-tuple at the end is padded with
blank pages, whose size matches the first page of the n-tuple).
A pipeline is then run separately for each n-tuple, selecting pages from the tuple
and applying commands on them.

More specifically, the stages of the pipeline are processed from the left to the
right. Each stage forms a temporary document by taking the selected pages from the n-tuple
(numbered from 1 to n). Then it applies the commands on this document and appends the
result to the end of the output of the whole modulo.

Negative page numbers can be also used, which adresses pages in the "mirror-image
tuple". Page number -'i' in tuple 'j' corresponds to page 'i' in the 'j'-th tuple
from the end of the document.

Arguments:

*[n=]*'int' (mandatory)::
        Number of pages in a single tuple.

*half=*'switch'::
        Process only the first half of n-tuples. This is often used in conjunction
        with negative page numbers.

For example, the following command rotates every other page:

        modulo(2) { 1, 2: rotate(180) }

While this command skips every other page:

        modulo(2) { 1 }

move
~~~~
Shift contents on the page. Paper size does not change, the image box moves.

*[x=]*'dimen', *[y=]*'dimen'::
        Move everything right/up by the given distance.

null
~~~~
Do nothing.

nup
~~~
Combine multiple pages to one (n-up printing). Allows detailed control over the
parameters, but if only a subset of the parameters is given (in the most trivial case,
just the number of pages to put on a single sheet), the remaining parameters are
adjusted to maximize coverage of the sheet.

For example, when the input document is typeset on A4 paper,
+nup(2)+ rotates pages by 90 degrees, scales them to 70.7% size,
and puts them side-by-side. On the same input, +nup(4)+ produces
the same as +nup(2,2)+, that is a two-by-two grid of pages scaled
to 50%.

Technically, nup first splits the input document to n-tuples of pages
(padding the last incomplete n-tuple with blank pages of the size of the
first page of that n-tuple). For each n-tuple, it creates an output page,
splits it to a grid-like arrangement of tiles, and scales and/or rotates
each page to fit in its tile.

*[n=]*'number'::
        If *m* is also given, *n* is the number of rows of the grid of tiles.
        Without *m*, the total number of tiles on a page.

*[m=]*'number'::
        The number of columns of the grid of tiles.

*by=*'string'::
        Tile filling order: *rows* (default) fills rows from the top to the bottom,
        inside each row from the left to the right; *cols* fills columns from
        the left to the right, inside each column from the top to the bottom;
        *tile* copies the same page to all tiles.

*crop=*'switch'::
        Crop input pages to their image box. (By default, *nup* places the input
        papers in tiles. With this option, it places the image boxes in tiles,
        effectively cutting away original margins.)

*mixed=*'switch'::
        By default, *nup* adjusts all input pages to a common paper size and
        image box size (like the *common* command does). This switch disables
        that.

*rotate=*'switch'::
        Specify if the pages should be rotated. Default: choose automatically.

*scale=*'number'::
        Scaling factor. Default: choose automatically.

*[paper=]*'string', *w=*'dimen', *h=*'dimen'::
        Paper size (see Paper formats above).

*margin=*'dimen', *hmargin=*'dimen', *vmargin=*'dimen', *lmargin=*'dimen', *rmargin=*'dimen', *tmargin=*'dimen', *bmargin=*'dimen'::
        Margins around the tile grid (see Margins above). Defaults to 0.

*pos=*'string'::
        Position of the tile grid on the page (see Positioning above).
        This applies when the *scale* is fixed, or if the aspect ratio of the
        paper (after subtracting margins) does not match the aspect ratio of
        the tile grid. Defaults to *cc*.

*cmark=*'string', *cpen=*'dimen', *clen=*'dimen', *coffset=*'dimen', *ccolor=*'string'::
        Draw cropmarks around each tile. See *crop* for the meaning of arguments.

*tpos=*'string'::
        Position of original pages inside tiles (see Positioning above).
        This applies when different pages have different sizes.
        Defaults to *tl*.

*space=*'dimen', *hspace=*'dimen', *vspace=*'dimen'::
        Insert extra spaces between adjacent tiles in the grid (in both directions,
        horizontally, vertically). This is useful together with *crop*.

paper
~~~~~
Place image on a given paper. Sets a new paper size and translates the image box
according to the given position.

*[paper=]*'string', *w=*'dimen', *h=*'dimen'::
        Paper size (see Paper formats above).

*pos=*'string'::
        Position of the image on the paper (see Positioning above). Default: *cc*.

rotate
~~~~~~
Rotate the page clockwise by multiples of 90 degrees.

*[angle=]*'number'::
        Rotation angle. Must be a multiple of 90 degrees.

scale
~~~~~
Scale the page by a given factor.

*[x=]*'number', *[y=]*'number'::
        Set horizontal and vertical scaling factor. If only one is given,
        it is used in both directions.

scaleto
~~~~~~~
Scale the entire page to a given size.

*[paper=]*'string', *w=*'dimen', *h=*'dimen'::
        Paper size (see Paper formats above).

*pos=*'string'::
        Position of the old paper on the new one (see Positioning above). Default: *cc*.
        This applies if the aspect ratios of both papers do not match.

select
~~~~~~
Selects a subset of pages and optionally applies commands on them.

The select command gets a pipeline. It processes the pipeline stages from the left to the
right. For each stage, it assembles a temporary document containing the selected pages,
applies the stage's commands on it, and appends the resulting document to the output of
the whole select command.

For example, the following command selects pages 1, 10 to 19, and 20 to 29 in reverse order.
The rest of the document is discarded.

        select { 1 10..19 29..20 }

This has the same effect:

        select { 1, 10..19, 29..20 }

This selects two pages and rotates them differently:

        select { 1: rotate(90), 2: rotate(-90) }

The following examples show that the formation of temporary documents can make
a difference sometimes:

        select { 1..10 common, 21..30 common }
        select { 1..10 21..30 common }
        select { 1..10 21..30 } common
        select { 1..10, 21..30 } common

The first command forms two temporary documents and applies common to each of them separately
(therefore pages 1 to 10 will have one common size and pages 21 to 30 another). The remaining
three commands give the same result. The second command forms a single temporary document with 20 pages
and applies common to all of it at once. The third command forms a single temporary document,
which immediately becomes the result of select, to which the final common is applied. And the fourth
command forms two temporary documents, concatenates them to the result of select, and finally applies
common.

slice
~~~~~
Slices the image to several smaller pages. Each page receives a part of the original
image, gluing the parts together produces the original image.

*[paper=]*'string', *w=*'dimen', *h=*'dimen'::
        Paper size of the produced pages (see Paper formats above).

*pos=*'string'::
        Position of the original image on a "canvas" obtained by gluing
        together non-margin parts of the produced pages (see Positioning above).
        Default: *cc*.

*margin=*'dimen', *hmargin=*'dimen', *vmargin=*'dimen', *lmargin=*'dimen', *rmargin=*'dimen', *tmargin=*'dimen', *bmargin=*'dimen'::
        Set margins of the produced pages (see Margins above). Defaults to 0.

*bleed=*'dimen'::
        Let the parts of the image bleed this far outside their boxes.

LICENSE
-------
PaperJam was written by Martin Mares.
It can be distributed and used under the terms of the GNU
General Public License version 2 or any later version.

HISTORY
-------
I conceived the idea of a document processor like PaperJam when struggling with pre-press
formatting in the early 2000's. At that time, the basic ideas behind the language were born,
but everything was deeply rooted in the then standard PostScript world. After some years,
I managed to convince a student of mine Ales Snuparek to implement my ideas as his bachelor's project.
He wrote the program PsPdfTool for transforming both PostScript and PDF documents, which turned
out to be terribly useful.

In the 2010's, limitations of the old design became clear and many PDF documents were using
features not known to PsPdfTool (most prominently object streams). After several years of
pondering, I became fond of the QPDF library and wrote PaperJam as a modern successor of
PsPdfTool.