README - OpenPrinting CUPS Filters v1.27.5 - 2020-06-05

Looking for compile instructions? Read the file "INSTALL.txt" instead...

INTRODUCTION

CUPS is a standards-based, open source printing system used by
Apple's Mac OS® X and other UNIX®-like operating systems,
especially also Linux. CUPS uses the Internet Printing Protocol
("IPP") and provides System V and Berkeley command-line
interfaces, a web interface, and a C API to manage printers and
print jobs.

This package contains backends, filters, and other software that
was once part of the core CUPS distribution, but during the time
when CUPS was developed at Apple, Apple stopped maintining these
parts as they were not needed by Mac OS.

In addition it contains more filters and software developed
independently of Apple, especially filters for the PDF-centric
printing workflow introduced by OpenPrinting and a daemon to
browse broadcasts of remote CUPS printers and IPP printers to make
them available locally.

Since CUPS 1.6.0 cups-filters is required for using printer
drivers (and also driverless printing) with CUPS under Linux. This
version of cups-filters is only for CUPS 2.2.2 or newer. Please
use the cups-filters 1.x line for older CUPS versions.

For compiling and using this package CUPS (2.2.2 or newer),
libqpdf (10.3.2 or newer), libjpeg, libpng, libtiff, freetype,
fontconfig, liblcms (liblcms2 recommended), libavahi-common,
libavahi-client, libdbus, and glib are needed. It is highly
recommended, especially if non-PDF printers are used, to have at
least one of Ghostscript (preferred), Poppler, or MuPDF.

It also needs gcc (C compiler), automake, autoconf, autopoint, and
libtool. On Debian, Ubuntu, and distributions derived from them
you could also install the "build-essential" package to
auto-install most of these packages.

If Ghostscript is used (via the "gsto..." or the "universal" CUPS
filters), Ghostscript 9.56.0 is required and it has to be built at
least with the "pdfwrite", "ps2write", "cups", "pwgraster",
"appleraster", "pclm", "pclm8", "pdfimage24", "pdfimage8",
"pxlcolor", and "pxlmono" output devices. libcups of CUPS 2.2.2 or
newer is required to buid Ghostscript this way.

The Poppler-based pdftoraster filter needs a C++ compiler which
supports C++11 and Poppler being built with the "./configure"
option "-DENABLE_CPP=ON" for building the C++ support library
libpoppler-cpp. This is the case for most modern Linux
distributions.

If you use MuPDF as PDF renderer make sure to use at least version
1.15, as the older versions have bugs and so some files get not
printed correctly.

For Braille embosser support (see below) you will also need at
least liblouis, ImageMagick, and poppler-utils. Recommended is to
also have liblouisutdml, antiword, docx2txt for more sophisticated
Braille generation representing also the formatting of the input
text. None of these is needed for compiling cups-filters.

CUPS, this package, and Ghostscript contain some rudimentary
printer drivers and especially the filters needed for driverless
printing (currently PWG Raster, Apple Raster, PCLm, and PDF output
formats, for printers supporting IPP Everywhere, AirPrint, Wi-Fi
Direct, and other standards). See
http://www.openprinting.org/drivers/ for a more comprehensive set
of printer drivers for Linux.

See

https://wiki.linuxfoundation.org/openprinting/pdf_as_standard_print_job_format

for information about the PDF-based printing workflow.

Report bugs to

https://github.com/OpenPrinting/cups-filters/issues

or alternatively to

https://bugs.linuxfoundation.org/

Choose "OpenPrinting" as the product and "cups-filters" as the component.

See the "COPYING" files for legal information.

IMAGE PRINTING DEFAULT CHANGED TO "SCALE TO FIT"

Compared to the PostScript-based original CUPS filters there is a
change of defaults: The imagetopdf and imagetoraster filters print
in "scale-to-fit" mode (image is scaled to fill one page but
nothing of the image being cut off) by default.

This is done to support photo printing via AirPrint. The photo
apps on Apple's iOS devices send print jobs as JPEG images and do
not allow to set any options like "scaling" or the page size. With
"scale-to-fit" mode set by default, the iOS photos come out on one
page, as expected.

To get back to the old behavior, supply one of the options
"nofitplot" "filplot=Off", "nofit-to-page", or "fit-to-page=Off".

GHOSTSCRIPT RENDERING OF FILLED PATHS

When Ghostscript is rendering PostScript or PDF files into a
raster format the filled paths are ususally rendered with the
any-part-of-pixel method as it is PostScript standard. On
low-resolution printers, like label printers with 203 dpi,
graphics output can get inaccurate and so for example bar codes do
not work any more. This problem can be solved by letting
Ghostscript use the center-of-pixel method.

This can be done by either supplying the option "-o
center-of-pixel" or "-o CenterOfPixel" on the command line when
printing or by adding a "CenterOfPixel" option to the PPD file and
set it to "true", for example by adding the following lines to the
PPD file of the print queue (usually in /etc/cups/ppd/):

    *OpenUI *CenterOfPixel/Center Of Pixel: PickOne
    *OrderDependency: 20 AnySetup *CenterOfPixel
    *DefaultCenterOfPixel: true
    *CenterOfPixel true/true: ""
    *CenterOfPixel false/false: ""
    *CloseUI: *CenterOfPixel

This option can be used when the print queue uses the gstoraster filter.

POSTSCRIPT PRINTING RENDERER AND RESOLUTION SELECTION

If you use CUPS with this package and a PostScript printer then
the included pdftops filter converts the print job data which is
in PDF format into PostScript. By default, the PostScript is
generated with Ghostscript's "ps2write" output device, which
generates a DSC-conforming PostScript with compressed embedded
fonts and compressed page content. This is resource-saving and
leads to fast wire transfer of print jobs to the printer.

Unfortunately, Ghostscript's PostScript output is not compatible
with some printers due to interpreter bugs in the printer and in
addition, processing (by Ghostscript or by the printer's
interpreter) can get very slow with high printing resolutions when
parts of the incoming PDF file are converted to bitmaps if they
contain graphical structures which are not supported by
PostScript. The bitmap problem especially occurs on input files
with transparency, especially also the ones produced by Cairo
(evince and many other GNOME/GTK applications) which unnecessarily
introduces transparency even if the input PDF has no transparency.

Therefore there are two possibilities to configure pdftops at
runtime:

1. Selection of the renderer: Ghostscript, Poppler, pdftocairo,
Adobe Reader, or MuPDF

Ghostscript has better color management and is generally optimized
more for printing. Poppler produces a PostScript which is
compatible with more buggy built-in PostScript interpreters of
printers and it leads to a somewhat quicker workflow when
graphical structures of the input PDF has to be turned into
bitmaps. Adobe Reader is the PDF renderer from Adobe, the ones who
created PDF and PostScript. pdftocairo is a good choice for the
PDF output of Cairo (for example when printing from evince).  It
is less resource-consuming when rasterizing graphical elements
which cannot be represented in PostScript (like
transparency). Note that pdftocairo only supports PDF input using
DeviceRGB, DeviceGray, RGB or sGray and is not capable of
generating PostScript level 1. So its support is only experimental
and distributions should not choose it as default.

The selection is done by the "pdftops-renderer" option, setting it
to "gs", "pdftops", "pdftocairo", "acroread", "mupdf", or "hybrid":

Per-job:           lpr -o pdftops-renderer=pdftops ...
Per-queue default: lpadmin -p printer -o pdftops-renderer-default=gs
Remove default:    lpadmin -p printer -R pdftops-renderer-default

By default, pdftops uses Ghostscript if this does not get changed
at compile time, for example by the Linux distribution vendor.

Hybrid means Ghostscript for most printers, but Poppler's pdftops
for Brother, Minolta, and Konica Minolta. Printer make and model
information comes from the PPD or via the "make-and-model" option.

2. Limitation of the image rendering resolution

If graphical structures of the incoming PDF file have to be
converted to bitmaps due to limitations of PostScript, the
conversion of the file by pdftops or the rendering by the printer
can get too slow if the bitmap resolution is too high or the
printout quality can degrade if the bitmap resolution is too low.

By default, pdftops tries to find out the actual printing
resolution and sets the resolution for bitmap generation to the
same value. If it cannot find the printing resolution, it uses 300
dpi. It never goes higher than a limit of 1440 dpi. Note that this
default limit can get changed at compile time, for example by the
Linux distribution vendor.

The resolution limit for bitmaps can be changed to a lower or
higher value, or be set to unlimited. This is done by the option
"pdftops-max-image-resolution", setting it to the desired value
(in dpi) or to zero for unlimited. It can be used per-job or as
per-queue default as the "pdftops-renderer" option described
above.

The "pdftops-max-image-resolution" option is ignored when Adobe
Reader is selected as PDF renderer.

POSTSCRIPT PRINTING DEBUG MODE

Sometimes a PostScript printer's interpreter errors, crashes, or
somehow else misbehaves on Ghostscript's output. To find
workarounds (currently we have already workarounds for Brother and
Kyocera) it is much easier to work with uncompressed PostScript.
To get uncompressed PostScript as output, send a job with the
"psdebug" option, with commands like the following:

  lpr -P <printer> -o psdebug <file>
  lp -d <printer> -o psdebug <file>

If you want to send your job out of a desktop application, run

  lpoptions -p <printer> -o psdebug

to make "psdebug" a personal default setting for you.

To extract the PostScript output for a developer to analyse it,
clone your print queue to a one which prints into a file:

  cupsctl FileDevice=yes
  lpadmin -p test -E -v file:/tmp/printout \
  -P /etc/cups/ppd/<name of original queue>.ppd

and print into this queue as described above. The PostScript
output is in /tmp/printout after the job has completed.

This option does not change anything if Poppler's pdftops is used
as renderer.

HELPER DAEMON FOR BROWSING REMOTE CUPS PRINTERS AND IPP NETWORK PRINTERS

From version 1.6.0 on in CUPS the CUPS broadcasting/browsing
facility was dropped, in favour of Bonjour-based broadcasting of
shared printers. This is done as Bonjour broadcasting of shared
printers is a standard, established by the PWG (Printing Working
Group, http://www.pwg.org/), and most other network services
(shared file systems, shared media files/streams, remote desktop
services, ...) are also broadcasted via Bonjour.

Problem is that CUPS only broadcasts its shared printers but does
not browse broadcasts of other CUPS servers to make the shared
remote printers available locally without any configuration
efforts. This is a regression compared to the old CUPS
broadcasting/browsing. The intention of CUPS upstream is that the
application's print dialogs browse the Bonjour broadcasts as an
AirPrint-capable iPhone does, but it will take its time until all
toolkit developers add the needed functionality, and programs
using old toolkits or no toolkits at all, or the command line stay
uncovered.

The solution is cups-browsed, a helper daemon running in parallel
to the CUPS daemon which listens to Bonjour broadcasts of shared
CUPS printers on remote machines in the local network via Avahi,
and can also listen for (and send) CUPS Browsing broadcasts. For
each reported remote printer it creates a local raw queue pointing
to the remote printer so that the printer appears in local print
dialogs and is also available for printing via the command
line. As with the former CUPS broadcasting/browsing with this
queue the driver on the server is used and the local print dialogs
give access to all options of the server-side printer driver.

Note that CUPS broadcasting/browsing is available for legacy
support, to let the local CUPS daemon work seamlessly together
with remote CUPS daemons of version 1.5.x and older which only
support CUPS broadcasting/browsing. In networks with only CUPS
1.6.x servers (or Ubuntu or Fedora/Red Hat servers with CUPS
1.5.x) please use the native Bonjour broadcasting of your servers
and cups-browsed, configured for Bonjour browsing only on the
clients.

Also high availability with redundant print servers and load
balancing is supported. If there is more than one server providing
a shared print queue with the same name, cups-browsed forms a
cluster locally with this name as queue name and printing through
the "implicitclass" backend. Each job triggers cups-browsed to
check which remote queue is suitable for the job, meaning that it
is enabled, accepts jobs, and is not currently printing.  If none
of the remote queues fulfills these criteria, we check again in 5
seconds, until a printer gets free to accommodate the job. When we
search for a free printer, we do not start at the first in the
list, but always on the one after the last one used (as CUPS also
does with classes), so that all printer get used, even if the
frequency of jobs is low. This is also what CUPS formerly did with
implicit classes. Optionally, jobs can be sent immediately into
the remote queue with the lowest number of waiting jobs, so that
no local queue of waiting jobs is built up.

For maximum security cups-browsed uses IPPS (encrypted IPP)
whenever possible.

In addition, cups-browsed is also capable of discovering IPP
network printers (native printers, not CUPS queues) with known
page description languages (PWG Raster, Apple Raster, PDF,
PostScript, PCL XL, PCL 5c/e) in the local network and auto-create
print queues with auto-created PPD files. This functionality is
primarily for mobile devices running CUPS to not need a printer
setup tool nor a collection of printer drivers and PPDs.

cups-browsed can also be started on-demand, for example to save
resources on mobile devices. For this, cups-browsed can be set
into an auto shutdown mode so that it stops automatically when it
has no remote printers to take care of any more, especially if an
on-demand running avahi-daemon stops. Note that CUPS must stay
running for cups-browsed removing its queues and so being able to
shut down. Ideal is if CUPS stays running another 30 seconds after
finishing its last job so that cups-browsed can take down the
queue. For how to set up and control this mode via command line,
configuration directives, or sending signals see the man pages
cups-browsed(8) and cups-browsed.conf(5).

The configuration file for cups-browsed is
/etc/cups/cups-browsed.conf.  This file can include limited forms
of the original CUPS BrowseRemoteProtocols, BrowseLocalProtocols,
BrowsePoll, and BrowseAllow directives. It also can contain the
new CreateIPPPrinterQueues to activate discovering of IPP network
printers and creating PPD-less queues for them.

Note that cups-browsed does not work with remote CUPS servers
specified by a client.conf file. It always connects to the local
CUPS daemon by setting the CUPS_SERVER environment variable and so
overriding client.conf. If your local CUPS daemon uses a
non-standard domain socket as only way of access, you need to
specify it via the DomainSocket directive in
/etc/cups/cups-browsed.conf.

The "make install" process installs init scripts which make the
daemon automatically started during boot. You can also manually
start it with (as root):

/usr/sbin/cups-browsed &

or in debug mode with

/usr/sbin/cups-browsed --debug

Shut it down by sending signal 2 (SIGINT) or 15 (SIGTERM) to
it. The queues which it has created get removed then (except a
queue set as system default, to not loose its system default
state).

On systems using systemd use a
/usr/lib/systemd/system/cups-browsed.service file like this:

    [Unit]
    Description=Make remote CUPS printers available locally
    After=cups.service avahi-daemon.service
    Wants=cups.service avahi-daemon.service

    [Service]
    ExecStart=/usr/sbin/cups-browsed

    [Install]
    WantedBy=multi-user.target

On systems using Upstart use an /etc/init/cups-browsed.conf file like this:

    start on (filesystem
              and (started cups or runlevel [2345]))
    stop on runlevel [016]

    respawn
    respawn limit 3 240

    pre-start script
        [ -x /usr/sbin/cups-browsed ]
    end script

    exec /usr/sbin/cups-browsed

These files are included in the source distribution as
utils/cups-browsed.service and utils/cups-browsed-upstart.conf.

In the examples we start cups-browsed after starting
avahi-daemon. This is not required. If cups-browsed starts first,
then Bonjour/DNS-SD browsing kicks in as soon as avahi-daemon comes
up. cups-browsed is also robust against any shutdown and restart
of avahi-daemon.

Here is some info on how cups-browsed works internally (first concept of a
daemon which does only Bonjour browsing):

- Daemon start
  o Wait for CUPS daemon if it is not running
  o Read out all CUPS queues created by this daemon (in former sessions)
  o Mark them unconfirmed and set timeout 10 sec from now
- Main loop (use avahi_simple_poll_iterate() to do queue list maintenance
             regularly)
  o Event: New printer shows up
    + Queue for printer is already created by this daemon -> Mark list
      entry confirmed, if discovered printer is ipps but existing queue ipp,
  upgrade existing queue by setting URI to ipps. Set status to
  to-be-created and timeout to now-1 sec to make the CUPS queue be
  updated.
    + Queue does not yet exist -> Mark as to-be-created and set
  timeout to now-1 sec.
  o Event: A printer disappears
    + If we have listed a queue for it, mark the entry as disappeared, set
      timeout to now-1 sec
  o On any of the above events and every 2 sec
    + Check through list of our listed queues
      - If queue is unconfirmed and timeout has passed, mark it as
        disappeared, set timeout to now-1 sec
      - If queue is marked disappered and timeout has passed, check whether
    there are still jobs in it, if yes, set timeout to 10 sec from now,
    if no, remove the CUPS queue and the queue entry in our list. If
    removal fails, set timeout to 10 sec.
  - If queue is to-be-created, create it, if succeeded set to
    confirmed, if not, set timeout to 10 sec fron now. printer-is-shared
    must be set to false.
- Daemon shutdown
  o Remove all CUPS queues in our list, as long as they do not have jobs.

Do not overwrite existing queues which are not created by us If
the simple <remote_printer> name is already taken, try to create a
<remote_printer>@<server> name, if this is also taken, ignore the
remote printer. Do not retry, to avoid polling CUPS all the time.

Do not remove queues which are not created by us. We do this by
listing only our queues and remove only listed queues.

Queue names: Use the name of the remote queue. If a queue with the
same name from another server already exists, mark the new queue
as duplicate and when a queue disappears, check whether it has
duplicates and change the URI of the disappeared queue to the URI
of the first duplicate, mark the queue as to-be-created with
timeout now-1 sec (to update the URI of the CUPS queue) and mark
the duplicate disappeared with timeout now-1 sec. In terms of
high availability we replace the old load balancing of the
implicit class by a failover solution. Alternatively (not
implemented), if queue with same name but from other server
appears, create new queue as <original name>@<server name without
.local>. When queue with simple name is removed, replace the first
of the others by one with simple name (mark old queue disappeared
with timeout now-1 sec and create new queue with simple name).

Fill description of the created CUPS queue with the Bonjour
service name (= original description) and location with the server
name without .local.

stderr messages only in debug mode (command line options:
"--debug" or "-d" or "-v").

Queue identified as from this daemon by doing the equivalent of
"lpadmin -p printer -o cups-browsed-default", this generates a
"cups-browsed" attribute in printers.conf with value "true".

CUPS FILTERS FOR PDF AS STANDARD PRINT JOB FORMAT

Here is documentation from the former CUPS add-on tarball with the filters
for the PDF-based printing workflow: imagetopdf, texttopdf,
pdftopdf, and pdftoraster

The original filters are from http://sourceforge.jp/projects/opfc/

NOTE: the texttops and imagetops filters shipping with this package
are simple wrapper scripts for backward compatibility with third-party
PPD files and custom configurations. There are not referred to in the
cupsfilters.convs file and therefore not used by the default
configuration. Direct conversion of text or images to PostScript is
deprecated in the PDF-based printing workflow. So do not use these
filters when creating new PPDs or custom configurations. The parameters
for these filters are the same as for texttopdf and imagetopdf (see
below) as the ...tops filter calls the ....topdf filter plus
Ghostscript's pdf2ps.

IMAGETOPDF

1. INTRODUCTION

This program is "imagetopdf". "imagetopdf" is a CUPS filter which reads a single image file, converts it into a PDF file and outputs it to stdout.

This program accepts the following image file format;

gif, png, jpeg, tiff, photocd, portable-anymap, portable-bitmap, portable-graymap, portable-pixmap, sgi-rgb, sun-raster, xbitmap, xpixmap, xwindowdump

xbitmap, xpixmap and xwindowdump images are converted into png images by the "convert" command. Other kinds of image file format can be supported if the "convert" command support them.

Output PDF file format conforms to PDF version 1.3 specification, and input image is converted and contained in the output PDF file as a binary format non-compression image.

"imagetopdf" may outputs multiple pages if the input image exceeds page printable area.

2. LICENSE

"imagetopdf.c" is under the CUPS license. See the "COPYING" file. For other files, see the copyright notice and license of each file.

3. COMMAND LINE

"imagetopdf" is a CUPS filter, and the command line arguments, environment variables and configuration files are in accordance with the CUPS filter interface.

imagetopdf

"imagetopdf" ignores and .

together with the environment variables "PPD" and "CLASSIFICATION".

When omitting , "pdftopdf" reads a PDF file from stdin. Internally this will write the data to a temporary file, because the PDF format cannot be processed in a streaming fashion.

are delimited by space; boolean type CUPS options can be set by only adding the option key, other types are provided as pairs of key and value, =.

pdftopdf processes the following standard command-line and/or PPD options:

Copies # ppd will only override, when commandline parameter was 1 fitplot / fit-to-page / ipp-attribute-fidelity landscape / orientation-requested PageSize / page-size / MediaSize / media-size page-left / page-right / page-bottom / page-top media-top-margin / media-left-margin / media-right-margin / media-bottom-margin Duplex / JCLDuplex / EFDuplex / JD03Duplex / sides number-up / number-up-layout page-border OutputOrder / OutputBin / DefaultOutputOrder / page-delivery page-label page-set page-ranges MirrorPrint / mirror emit-jcl position Collate / multiple-document-handling / sheet-collate cupsEvenDuplex cupsManualCopies # via ppd

Additional (non-standard) options

1. Booklet printing

booklet=Off/On/Shuffle-Only

"On" also tries to set DuplexTumble (two-sided-short-edge) and forces number-up=2

booklet-signature=(multiple of 4, or default: -1 to use "all pages")

2. Page autorotate

pdftopdf automatically rotates pages to the same orientation, instead of (e.g. fitplot) scaling them down unrotated. This behavier can be controlled by

pdfAutorotate / nopdfAutorotate

Specifically, if a PDF file contains pages with page width greater than page height (a landscape page), such pages are automatically rotated anticlockwise by 90 degrees, unless the PPD file specifies "*LandscapeOrientation: Minus90". In this case, clockwise rotation is used. To turn off the feature on a job-by-job basis use

lp -d <print_queue_name> -o nopdfAutorotate

On a per-queue basis use

-o nopdfAutorotate-default

as an option to lpadmin.

When the 'landscape' or 'orientation-requested=4' (or =5) option of CUPS is given, the pdfAutorotate processing will adjust and accordingly rotate the non-landscape pages are rotated instead.

Note: Some pages might end up 180 degree rotated (instead of 0 degree). Those should probably be rotated manually before binding the pages together.

3. Method of flattening interactive PDF forms and annotations.

Some PDF files (like application forms) contain interactive forms which the user can fill in inside a PDF viewer like evince. The filled in data is not integrated in each page of the PDF file but stored in an extra layer. Due to this the data gets lost when applying manipulations like scaling or N-up to the pages. To prevent the loss of the data pdftopdf flattens the form before doing the manipulations. This means the PDF will be converted into a static PDF file with the data being integral part of the pages.

The same flattening is needed for annotations in PDF files.

By default the actual flattening work is done by QPDF, as QPDF is also doing everything else in pdftopdf. This way no external utilities need to be called and so extra piping between processes and extra PDF interpreter runs are avoided which makes the filtering process faster.

As we did not test the new QPDF-based form-flattening with thousands of PDF files yet and it has not been available to actual users yet it is possible that there are still some bugs. To give users a possibility to work around possible bugs in QPDF's form flattening, we have introduced an option to get back to the old flattening by the external tools pdftocairo or Ghostscript.

The selection of the method is done by the "pdftopdf-form-flattening" option, setting it to "auto", "qpdf", "pdftocairo", "ghostscript", "gs", "internal" or "external":

Per-job: lpr -o pdftopdf-form-flattening=pdftocairo ... Per-queue default: lpadmin -p printer -o pdftopdf-form-flattening-default=gs Remove default: lpadmin -p printer -R pdftopdf-form-flattening-default

By default, pdftopdf uses QPDF if the option is not supplied, also the settings "auto" and "internal" make QPDF being used. "external" auto-selects from the two external utilities, trying pdftocairo at first and on failure Ghostscript. If the selected utility fails, the form stays unflattened and so the filled in data will possibly not get printed.

Native PDF Printer / JCL Support

Note that for most modern native PDF printers JCL is not needed any more as they are controlled via IPP. For these the PPD files get auto-generated by the support of CUPS and cups-filters for driverless IPP printing.

pdftopdf will emit JCL when provided with a PPD file that includes the "*JCLToPDFInterpreter:" keyword.

This enables for hardware copy generation and device collate; e.g. with PJL:

*JCLBegin: "<1B>%-12345X@PJL JOB<0A>" *JCLToPDFInterpreter: "@PJL ENTER LANGUAGE = PDF <0A>" *JCLEnd: "<1B>%-12345X@PJL EOJ <0A><1B>%-12345X"

For each marked option, the prefixed "pdftopdfJCL" keywords can also be used to send raw JCL strings for that option. These keywords also include *pdftopdfJCLBegin and *pdftopdfJCLCopies, This allows the use of the same PPD for PDF- and PS-based workflows, as pdftopdfJCL... will not be read in the PS case.

When the PPD contains the "Copies" keyword, pdftopdf will detect the use of PJL and has special code which adds "@PJL SET COPIES=...", or "@PJL SET QTY=...", respectively.

Other JCL code can be injected via "*JCLOpenUI: ..." ... "*JCLCloseUI: ...".

Special PDF comments

pdftopdf adds comments to the pdf preamble that might esp. be of use to subsequent filters, e.g.

% This file was generated by pdftopdf %%PDFTOPDFNumCopies : 1 %%PDFTOPDFCollate : false

The "NumCopies" and "Collate" values refer to the expected device/hardware copies, i.e. when pdftopdf's soft-copy generation did not handle this options.

Limitations

pdftopdf does not support functions that are not related to printing features, including interactive features and document interchange features. Many of these operators and sections are just ignored. Some of these may be output, but those functions are not assured.

Most notable is the use of AcroForms; their content will not be printed if any non-trivial processing by pdftopdf is involved (e.g. "fitplot"). This only occurs when a file is printed directly, e.g. by "lpr".

Usual PDF viewer applications (xpdf, evince, acroread, ghostscript, ...) will hardcopy the form content into printable pdf operations, when choosing to print such a document.

Known issues

• Borders, esp. in the "number-up=1 fitplot=false"-case might be drawn at incorrect locations.

• JCL documentation is sparse. The imagetopdf or old pdftopdf documentation contains a tad more information.

• Missing AcroForm-content might surprise users printing PDF files directly / from the command-line (see the Limitations section, above).

License

pdftopdf is released under the MIT license.

The required libqpdf is available under version 2.0 of the Apache License, e.g. here: https://github.com/qpdf/qpdf

TEXTTOPDF

This implements a texttopdf filter, and is derived from cups' texttops.

To configure:

• texttopdf uses CUPS_DATADIR/charset/pdf.utf-8 for font configuration (when utf-8 was requested as charset). The font names given there are used as fontconfig selectors; the best matching font, that is both monospaced and in a supported format (TTC, TTF or OTF) will then be used.

• As a special exception, all fontnames that start with a '.' or '/' are considered filenames, and fontconfig is skipped; the name is used directly for loading the font file.

• Implementation note: TrueType Collections (.TTC) are internally handled by appending '/' and the index of the font inside the collection to the filename (e.g. to use the second font of uming.ttc, the filename uming.ttc/1 must be given to the fontembed-library). By appending the index-field returned from fontconfig, this is completely transparent to the user (but currently not widely tested).

• You may look at the two examples: pdf.utf-8.simple and pdf.utf-8.heavy.

To use:

The filter is called just like any other cups filter. Have a look at test.sh for example.

Known Issues

• Text extraction does not work (at least for pdftotext from xpdf) for the resulting pdfs.

• OTF(CFF) embedding currently does not subset the fonts.

• Text wrapping in pretty-printing mode does not respect double-wide characters (CJK), and thus produce wrong results (wrap too late) for lines where they occur. The fix is not trivial, since all the pretty-printing processing is done without knowledge of / prior to the font configuration (which is where single or double width code-ranges are specified).

• The hebrew example in test5.pdf shows one of our limitations: Compose glyphs are not composed with the primary glyph but printed as separate glyphs.

Further Infos

Font embedding is handled by libfontembed in the filter/fontembed subdirectory.

Please report all bugs to

https://github.com/OpenPrinting/cups-filters/issues

or to

https://bugs.linuxfoundation.org/

(product "OpenPrinting", component "cups-filters").

PDFTORASTER

1. INTRODUCTION

"pdftoraster" is a filter for CUPS. It reads PDF files, convert it and output CUPS raster.

"pdftoraster" does not support functions that are not related to printing features, including interactive features and document interchange features. Many of these operators and sections are just ignored. Some of these may be output, but those functions are not assured. Encryption feature is not supported.

2. LICENSE

Almost all source files are under MIT like license. However, "pdftoraster" links some "poppler" libraries, and these files are under GNU public license. See copyright notice of each file for details.

3. COMMAND LINE

"pdftoraster" is a CUPS filter, and the command line arguments, environment variables and configuration files are in accordance with the CUPS filter interface.

pdftoraster

"pdftoraster" ignores and .