Implementing PDF/X-4

PDF/X-4
from Creation to
Output
Peter Kleinheider
Co-Chair of GWG Specifications Subcommittee
inpetto premedia consulting, owner
peter@inpetto.cc

Agenda
•PDF/X-4 workflow
•PDF/X-4 features
•PDF/X-4 creation
•PDF/X-4 processing
•PDF/X-4 output
•Transparency - a closer look

native PDF/X-4 Workflow
Image
and
artwork
Layout
PDF/X-4
Output
/X
Export
GWG2011 Spec
Proof of
Preflight
Trapping
Export to PDF (via PS and pdfmark)
Impose
Output

PDF/X-4 – lets start using it
•… the Standard has ripened
−PDF/X-4:2010 - technical update last September
−no ambiguity
•… the Workflows have ripened
−at Drupa 2008, Adobe announced Print Engine 2
(APPE)
−EFI announced use of APPE with IPEX 2010
−major (soft-)proofing software is based on native
PDF rendering
−Harlequin Version 8 supports PDF1.6
•… the applications are ripe

Transparency -the major
force to move to PDF/X-4
•live transparency is supported since
PDF 1.4

classical usage
Drop-shadows
„ W e r n o c h n a c h S o m m e r - L e k t ü r e s u c h t : H i e r i s t s i e ! “
Brigitte
„... gehört zum besten
elegischen Ton der
Ge genwart.“ FAZ
„Eine ungeheuer
fesselnde und sinnliche
Erzählung von
besonderer sprachlicher
Schönheit. Eine echte
Entdeckung.“
Amelie Fried in der ZDF-
Sendung „Die Vorleser“
„So eindrucksvoll ist das
Ende der Kindheit lange
nicht mehr beschrieben
worden.“
Spiegel Online
224 Seiten, gebunden, mit Schutzumschlag und Lesebändchen
19,90 E [D], ISBN 978-3-86648-101-5, www.mare.de

classical usage
image clipping

extensive use of
transparency

why keep transparency in
PDF?
−ability to search is preserved
−higher quality
• transparency effects are directly rendered to high-res raster image
−no object clipping
• no unnecessary trapping where not needed
−no image clipping
−ability to edit is preserved
−no unnecessary object conversion (Text-2-Outline)

why keep transparency in
PDF?
−allows color managed PDFs
• objects can keep their original color space since the file is not
flattened to the blending color space
−keep spot colors definitions till the very end
−no flattening errors
−no viewing issues
• no antialias effects when viewing (thin white lines)
• Acrobat (Reader) does not rely on overprint simulation
−faster export
−smaller files

further PDF/X-4 aspects
•support for optional content (layers)

Optional Content
áka Layers
−Variant 1: OCMD - Optional Content Membership
Configuration
−Variant 2: OCCD - Optional Content Configuration
Dictionary
−Acrobat support OCMD
−Acrobat 9 supports OCCDs when PDF is X-4
−Acrobat X does not support OCCD
−support to create such optional content is currently
limited
• need of specialized software
• NEW: InDesign CS 5.5 also supports OCMD export

OCMDs (in Acrobat X)

OCCDs (in Acrobat 9)

OCCDs (in Acrobat X)

further PDF/X-4 aspects
•modern compression methods
−JPEG 2000 - for halftone image date
−JBIG2 - for monochrome image data
•both result in smaller files
•same or higher quality (JPEG 2000)

Filesize/Quality comparison
•Original TIFF: 4,6MB
•TIFF/ZIP: 2,6MB
•JPEG/max. Q: 2,3MB
•JPEG 2000/lossless: 2,2MB
•JPEG/low Q: 1,9MB
•JPEG 2000/max. Q: 1,7MB
•JPEG 2000/low Q: 1,7MB

further PDF/X-4 aspects
•OpenType Fonts
−most OpenType Fonts get converted to other font
file formats when generating PDF
•ICC v4 Profiles
−not allowed in GWG2011 spec until we have further
feedback that there is a real benefit and the
technology has proven to work
•16-Bit images
−more details when converting to CMYK

PDF/X-4 and color
•all icc based color definitions are allowed
•GWG2011 spec restricts the usage
−CMYK/Spot only variant
−ICC/CMYK/Spot variant
•

PDF/
X-1a
PDF/X-4
CMYK
PDF/X-4
RGB (ICC)
PDF/X-4
Full
Color images
• DeviceCMYK
• DeviceGray
• DeviceRGB
• ICC based CMYK
• ICC based Gray
• ICC based RGB / Lab
OK
OK
Error
Error
Error
Error
OK
OK
Error
Error
Error
Error
OK
OK
Error
Warning
Error
OK
OK
OK
Error
OK
OK
OK
Color text + vector
• DeviceCMYK
• DeviceGray
• DeviceRGB
• ICC based CMYK
• ICC based Gray
• ICC based RGB / Lab
OK
OK
Error
Error
Error
Error
OK
OK
Error
Error
Error
Error
OK
OK
Error
Error
Error
Warning
OK
OK
Error
OK
OK
OK
Transparency blend
color space
NA DeviceCMYK /
OutputIntent
DeviceCMYK /
OutputIntent
Anything
Other features
• Transparency
• Layers (OCCD)
• 16-bit images
• JPEG2000 compression
Error
Error
Error
Error
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK

PDF/X-4 creation

PDF/X-1a creation
Image
and
artwork
Layout
PDF/X-1a
/X
Export
GWG 1v4
Check

PDF/X-4 (CMYK) creation
Image
and
artwork
Layout
PDF/X-4
/X
Export
GWG2011
Check

PDF/X-4 (ICC) creation
Image
and
artwork
Layout
PDF/X-4
/X
Export
GWG2011 ICC
Check

PDF/X-4 processing
•trapping
•device link conversion
•layout using PDF/X-4 file

PDF/X-4 and transparencies
•final color in output is not necessary the
objects color in the PDF
−Example: 50% gray in on plate can be defined as
100% Black having 50% transparency or a 50%
transparent white object over a Black object
•color conversion to same visual
appearance might lead to different visual
appearance when using transparency
−typical usage:”ink saving”
•a PDF/X-4 file represents a “digital
master” which should not be modified

Trapping
•trapping is only possible in output color
space (CMYK/Spot)
•object oriented trapping works only partly
−between CMYK/Spot colored objects
−latest updates introduced “trapping exceptions”
−object oriented trapping solutions do not trap
objects with applied transparency or color space
not CMYK/Spot (mostly)
•trapping is being moved to Renderer
−same technology as PostScript InRip Trapping
based on color density

•same issue with overprinting objects
DeviceLink Conversion
•DL conversion is only possible on “known
color” definitions
•Version 1: Colorserver takes into account
transparency
−sometimes involves flattening
−still unsolved issue
•Version 2: support for DL profiles in PDF
renderer on final rendered image
−APPE SDK allows own developments
−APPE Plug/in possible?

“reuse of” PDF/X-4 in layout
applications
•“limited” PDF/X support in layout
applications for placed content
−OutputIntent is (mostly) ignored
−OutputIntent must be same as Document color
space
•PDF/X-1a output causes the content of
the placed PDF being flattened
−varying quality depending of used layout product
•if reused for other printing condition,
better prepare new or use DeviceLink
profiles

PDF/X-4 output
•use of native PDF renderer
•advantage of PDF renderer

native PDF/X-4 Workflow
PDF/X-4
Desktop Viewing
/X
Soft Proof
X-4 requires native PDF
rendering at every
stage
Hardcopy Proof
Output

Why native PDF rendering?
−directly from PDF to image model of output device
• no flattening
• no unnecessary color conversion
−possibility to use PDF functions that are not
possible in other formats
−no intermediate format
• no loss of information
• no transformation to other object model
−high quality transparency rendering
−no flattening of transparency at any stage
−possibility of color mapping at the very latest stage

What if output device does
not handle PDF/X-4?
•Best: recreated PDF as PDF/X-1a
•Possibility 1: convert color and flatten
•Possibility 2: render to image
−works best for low res output devices such as
digital printing machines working with 600dpi

simplified transparency
blending in PDF/X-4
Document OutputIntent: ISOcoatedv2
Page blending CS: None/DeviceCMYK
non-isolated group blending CS: None/DeviceCMYK
Image: ECI-RGB v2
Shadow (image): DeviceCMYK 100K
alpha: 0.75
mode: Multiply
Info: a page group is usually treated as isolated transparency group
1.page group blending color space is inherited from Output Intent if None or DeviceCMYK ISOcoatedv2
2.blending color space of none isolated transparency group is inherited from embedding isolated
transparency group or from page group (no matter if defined or not)
ISOcoatedv2
3.objects within the transparency group are converted to this color space
ISOcoatedv2
4.transparency mode is “applied” on objects
5.resulting object is converted to page group color space
ISOcoatedv2
ISOcoatedv2
6.resulting object is converted to Output Intent

simplified transparency
blending in PDF/X-4
Document OutputIntent: ISOcoatedv2
Page blending CS: None/DeviceCMYK
non-isolated group blending CS: ECI-RGB v2
Image: ECI-RGB v2
Shadow (image): DeviceCMYK 100K
alpha: 0.75
mode: Multiply
1.page group blending color space is inherited from Output Intent if None or DeviceCMYK ISOcoatedv2
2.blending color space of none isolated transparency group is inherited from embedding isolated
transparency group or from page group (no matter if defined or not)
ISOcoatedv2
3.objects within the transparency group are converted to this color space
ISOcoatedv2
4.transparency mode is “applied” on objects
5.resulting object is converted to page group color space
ISOcoatedv2
ISOcoatedv2
6.resulting object is converted to Output Intent

simplified transparency
blending in PDF/X-4
Document OutputIntent: ISOcoatedv2
Page blending CS: None/DeviceCMYK
isolated group blending CS: ECI-RGB v2
Image: ECI-RGB v2
Shadow (image): DeviceCMYK 100K
alpha: 0.75
mode: Multiply
1.page group blending color space is inherited from Output Intent if None or DeviceCMYK ISOcoatedv2
2.blending color space of none isolated transparency group is inherited from embedding isolated
transparency group or from page group (no matter if defined or not)
ECI-RGB v2
3.objects within the transparency group are converted to this color space
ECI-RGB v2
4.transparency mode is “applied” on objects
Black is now RGB!
5.resulting object is converted to page group color space
ISOcoatedv2
ISOcoatedv2
6.resulting object is converted to Output Intent

simplified transparency
blending in PDF/X-4
Document OutputIntent: ISOcoatedv2
Page blending CS: ECI-RGB v2
non-isolated group blending CS: None/DeviceCMYK
Image: ECI-RGB v2
Shadow (image): DeviceCMYK 100K
alpha: 0.75
mode: Multiply
1.page group blending color space is inherited from Output Intent if None or DeviceCMYK ECI-RGB v2
2.blending color space of none isolated transparency group is inherited from embedding isolated
transparency group or from page group (no matter if defined or not)
ECI-RGB v2
3.objects within the transparency group are converted to this color space
ECI-RGB v2
4.transparency mode is “applied” on objects
Black is now RGB!
5.resulting object is converted to page group color space
ECI-RGB v2
ISOcoatedv2
6.resulting object is converted to Output Intent

what does this mean for the
GWG2011 ICC specification
•if there is no other color definition used
on a page other than CMYK/Spot, there
must not be a blending color space other
than None or DeviceCYMK
•up for discussion:
−if there is no other color definition used inside an
isolated transparency group other than CMYK/Spot,
there must not be a blending color space other
than None or DeviceCYMK

Thank you
Peter Kleinheider
peter@inpetto.cc
skype: gironimus
mobil: +43.664.2600099