THE PDF COLORSPACE ERROR: WHAT IT IS, HOW NOT TO CREATE IT, HOW TO RECOVER FROM IT

by Jeffrey Race

Version 1.11   March 29, 2002

THE SYMPTOM

The most popular format for viewing documents on the web is now PDF, Adobe's Portable Document Format.   It shares the virtue of Adobe's previous technical triumph, PostScript: platform-independent output, within the color and resolution limits of the output device. And since the specifications are published, one can now both view and create PDF files with software from vendors beside Adobe.

But recently many computer users have begun to receive strange error messages when viewing PDF files, such as "Could not find the ColorSpace named 'Cs9' " or "This file contains information not understood by the viewer".

This error occurs when users of Acrobat Reader prior to Version 4 attempt to view files created in Acrobat Distiller 4 or 5 in which the options are incorrectly chosen to maintain compatibility with the installed base of Readers. The problem arose due to an oversight in the coding of Acrobat 4.x.  Manual intervention may be required to prevent the error.

The problem is that the PDF file creators are unaware they are creating offending files because they themselves are immune.

This article explains how to avoid creating offending PDF files (if you are sending files to the public who have a large variety of Reader software) or how to view if you are a victim of such an offending file.


WHO SUFFERS?

Typically the problem occurs when a user of Acrobat Exchange 3.x or Acrobat Reader 3.x or earlier views a file created in Acrobat 4  when the PDF document contains graphical, shading or color elements. Here is an example as seen by the victim.


Example of offending file created with colorspace error as 
  seen by Acrobat 3.0 Reader



CAUSES

After Distiller 4 was released it was discovered that even if you configured it to create a PDF file to the PDF 1.2 specification (i.e., Acrobat 3.x compatibility) but allowed color management features, then the resultant PDF file could contain a colorspace not part of the PDF 1.2 specification.

If on the other hand all colors were in standard RGB, CMYK, and K colorspaces as most typically are and the job options were not set to convert colors to managed colorspaces, then the problem did not occur.

In fact managed colorspaces are not essential to the presentation of text and seldom for graphics so the error is almost always gratuitous.


CREATING INOFFENSIVE PDF FILES WITH ADOBE TOOLS

First and simplest, from a word-processing application, use the Adobe PDFWriter utility which is incapable of generating the colorspace error. However PDFWriter cannot be used in the following cases:

A second choice is to use the more recent Adobe PDFMaker utility, installed in Windows by Acrobat 4 and 5, configured to use Distiller (not PDFWriter):

Third, one can use the standard method of printing to local disk a PostScript file, then running it through Distiller properly configured as above.

Fourth, Photoshop-exported PDF files should not invoke any color management to be fully PDF 1.2-compatible. One must create Photoshop EPS images with option "PostScript Colormanagement" turned off.

Finally, Adobe experts warn that all PDFs exported from recent versions of Illustrator and InDesign may be subject to errors and so require at least Acrobat/Acrobat Reader 4.0.5.


CREATING INOFFENSIVE PDF FILES WITH NON-ADOBE TOOLS

An alternative is to use a non-Adobe tool to create PDFs. For the Windows platform try:

PDF-XChange

BroadGun pdfMachine (Note: pdfMachine does not currently support conversion of documents using PostScript fonts.)

Jaws PDF Creator (Also supports MacOS.)

For OS/2

Ghostscript


HOW TO RECOVER FROM AN OFFENDING FILE

The most important point is to inform the file's creator of his problem so he can recreate a backward-compatible file! He probably doesn't even realize the trouble he is causing his correspondents. You might point him to this help file or send it to him.

Next, you can use a command line utility. For Windows users, a public-spirited author (who requests anonymity) has been kind enough to share the nifty FIXPDF4D.EXE utility with us.

This is a free command-line program. It removes one specific backward-compatibility problem between Acrobat 4 Distiller and Acrobat 3 Reader. The symptom of this problem is the message "Could not find the ColorSpace named 'Cs9' " or Cs6, etc.

The program will either leave your PDF file unchanged, or will do minimal changes to remove this specific problem. If it helps you, great. If your PDF file has any other problem or uses any other Acrobat 4 (PDF 1.3) feature, it won't help that.

Usage: fixpdf4d <input PDF file name> [<output PDF file name>]

   Default output for foo.pdf is foo3.pdf

   [If necessary rename the input file to comply with the 8.3 filenaming convention (no spaces either!).
   Using only 7 characters in the filename will prevent overwriting the input file.]

Input: PDF file with gratuitous iccbased color profile

Output: PDF file without gratuitous iccbased color profile
This utility is available at <www.camblab.com/> .

For OS/2 users, Julian Thomas has implemented the same functionality in a REXX script FIXPDF.CMD, which also accepts filenames with spaces.

   Usage: fixpdf <input PDF file name> [<output PDF file name>]

   Filenames with spaces must be enclosed in double quotes e.g."this stuff.pdf"

   If only an input file name is specified, the input file is saved with .bak extension

This utility is available at <http://jt-mj.net/> ; click on ""OS/2 Links and Tools".

Note that files reporting error "bad CMap Encoding" after fixing as above suffer from a second and different problem (fonts not understood by the viewer, typically using non-Latin glyphs). Such files are not viewable in Acrobat Reader 3; use a later version of Reader, or Ghostscript, to view.


OTHER VIEWING TOOLS TO SOLVE THE COLORSPACE PROBLEM

People using Acrobat Reader 3 experience the colorspace error, so an easy fix is to move to a later Adobe version of Reader. However some computer users cannot do so, while others choose not to. Easier than changing one's viewer is to fix the file as suggested above, but here are some PDF file viewer options.

For OS/2,

   Adobe Acrobat Viewer 1.1 for Java Requires Java 1.1.6 or later

   XPDF for OS/2

  GSview 4.0 (with Ghostview 7.00) for OS/2

   Adobe Reader (Windows versions) with Odin (refer to Tim Sipples' excellent review article in the Resources section)

For Linux a free PDF viewer for the X-Windows system

For DOS Arachne web browser for DOS.

Reader comments and questions are welcome so that this help document may continue to improve.


RESOURCES AND REFERENCES

Recommendations for Creating PDF Files from Word with Acrobat 4.05x

FIXPDF4D.EXE

FIXPDF.CMD

Tim Sipples' viewer review article

To obtain an offending file go to this 3Com site and select "Download datasheet".

For Rob Zacherl's expert explanation of managed colorspace problems in Photoshop go here.


VERSION HISTORY

V 0.95 November 22, 2001: Draft html edition
V 1.00 November 27, 2001: First published version
V 1.01 November 28, 2001: Minor fixes re fix utility input filename; retitle to add PDF
V 1.10 March 24, 2002: Add FIXPDF.CMD for OS/2 and minor textual fixes
V 1.11 March 29, 2002: Minor textual fix



Copyright © 2001, 2002 by Jeffrey Race      Last updated March  29,   2002