GPL Ghostscript 9.06 and PDF/A conformance with modern color profiles

Last update: 31 July 2018

Overview

When using the current color profiles from www.color.org the PDF/A documents generated with GPL Ghostscript produce the error "The value of the key N is 4 but must be 3." in most validators.

Details

This error message is generated because the definition file "PDFA_def.ps" of Ghostscript 9.06 expects that all non grayscale color profiles are using the CMYK color space, which is no longer true for the recommended color profiles from www.color.org, this assumption can be changed by editing the definition file.

To change the assumed color profile of Ghostscript 9.06 simple change the value 4 to 3 in the following line inside the file "PDFA_def.ps" as shown below:

[{icc_PDFA} <</N systemdict /ProcessColorModel get /DeviceGray eq {1} {4} ifelse >> /PUT pdfmark
[{icc_PDFA} <</N systemdict /ProcessColorModel get /DeviceGray eq {1} {3} ifelse >> /PUT pdfmark