HP Officejet Pro X476dw MFP prints in 300dpi

[Schlomo Schapiro]

Running Ubuntu 14.04 running stock hplip 3.14.3

Printer HP Officejet Pro X476dw MFP

hp-check -t output is attached

Problem:

Initially I noticed that printing documents with Hebrew fonts results in low quality with fuzzy lines. After some debugging I was able to trace this down to the fact that by default CUPS converts the print job to a 300dpi PS before giving it to the hp driver:

D [24/Oct/2014:07:22:01 +0200] [Job 261] Printer make and model: HP HP Officejet Pro X576dw MFP
D [24/Oct/2014:07:22:01 +0200] [Job 261] Running command line for pstops: pstops 261 schlomo hebrew-test.pdf 1 'finishings=3 media=iso_a4_210x297mm output-bin=face-down print-color-mode=color print-quality=4 sides=one-sided job-uuid=urn:uuid:c1da9224-d10b-3c2f-6a99-487121b8864c job-originating-host-name=localhost time-at-creation=1414128121 time-at-processing=1414128121 Duplex=None PageSize=A4'
D [24/Oct/2014:07:22:01 +0200] [Job 261] No resolution information found in the PPD file.
D [24/Oct/2014:07:22:01 +0200] [Job 261] Using image rendering resolution 300 dpi
D [24/Oct/2014:07:22:01 +0200] [Job 261] Running command line for gs: gs -q -dNOPAUSE -dBATCH -dSAFER -sDEVICE=ps2write -sOUTPUTFILE=%stdout -dLanguageLevel=3 -r300 -dCompressFonts=false -dNoT3CCITT -dNOINTERPOLATE -c 'save pop' -f /var/spool/cups/tmp/066575456f596

I was able to fix the problem by adding this resolution setting to the PPD:

*DefaultResolution: 600x600dpi

As a result the print job is converted at 600dpi instead of 300dpi which leads to the expected good result:

D [24/Oct/2014:07:22:33 +0200] [Job 262] Printer make and model: HP HP Officejet Pro X576dw MFP
D [24/Oct/2014:07:22:33 +0200] [Job 262] Running command line for pstops: pstops 262 schlomo hebrew-test.pdf 1 'Duplex=None finishings=3 media=iso_a4_210x297mm output-bin=face-down print-color-mode=color print-quality=4 sides=two-sided-long-edge job-uuid=urn:uuid:83e69459-c350-37e5-417d-9ca00f8c6bd9 job-originating-host-name=localhost time-at-creation=1414128153 time-at-processing=1414128153 PageSize=A4'
D [24/Oct/2014:07:22:33 +0200] [Job 262] Using image rendering resolution 600 dpi
D [24/Oct/2014:07:22:33 +0200] [Job 262] Running command line for gs: gs -q -dNOPAUSE -dBATCH -dSAFER -sDEVICE=ps2write -sOUTPUTFILE=%stdout -dLanguageLevel=3 -r600 -dCompressFonts=false -dNoT3CCITT -dNOINTERPOLATE -c 'save pop' -f /var/spool/cups/tmp/0666d544aec68

I think that the PPD is broken because it does not specify a resolution.

It would be nice if the PPD could be fixed.

[Schlomo Schapiro (sschapiro)]

The attached PDF looks very bad when printed in 300dpi and looks good when printed in 600dpi. Somehow this font makes the problem very visible, with latin fonts the difference in quality was less profound.

In 300dpi the lines of the letters look ragged and not crisp.

[Johannes Meixner (jsmeix)]

FYI:
The attached PDF.ppd.gz belongs to
https://answers.launchpad.net/hplip/+question/256131
because it seems one cannot attach files to questions.

[Schlomo Schapiro (sschapiro)]

See http://blog.schlomo.schapiro.org/2015/01/ppd-pimp-your-printer-driver.html, I don't know how to get my fix upstream :-(

[Schlomo Schapiro (sschapiro)]

A year has passed - what do I need to do to get this PPD fix upstream?