Bug 481782

Summary:	Okular creates low quality printouts with unselected PDF option "force rasterization"
Product:	[Applications] okular	Reporter:	Tom <mbox.789>
Component:	printing	Assignee:	Okular developers <okular-devel>
Status:	RESOLVED NOT A BUG
Severity:	normal
Priority:	NOR
Version:	21.12.3
Target Milestone:	---
Platform:	Mint (Debian based)
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Printer dialog with PDF Options

Description Tom 2024-02-24 20:06:20 UTC

SUMMARY
Okular seems to prints only in Econo mode.

STEPS TO REPRODUCE
1. Open a pdf document
2. Open print dialog
3. Set "Current Page", "Copies: 1", "Collate", "Long side binding", "Print annotations", "Fit to printable area"
4. Advanced printer properties: "Print Color as Gray: Off", "RGB Color: Default (sRGB)", "Text Neutral Grays: Black Only", "Graphics Neutral Grays: Black Only", "Photo Neutral Grays: 4-Color", "EconoMode: Off", "Media Type: Plain"
5. Click OK to print the page

OBSERVED RESULT
The page is printed in econo mode (gray instead of black, low resolution instead of high resolution)

EXPECTED RESULT
The page should be printed with black text and high resolution as it is done when I print the same page of the same document with same/similar settings with Xreader 4.0.2.

SOFTWARE/OS VERSIONS
Windows: ---
macOS: ---
Linux/KDE Plasma: Linux Mint Mate 21.3
(available in About System)
KDE Plasma Version: ---
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.3

ADDITIONAL INFORMATION
OS: Linux Mint Mate 21.3
Printer: HP Color Laser Jet Pro M252dw
Print system: CUPS 2.4.1

Comment 1 Tom 2024-02-27 02:35:07 UTC

Created attachment 166119 [details]
Printer dialog with PDF Options

I found out in the meantime, that the problem is related to the PDF option "Force rasterization". Per default this option is unselected and as long as it is unselected the quality of the printout is poor, the colors are pale and the resolution is low. However, as soon as "Force rasterization" is selected (ticked) the quality of the printout improves to the expected level with bright colors and a high resolution.

Since I am running okular under Linux Mint Mate 21.3 (so not in a native KDE environment), it seems to be not possible for me to change the default settings of okular, so that when okular is started the next time "Force rasterization" is selected by default.

I also checked an older revision of okular (1.9.3) that has the same default PDF options, but does not create low quality printouts with these settings. So, I assume that the code behind the "Force rasterizatin" option was changed since then.

Comment 2 Tom 2024-03-07 18:39:41 UTC

The root cause of the reported problem was not Okular but either located in cups or HPLIP.