[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
Well, at least Suma Byrappa is the person that has this bug assigned, and Amarnath Chitumalla is listes as "may be notified" on this page. The two should probably know the answer. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
Re: [Bug 1036236] Re: hpcups and hpijs driver use different rasterization
On 02/07/2019, Rüdiger Kupper wrote: > Is the hpcups driver actually being maintained by HP? Or is this a > community driver? I don't know (and I don't even know how to find out!) I also don't know whether the following info has any relevance to your question or not, but: https://github.com/twaugh/hplip/blob/master/check-plugin.py says: # (c) Copyright 2011-2015 HP Development Company, L.P. # Author: Suma Byrappa, Amarnath Chitumalla -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
Is the hpcups driver actually being maintained by HP? Or is this a community driver? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
Re: [Bug 1036236] Re: hpcups and hpijs driver use different rasterization
On 02/07/2019, Matt Whitlock <1036...@bugs.launchpad.net> wrote: > While debugging an unrelated issue with printing to my HP LaserJet 1012, > I switched from the "hpcups" driver to the "hpijs" driver, and I am > **BLOWN AWAY** by the quality of its dithering. After seeing the > difference, I am absolutely appalled at how poorly the "hpcups" driver > dithers grayscales. I had no idea that my cheap little laser printer > could produce such great looking graphics until I discovered the "hpijs" > driver. The "hpcups" driver is garbage by comparison. I totally agree. I love the enforced "upgrade" to something which is completely unusable. Clearly the people at HP are not using HP printers, or this would have been fixed (six) years ago. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
While debugging an unrelated issue with printing to my HP LaserJet 1012, I switched from the "hpcups" driver to the "hpijs" driver, and I am **BLOWN AWAY** by the quality of its dithering. After seeing the difference, I am absolutely appalled at how poorly the "hpcups" driver dithers grayscales. I had no idea that my cheap little laser printer could produce such great looking graphics until I discovered the "hpijs" driver. The "hpcups" driver is garbage by comparison. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
# Hello J T, Hi Rüdiger, # I just resigned and kept using the HPIJS driver, which produces much better # (in terms of visually accurate) output. Exactly the same situation here. # However, Till Kamppeter says that Ubuntu is actively phasing out the HPIJS # driver. This means that the HPCUPS driver needs to be improved/fixed. I have the same opinion too. It is precisely *because* I read that hpijs was being "deprecated" that made me write in and post a comment to your bug report. (The hpijs driver produces good prints with my HP1100 - the hpcups driver, on the other hand, produces images that are completely unacceptable). I have spent an hour reading random HPLIP bug reports and their "resolutions" and as a result, I unfortunately do not hold out much hope that this bug will ever be resolved. While I would love to see the hpcups driver "fixed", I'll continue to use the hpijs driver in the meantime, and if nothing changes before the hpijs driver is "removed", I'll have to go and buy a non-HP printer. Fingers crossed... -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
For the record: Upstream bug is at https://bugs.launchpad.net/hplip/+bug/1036236. But projects are linked. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
Hello J T, thanks for reporting that this is still a problem. I had originally filed this report in 2012, but since it never moved forward I just resigned and kept using the HPIJS driver, which produces much better (in terms of visually accurate) output. However, Till Kamppeter says that Ubuntu is actively phasing out the HPIJS driver. This means that the HPCUPS driver needs to be improved/fixed. This bug is (upstream) assigned to Suma Byrappa, so he/she should be the person to contact. @Suma Byrappa: Can you confirm that hpcups uses different halftoning algorithms (amplitude vs. frequency modulation). Why is this? Why does it mainly concern greyscale prints, not color? How about adding an option of selecting the algorithm in the officially maintained driver (which is hpcups, as I understand)? Thanks for your support! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
J T, you are posting your auto-generated bug data here but do not post a comment telling what is exactly your observation. Note that in HPLIP upstream HPIJS is still contained but not further developed. We also do not explicitly support it any more in Ubuntu, we encourage users to switch to hpcups and do even automatic migration. If you observe any output quality advantage in HPIJS, please report a new bug to HPLIP upstream (https://bugs.launchpad.net/hplip/), so that they can compare and improve the hpcups driver. Nothing of Ubuntu and its packaging is involved here. So I am closing this bug. ** Changed in: hplip (Ubuntu) Status: Incomplete => Won't Fix -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
Hello gf. I am not Rüdiger, the original submitter of this bug, but I am affected by it. Since Rüdiger has not posted to this bug report in over 7 years, I am posting to it to let you know that: 1) It *is* still a problem, 2) I *am* still interested in finding a solution to this bug, and 3) I would like you to *not* close the ticket. Is there a better place for me to report this bug? (HP's FAQ at https://developers.hp.com/hp-linux-imaging-and-printing/faqs suggests reporting it here, but this bug doesn't seem to have had any work done on it since Suma Byrappa (suma-byrappa) became an assignee in December 2013). Thanks. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
ProblemType: Bug ApportVersion: 2.20.10-0ubuntu27 Architecture: amd64 CupsErrorLog: W [20/Jun/2019:09:16:39 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id \'serverLaser.hpijs-Gray..\' already exists W [20/Jun/2019:09:16:39 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id \'serverLaser.hpijs-RGB..\' already exists W [20/Jun/2019:09:17:31 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id \'serverLaser.hpcups-Gray..\' already exists W [20/Jun/2019:09:17:31 +0100] CreateProfile failed: org.freedesktop.ColorManager.AlreadyExists:profile id \'serverLaser.hpcups-RGB..\' already exists CurrentDesktop: ubuntu:GNOME DistroRelease: Ubuntu 19.04 Lpstat: device for serverLaser.hpcups: parallel:/dev/usb/lp0 device for serverLaser.hpijs: parallel:/dev/usb/lp0 MachineType: Hewlett-Packard HP EliteBook 8560p Package: hplip 3.19.1+dfsg0-1 PackageArchitecture: amd64 Papersize: letter PpdFiles: Error: command ['fgrep', '-H', '*NickName', '/etc/cups/ppd/serverLaser.hpcups.ppd', '/etc/cups/ppd/serverLaser.hpijs.ppd'] failed with exit code 2: grep: /etc/cups/ppd/serverLaser.hpcups.ppd: Permission denied grep: /etc/cups/ppd/serverLaser.hpijs.ppd: Permission denied ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.0.0-17-generic root=UUID=e119eace-ded7-4a54-b62d-d08677374c7c ro splash quiet vt.handoff=1 ProcVersionSignature: Ubuntu 5.0.0-17.18-generic 5.0.8 Tags: disco Uname: Linux 5.0.0-17-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True dmi.bios.date: 02/13/2018 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: 68SCF Ver. F.67 dmi.board.name: 1618 dmi.board.vendor: Hewlett-Packard dmi.board.version: KBC Version 97.4E dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.modalias: dmi:bvnHewlett-Packard:bvr68SCFVer.F.67:bd02/13/2018:svnHewlett-Packard:pnHPEliteBook8560p:pvrA0001D02:rvnHewlett-Packard:rn1618:rvrKBCVersion97.4E:cvnHewlett-Packard:ct10:cvr: dmi.product.family: 103C_5336AN dmi.product.name: HP EliteBook 8560p dmi.product.sku: WX787AV dmi.product.version: A0001D02 dmi.sys.vendor: Hewlett-Packard ** Tags added: apport-collected disco -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
Hello Rudiger, Thank you for submitting this bug and reporting a problem with the hplip package. You made this bug report in 2012 and Ubuntu and hplip have been updated since then. Could you confirm that this is no longer a problem and that we can close the ticket? If it is still a problem, are you still interested in finding a solution to this bug? If you are, could you let us know and, in the current version, could you run the following (only once): apport-collect 1036236 and upload the updated logs and and any other logs that are relevant for this particular issue. Thank you again for helping make Ubuntu better. G [Ubuntu Bug Squad volunteer triager] ** Changed in: hplip (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
** Changed in: hplip Assignee: (unassigned) = Suma Byrappa (suma-byrappa) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
Status changed to 'Confirmed' because the bug affects multiple users. ** Changed in: hplip (Ubuntu) Status: New = Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
** Changed in: hplip Status: New = Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
I'd like to add that printing an image (colored, but mostly black) is fine when using the normal mode, but the contrast on the paper is very poor when printing in the normal grayscale mode. Black lines are printed as very light gray lines. I have encountered this on different HP (color) laserjet printers. The problem affects Ubuntu 12.04 (64bit) and Debian squeeze (64bit). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
** Description changed: HPLIP provides two drivers for the Laserjet 1515n: hpcups and hpijs: - hp-color_laserjet_cp1515n-hpijs-pcl3.ppd - hp-color_laserjet_cp1515n-pcl3.ppd The new hpcups shall replace the old hpijs, however, it produces very different rasterization results, resulting in a radically different visual impression. Differences are especially prominent for greyscale prints. Hpcups produces amplitude modulation halftones (dots of different sizes at fixed locations). When resolution is set to Normal, the size of these dots is so large that contours cannot be reproduced with reasonable detail. Heavy aliasing can be easily seen in the circle contours on the Ubuntu Printer test page. Printing photographs in greyscale mode yields badly rasterized images like those known from low- quality newspaper prints (dot pattern is so prominent it dominates image contours). Artifacts are reduced, but still visible at resolution Best. In contrast, hpijs produces frequency modulation halftones with stochastic dithering (small-sized dots placed at varying densities). At resolution Normal, it produces evenly colored areas with reasonably sharp edges. Circle contours on the Ubuntu Printer test page appear continuous. Photographs are reproduced at a a much higher fidelity as with the hpcups driver. Questions: 1. Why do the two drivers use different rasterization? 2. Why is the result of rasterization so bad in the hpcups driver, set at resolution Normal, Greyscale? Note: - Both drivers produce acceptable color prints with much viewer artifacts visible, even at resolution Normal. + Both drivers produce acceptable color prints with much fewer artifacts visible, even at resolution Normal. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: hplip 3.12.2-1ubuntu3.1 ProcVersionSignature: Ubuntu 3.2.0-29.46-generic 3.2.24 Uname: Linux 3.2.0-29-generic i686 ApportVersion: 2.0.1-0ubuntu12 Architecture: i386 CurrentDmesg: [ 63.368304] init: plymouth-stop pre-start process (1700) terminated with status 1 Date: Mon Aug 13 16:38:16 2012 Lpstat: device for Farblaser: hp:/net/HP_Color_LaserJet_CP1515n?zc=NPIE56824 MachineType: exone D156200 Papersize: letter PpdFiles: Farblaser: HP Color LaserJet cp1515n pcl3, hpcups 3.12.2 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-29-generic root=/dev/mapper/lvmvg-Root ro quiet splash vt.handoff=7 SourcePackage: hplip UpgradeStatus: Upgraded to precise on 2012-04-26 (108 days ago) dmi.bios.date: 04/23/2004 dmi.bios.vendor: FUJITSU SIEMENS // Phoenix Technologies Ltd. dmi.bios.version: 4.06 Rev. 1.09.1562 dmi.board.name: D1562 dmi.board.vendor: FUJITSU SIEMENS dmi.board.version: S26361-D1562 dmi.chassis.type: 6 dmi.chassis.vendor: exone dmi.modalias: dmi:bvnFUJITSUSIEMENS//PhoenixTechnologiesLtd.:bvr4.06Rev.1.09.1562:bd04/23/2004:svnexone:pnD156200:pvr:rvnFUJITSUSIEMENS:rnD1562:rvrS26361-D1562:cvnexone:ct6:cvr: dmi.product.name: D156200 dmi.sys.vendor: exone -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
** Description changed: HPLIP provides two drivers for the Laserjet 1515n: hpcups and hpijs: - - hp-color_laserjt_cp1515n-hpijs-pcl3.ppd - - hp-color_laserjt_cp1515n-pcl3.ppd + - hp-color_laserjet_cp1515n-hpijs-pcl3.ppd + - hp-color_laserjet_cp1515n-pcl3.ppd The new hpcups shall replace the old hpijs, however, it produces very different rasterization results, resulting in a radically different visual impression. Differences are especially prominent for greyscale prints. Hpcups produces amplitude modulation halftones (dots of different sizes at fixed locations). When resolution is set to Normal, the size of these dots is so large that contours cannot be reproduced with reasonable detail. Heavy aliasing can be easily seen in the circle contours on the Ubuntu Printer test page. Printing photographs in greyscale mode yields badly rasterized images like those known from low- quality newspaper prints (dot pattern is so prominent it dominates image contours). Artifacts are reduced, bit still visible at resolution Best. In contrast, hpijs produces frequency modulation halftones with stochastic dithering (small-sized dots placed at varying densities). At resolution Normal, it produces evenly colored areas with reasonably sharp edges. Circle contours on the Ubuntu Printer test page appear continuous. Photographs are reproduced at a a much higher fidelity as with the hpcups driver. Questions: 1. Why do the two drivers use different rasterization? 2. Why the result of rasterization so bad in the hpcups driver, set at resolution Normal, Greyscale? Note: Both drivers produce acceptable color prints with much viewer artifacts visible, even at resolution Normal. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: hplip 3.12.2-1ubuntu3.1 ProcVersionSignature: Ubuntu 3.2.0-29.46-generic 3.2.24 Uname: Linux 3.2.0-29-generic i686 ApportVersion: 2.0.1-0ubuntu12 Architecture: i386 CurrentDmesg: [ 63.368304] init: plymouth-stop pre-start process (1700) terminated with status 1 Date: Mon Aug 13 16:38:16 2012 Lpstat: device for Farblaser: hp:/net/HP_Color_LaserJet_CP1515n?zc=NPIE56824 MachineType: exone D156200 Papersize: letter PpdFiles: Farblaser: HP Color LaserJet cp1515n pcl3, hpcups 3.12.2 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-29-generic root=/dev/mapper/lvmvg-Root ro quiet splash vt.handoff=7 SourcePackage: hplip UpgradeStatus: Upgraded to precise on 2012-04-26 (108 days ago) dmi.bios.date: 04/23/2004 dmi.bios.vendor: FUJITSU SIEMENS // Phoenix Technologies Ltd. dmi.bios.version: 4.06 Rev. 1.09.1562 dmi.board.name: D1562 dmi.board.vendor: FUJITSU SIEMENS dmi.board.version: S26361-D1562 dmi.chassis.type: 6 dmi.chassis.vendor: exone dmi.modalias: dmi:bvnFUJITSUSIEMENS//PhoenixTechnologiesLtd.:bvr4.06Rev.1.09.1562:bd04/23/2004:svnexone:pnD156200:pvr:rvnFUJITSUSIEMENS:rnD1562:rvrS26361-D1562:cvnexone:ct6:cvr: dmi.product.name: D156200 dmi.sys.vendor: exone ** Description changed: HPLIP provides two drivers for the Laserjet 1515n: hpcups and hpijs: - hp-color_laserjet_cp1515n-hpijs-pcl3.ppd - hp-color_laserjet_cp1515n-pcl3.ppd The new hpcups shall replace the old hpijs, however, it produces very different rasterization results, resulting in a radically different visual impression. Differences are especially prominent for greyscale prints. Hpcups produces amplitude modulation halftones (dots of different sizes at fixed locations). When resolution is set to Normal, the size of these dots is so large that contours cannot be reproduced with reasonable detail. Heavy aliasing can be easily seen in the circle contours on the Ubuntu Printer test page. Printing photographs in greyscale mode yields badly rasterized images like those known from low- quality newspaper prints (dot pattern is so prominent it dominates image - contours). Artifacts are reduced, bit still visible at resolution + contours). Artifacts are reduced, but still visible at resolution Best. In contrast, hpijs produces frequency modulation halftones with stochastic dithering (small-sized dots placed at varying densities). At resolution Normal, it produces evenly colored areas with reasonably sharp edges. Circle contours on the Ubuntu Printer test page appear continuous. Photographs are reproduced at a a much higher fidelity as with the hpcups driver. Questions: 1. Why do the two drivers use different rasterization? 2. Why the result of rasterization so bad in the hpcups driver, set at resolution Normal, Greyscale? Note: Both drivers produce acceptable color prints with much viewer artifacts visible, even at resolution Normal. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: hplip 3.12.2-1ubuntu3.1 ProcVersionSignature: Ubuntu 3.2.0-29.46-generic 3.2.24 Uname: Linux 3.2.0-29-generic i686 ApportVersion: 2.0.1-0ubuntu12 Architecture: i386
[Bug 1036236] Re: hpcups and hpijs driver use different rasterization
This is a problem of the upstream design of the HPLIP printer drivers by HP, not of the Ubuntu packaging of the drivers. Therefore I am adding an upstream task to make your bug report visible to the developers at HP. Can someone of the HPLIP developers at HP look into this and tell why the two driver flavors (hpcups and hpijs) use so different halftoning algorithms? ** Also affects: hplip Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1036236 Title: hpcups and hpijs driver use different rasterization To manage notifications about this bug go to: https://bugs.launchpad.net/hplip/+bug/1036236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
