** 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
