View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000598 | savapage-core | [All Projects] General | public | 2015-10-02 15:17 | 2016-08-01 20:32 |
| Reporter | rijkr | Assigned To | rijkr | ||
| Priority | normal | Severity | feature | Reproducibility | N/A |
| Status | closed | Resolution | fixed | ||
| Product Version | 0.9.9 | ||||
| Target Version | 0.9.11 | Fixed in Version | 0.9.11 | ||
| Summary | 0000598: Add PDF to monochrome conversion before proxy printing | ||||
| Description | IST: Sometimes PDFs get printed as color even if the IPP job instructed monochrome output. SOLL: Add a proxy printer option to convert PDF to monochrome locally before sending it to the printer. This issue was raised when testing the release of Smartschool print jobs from a PaperCut virtual queue. It is observed that in the process of releasing print jobs to a papercut:ipp:// physical queue, and thereby transferring held spool files to physical queues, the original IPP job options are lost and the target print queue defaults are used. So, when the printer queue defaults to "color" the job is printed as color, even when the monochrome option was set by SavaPage. This is a "feature" of PaperCut and can solved by doing client-side grayscale conversion, and configuring physical target queues in CUPS with the Local Raw Printer driver and papercut://socket:x.x.x.x URI. As an alternative we could let PaperCut do the grayscale conversion (but this does not work, and is a pending issue reported to PaperCut as of 2016-05-11). Also see Smartschool issue 0000596 for a workaround by setting specific proxy printers for color/monochrome and simplex/duplex combinations. | ||||
| Tags | No tags attached. | ||||
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Conversion to grayscale PDF is done with command-line Ghostscript. $ gs -sOutputFile=the-graysscale.pdf -sDEVICE=pdfwrite -dNOPAUSE -dBATCH -dPDFUseOldCMS=false \ -sColorConversionStrategy=Gray -sColorConversionStrategyForImages=Gray \ -sProcessColorModel=DeviceGray -dCompatibilityLevel=1.4 the-color.pdf < /dev/null The CMYK result can be inspected per page with this command: $ gs -q -o - -sDEVICE=inkcov the-graysscale.pdf ... 0.00000 0.00000 0.00000 0.32205 CMYK OK 0.00000 0.00000 0.00000 0.24543 CMYK OK 0.00000 0.00000 0.00000 0.24760 CMYK OK 0.00000 0.00000 0.00000 0.23047 CMYK OK If K is the single component GT zero than grayscale is the case. More complex PDFs can show pages results like this: 0.00449 0.00449 0.00449 0.26272 CMYK OK This can be tightened during conversion to pure grayscale again with parameter: -dHaveTransparency=false (at the cost of a substantial performance penalty) But even if "pure" B/W content like this is sent to a socket MFP printer and printed as such, it is observed that a Xerox MFP still counts all printed pages internally as color. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2015-10-02 15:17 | rijkr | New Issue | |
| 2015-10-02 15:17 | rijkr | Status | new => assigned |
| 2015-10-02 15:17 | rijkr | Assigned To | => rijkr |
| 2015-10-05 13:13 | rijkr | Status | assigned => resolved |
| 2015-10-05 13:13 | rijkr | Fixed in Version | => 0.9.10 |
| 2015-10-05 13:13 | rijkr | Resolution | open => fixed |
| 2015-10-07 17:41 | rijkr | Note Added: 0000096 | |
| 2015-11-17 19:49 | rijkr | Relationship added | related to 0000596 |
| 2015-11-17 19:50 | rijkr | Status | resolved => closed |
| 2015-11-17 19:50 | rijkr | Resolution | fixed => won't fix |
| 2015-11-17 19:50 | rijkr | Fixed in Version | 0.9.10 => |
| 2015-11-17 19:50 | rijkr | Target Version | 0.9.10 => |
| 2015-11-17 19:50 | rijkr | Description Updated | View Revisions |
| 2015-11-17 20:30 | rijkr | Relationship added | related to 0000599 |
| 2015-11-17 20:34 | rijkr | Note Edited: 0000096 | View Revisions |
| 2016-05-23 15:53 | rijkr | Status | closed => resolved |
| 2016-05-23 15:53 | rijkr | Resolution | won't fix => fixed |
| 2016-05-23 15:53 | rijkr | Fixed in Version | => 0.9.11 |
| 2016-05-23 15:53 | rijkr | Target Version | => 0.9.11 |
| 2016-05-23 15:53 | rijkr | Description Updated | View Revisions |
| 2016-08-01 20:32 | rijkr | Status | resolved => closed |
