Apache OpenOffice (AOO) Bugzilla – Issue 19072
wrong printing resolution if using custom ppd and transparency
Last modified: 2003-10-27 14:54:37 UTC
Hi! I use CUPS with the gimp print drivers using the bundled PPDs with an Epson Stylus Color 640 inkjet printer. This PPD causes problems with OOo: If, for example, I have a frame in a drawing, overlapped by another, transparent frame, OOo renders the whole outer frame into an image before printing. So far that's ok, but it gets the resolution wrong if I use my stc640-PPD. A testcase is attached: The PPD file, the OOo drawing which can be used to reproduce the problem and 4 PS printouts with all combinations of transparency and the cups PPD or generic PPD. The only change I made to drawing before printing is the tiny red frame's transparency, the resolution was set to 720 dpi in all cases. The "transparency with Generic Printer PPD" printout is nearly wrong, although the border lines are much thinner than in the non-transparent versions, but the "transparency with gim print/CUPS PPD" version has a completely wrong, very low resolution. Greetings, Gunter
Created attachment 9011 [details] testcase for this problem, containing an OOo sxd source file, the mentioned PPD and 4 PS "printouts"
I'll have a look.
The wrong resolution read from the provided PPD file is because the file does not conform to the PPD standard; the resolution selected is "720sw" while a resolution option inside a PPD file must be either of form "<a>dpi" or of form "<a>x<b>dpi" according to pages 84-85 of Adobe's "PostScript Printer Description File Format Specification". This unparseable string will get you the default (300dpi), while the generic PPD gets you the selected 720dpi. This leaves the question, why the 720 dpi get you a bad result. I'll have to look into that further.
I tried a little more, but i don't have an Epson Stylus Color 640. I tried with ghostscript and a Xerox Docuprint N24; but this is a 600dpi printer, not 720 dpi. Could you please elaborate on what the quality problem looks like ?
> Could you please elaborate on what the quality problem > looks like ? Uhm, what quality problem, exactly? With the CUPS ppd I got a wrong resolution, you explained the reason yesterday. The only problem I have with transparency and the standard PPD is that the borderline around the boxes (see the testcase) are *much* thinner with transparency enabled, that is, the content prerendered in a graphics. In the example with transparency the border line around the big blue box is so thin it's even not displayed everywhere. Viewing the PS files with plain gs clearly shows this problem. Greetings and thanks a lot for your work, Gunter PS: I understood it correctly that the problem with the CUPS ppd is a plain bug in the PPD file and I should report it to EasySoftware if it's still in the latest CUPS version's PPD, right?
Yes, the cups ppd is buggy in that regard. And you're right, of course, the border is far to thin. I'll forward this to thb who does the transparency rendering..
That's the way it is, when printing to a (relatively low-res) bitmap. The reason that the border is hardly visible in gs is aliasing, BTW. When rendering this bitmap in printer resolution, no difference should be visible on the _printout_.
Closing this issue.