Summary: | gs 9 is 10 X slower than gs 8.71 with DEVICE=epswrite | ||
---|---|---|---|
Product: | Ghostscript | Reporter: | William Bader <williambader> |
Component: | PS Writer | Assignee: | Ken Sharp <ken.sharp> |
Status: | RESOLVED FIXED | ||
Severity: | enhancement | CC: | christinedelight.top85, jackie.rosen, michael.vrhel, williambader |
Priority: | P4 | ||
Version: | 9.00 | ||
Hardware: | PC | ||
OS: | Linux | ||
Customer: | Word Size: | --- | |
Attachments: | PDF to show the problem |
Description
William Bader
2011-01-28 03:22:31 UTC
Created attachment 7164 [details]
PDF to show the problem
(In reply to comment #0) > I have some tests with a representative PDF file. The file is black and white, > so I think that the ICC changes shouldn't be an issue. In fact this does look like it *is* something to do with ICC profiles. Although the content of the PDF may appear to be monochrome, there is no monochrome colour space, so the content must be defined in DeviceGray. The ICC code covers *all* colours, even gray. The issue seems to be some form of complexity problem. Not only is the performance degraded, but the output file size is considerably bigger. I haven't yet had a chance to check on why this is so. If you only want PostScript output I would suggest using ps2write instead for now. Thanks for looking at it. >If you only want PostScript output I would suggest using ps2write instead for now. I need EPS because the files are images that I need to place on a page. More specifically, the files are advertisements that I am placing on newspaper pages. Some come as PDF, and I use a batch script that uses gs to convert them to EPS. With gs9, the script does not finish within the deadline to make the pages. >In fact this does look like it *is* something to do with ICC profiles. If it is something that I might have a chance of fixing, can you give me a suggestion of where to look? Is it possible to disable the use of ICC from the command line at run-time or from a configure option during the build? Disabling ICC would give a way to show if it is the problem, and it would be a temporary work-around if it is the problem. William (In reply to comment #3) Although ps2write produces DSC compliant PostScript now, it doesn't yet produce EPS files, so you can't realistically use it. > >In fact this does look like it *is* something to do with ICC profiles. > > If it is something that I might have a chance of fixing, can you give me a > suggestion of where to look? I don't think you'll be able to fix it, and I'm not certain myself what's happening. What I see is that at least one and possibly several images are not remaining as image data. Each sample in the image is being converted to a filled rectangle. Obviously a construct of the form: set colour x y width height rectangle fill Is a *lot* bigger than a simple byte containing the image data. Or even worse a single bit if its truly monochrome (images *can* have 1 bit data, even though they are still specified in DeviceGray space). This takes a lot longer to write out (the current output is at least 5 times larger) and may also take longer to generate internally. > Is it possible to disable the use of ICC from the command line at run-time or > from a configure option during the build? As far as I'm aware, no, neither is possible. I will put it to our colour expert though in case I'm wrong. On the support call, we discussed that we probably should make a ps2write variant that writes EPS conforming output. This bug is already 'enhancement', so we will just leave it open until we get around to a eps2write eps2write now exists. |