| | <<<Back 1 day (to 2019/11/03) | Fwd 1 day (to 2019/11/05) >>> | 20191104 |
| kens | scrambles the equivalent of -sColorConversionStrategy in 9.50 is -sColorConversionStrategy. You don't need to set ProcessColorModel with pdfwrite, haven't for ages, setting the colour conversion does it. | 08:51.14 |
| | I woulnd't use -dNOCACHE as that turns fonts into outlines, if you want to do that, there's a pdfwrite switch to do it. | 08:52.12 |
| | Other than that, ,I see no problem with the command line, but you haven't explained your problem at all. | 08:52.35 |
| | If you tihkn there is a problem it might be easiest to open a bug report. | 08:52.45 |
| scramblez | Hi All, our printers ask for a 'Fogra39 (ISO 12647-2:2004), do I need to define an ICC Profile in PDFX_def.ps, or change the default entry (ISO Coated sb.icc)? | 16:27.58 |
| kens | scramblez: sounds to me liek your pritner's do not knwo what they are doing | 17:01.17 |
| | Ask tehm what they mean by that. | 17:01.31 |
| | Or just send them a CMYK PDF file and tell them that's what it is | 17:01.51 |
| | Unless you have a fully colour managed workflow that demand is meaningless | 17:02.07 |
| | If you wan the OutpuICCProfile to be set to that, then you need to set -sOutputICCProfile= and supply a FOGRA ICC profile in there, IIRC | 17:03.03 |
| | You always need to change the default entry in PDFX_def.ps, that file is just a template, it shows you waht to do but it is not useful without modification | 17:03.42 |
| scramblez | kens: Thanks! They also ask for PDF/X-1a:2001 ... | 17:17.03 |
| | If I set -dPDFX can I leave the PDFX_def.ps template as is? | 17:18.01 |
| chrisl | scramblez: You probably read through this: https://ghostscript.com/doc/9.50/VectorDevices.htm#PDFX | 17:20.26 |
| scramblez | chrisl: yes, I did read it, but with no background in printing this has been a steep knowledge curve to climb. ;-) | 17:21.16 |
| chrisl | scramblez: Well, the first thing is that the ICC profile(s) are intimately tied to how the content is created, you can't just retro-fit an ICC profile and get good quality | 17:22.35 |
| scramblez | chrisl: I see ... I do have a default_cmyk.icc, in //Resources - couldn't I point to that? | 17:26.17 |
| chrisl | scramblez: Unless your content was created to match that profile, then what's the point? | 17:27.04 |
| scramblez | Well, the content was created in Inkscape, with Fogra27 (I think), but Inkscape saves the PDF with RGB. | 17:28.34 |
| | So, I understood I should run gs to convert it to CMYK. | 17:29.00 |
| chrisl | Such color conversions come with a high risk of quality loss | 17:29.48 |
| scramblez | When I run gs without -dPDFX it converts all images into CMYK. With -dPDFX it creates a much larger PDF with all images combined into a single CMYK image. | 17:30.09 |
| chrisl | That probably means there is transparency in the file | 17:30.36 |
| | Likely, inkscape is using cairo to export the PDF | 17:31.37 |
| scramblez | chrisl: Yes, I understand. There is transparency in the file. Last time we had something printed in this fashion there was a close enough match between the on-screen poster and the hard copy. I guess I could run it through our printer (and waste a tonne of ink!) :) | 17:32.26 |
| chrisl | PDF consumers render the transparency to a "flat" image - the printed copy should match the screen (almost) entirely | 17:33.38 |
| | I don't know for sure, but I suspect PDF-X/3 doesn't allow transparency | 17:34.38 |
| scramblez | chrisl: so that I understand, why the PDF created without -dPDFX had each image saved separately? Is it because without transparency it bitmaps the whole lot into a single flat image? | 17:35.12 |
| | Sorry, meant to write: is it because with -dPDFX it bitmaps the whole lot into a single flat image? | 17:35.47 |
| chrisl | Yes. If you convert into a format with a different or more limited imaging model, the only option is to render to an image | 17:36.35 |
| | So, the same will happen if you convert a PDF with transparency Postscript | 17:37.17 |
| | Or a PDF with transparency into a PDF 1.3 file | 17:37.33 |
| scramblez | chrisl: thanks again. I think I'll send it to them without -dPDFX and see what they make of it. If they can't use it I expect they will complain about its format. | 17:37.49 |
| chrisl | scramblez: Does your inkscape document intentionally use transparency, or is it being added by cairo (because it always does)? | 17:38.48 |
| | scramblez: BTW, kens (and myself) are in the UK, so the best time to catch him is UK office hours - and he knows the most about this stuff | 17:41.54 |
| scramblez | chrisl: The user imported a png image in the poster which had transparency. So I guess it is not cairo doing its own thing. | 17:42.28 |
| | I'll see where we get with this tonight and no doubt I'll be pinging you tomorrow morn. THanks again for your help. | 17:43.01 |
| chrisl | scramblez: Hmm, you can't embed a PNG directly in PDF, so it'll very much depend on what inkscape does with that case. I don't really know, I'm afraid | 17:43.55 |
| scramblez | I find the whole image creation field stupefying and my knowledge is lacking - so I have a lot of catch up to do. | 17:47.10 |
| chrisl | scramblez: It's very much a case a of "standards are great, we should have loads of them!". | 17:49.33 |
| scramblez | chrisl: plus different tools for different jobs, not all compatible with each other. | 17:50.13 |
| chrisl | scramblez: Well, the other option is to pay a load of money to one vendor for an end-to-end solution - expensive, and locks you into that vendor | 17:51.13 |
| scramblez | I'd rather avoid this, especially as this particular job is for a local non-profit choir trying to raise money for local charities. I try to help them as best as I can. | 17:52.58 |
| | chrisl: Is there some link explaining a complete workflow using opensource applications, like gimp, inkscape, scribus & gs to prepare submissions to commercial printers? I would find something like this rather useful. | 18:03.41 |
| chrisl | I'm not really aware of any, but it's not really my/our area | 18:04.46 |
| scramblez | OK, no probs. THanks again for your help. | 18:05.15 |
| manf5 | hi. I was wondering where the best place would be to report a security vulnerability in ghostscript (specifically, -dSAFER escape in 9.27 and also 9.50 with -dOLDSAFER) | 23:06.18 |
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