On Mon, Jan 21, 2013 at 3:44 PM, Pascal Obry <[email protected]> wrote: > > Not 100% related to darktable... > > Any experience with printing on an Epson 3880? Which driver? Using > profile during export?
I've recently acquired an Epson R3000, which seems to work well with gutenprint. That said gutenprint has a lot of print modes. And I'm still figuring out the best way to profile the printer. That said, for any printer, particular with non-vendor drivers, it's highly recommended to (custom) profile them. Do mind, that printer/paper vendor icc profiles are unlikely to work with gutenprint. You really need to make custom profiles using a spectrophotometer (or service that does this for you by sending in a print). > On Windows with Lightroom I was: > > - disabling profile on the printer > - using the printer/paper ICC while printing > > On Linux with Darktable, would something like this work: > > - disabling profile on the printer > - using the printer/paper ICC while exporting > - print with Gimp or image viewer, or? Darktable has no print mode indeed. That said, the state of color management on Linux is slowly advancing. Via GNOME Color Manager / colord, cups can actually do rudimentary print color management (independent of the print driver backend). By default this is just passthrough though. Currently I'm not using this, mainly because I don't fully understand what's happening, and I'm not sure how it deals with non-sRGB data. Please don't think that this means there is anything wrong per-se. I just want to understand what happens exactly before I can start recommending this :) My current print workflow is like this: Export an image from darktable to a 16bit TIFF file (AdobeRGB with perceptual rendering intent). # tificc -v -o printer.icc -t 0 darktable_export.tiff raw_print.tiff As you might note I'm _not_ embedding the the printer profile into the raw_print.tiff as I want to send that RGB data straight to my printer (without any further color management (as the image has already been managed :))). Finally I typically load raw_print.tiff into EOG (Eye of GNOME) and print from there, it's the simplest application that has a nice print dialog that allows me to keep a white border around my prints. With regard to rendering intent, some caution is required, I'm using a perceptual rendering intent (with my own custom generated profiles), but this depends on my input file being the same source colorspace (AdobeRGB) as the profile was generated for. Only the relative colorimetric rendering intent should work properly regardless of source colorspace. Both the perceptual rendering intent and saturation rendering intent are calculated specifically from a particular source colorspace to a printer's native device colorspace, this is static because print profiles are almost always LUTs (lookup tables), so the source colorspace is defined at profile generation time. While taking a look at a lot of the profiles from paper vendors, they typically specify as being calculated against AdobeRGB. This is however not specified in the profiles metadata, so if you're transforming an sRGB file with a print profile which was generated for AdobeRGB with either a perceptual or saturation rendering intent, the transform will be off and you'll receive no warning whatsoever (well except for a bad print :)). Regards, Pascal de Bruijn ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122412 _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
