Re: [Gimp-user] What final RGB adjustments before CMYK print?
TenLeftFingers píše v Po 12. 04. 2010 v 17:39 +0200: You're welcome. Party due to this topic, I did an overview of color management involving separate+. You can check it out here: http://www.brankovukelic.com/post/513356271/gimp-color-management-for-dtp I saw that and I have it bookmarked ;) The new site design is great. You should also check with the print shop, if they have experience with colour managed work-flow and what are their expectations of colour encoding. You would know that once you ask for the preferred profile for images in RGB space or for a particular CMYK profile of their printer. If they do not tell you much useful information, you'd better look somewhere else to have your images printed... regards, Milan Knizek knizek (dot) confy (at) volny (dot) cz http://www.milan-knizek.net - About linux and photography (Czech language only) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Color Management Woes
Frank Gore píše v Pá 15. 01. 2010 v 17:12 -0500: But this begs the question, what does Gimp use to determine the embedded color profile? The EXIF data, or something else? Because even if I change that tag from Uncalibrated to Adobe RGB, it still doesn't change how Gimp treats it. Again, you are mixing two different things: embedded profile means that there is an actual binary data inside of JPEG. This can be extracted to a profile.icc if needed. Color Space tag (either standard exif or some proprietary maker note) just says that the image data is in some standard colour space (sRGB, AdobeRGB), but the profile itself is not embedded and the program must supply it on its own. Use of tags instead of embedding profile is an advantage: the image file is a bit smaller. I would assume that GIMP does not care about tags, just looks for any embedded profile. But the developers would have to confirm it. regards, Milan Knizek knizek (dot) confy (at) volny (dot) cz http://www.milan-knizek.net - About linux and photography (Czech language only) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Color Management Woes
Frank Gore píše v Čt 14. 01. 2010 v 21:35 -0500: Sorry, those were links to the version of the pictures as displayed by Picasa, which has the metadata stripped. The direct download links are as follows: I thought your camera would be very unusual to provide JPEGs w/o metadata... Adobe RGB: http://lh6.ggpht.com/_HAZjMzZWrtc/S05qkb7KkYI/BCw/oPJ80XXYH-Y/d/_GOR3359.JPG $ exiftool -a -G -H _GOR3359.JPG | grep Color [File] - Color Components: 3 [EXIF] 0xa001 Color Space : Uncalibrated [MakerNotes]0x0037 Color Space : Adobe RGB $ exiv2 -pa _GOR3359.JPG | grep Color Exif.Pentax.ColorSpace Short 1 Adobe RGB Exif.Pentax.ColorTemperature Short 1 0 Exif.Pentax.ColorInfoUndefined 18 32 131 31 100 31 125 32 156 33 72 32 246 31 51 31 10 0 0 Exif.Photo.ColorSpaceShort 1 Uncalibrated As I stated in my original post, the sRGB image has the EXIF tag Color space set as sRGB. The Adobe RGB picture has that same EXIF tag set as Uncalibrated. That's how it comes right out of the camera. Changing it to Adobe RGB does not change anything. Gimp still doesn't detect the color space properly and still assumes it's sRGB. Here you talk about Exif.ColourSpace. The info above is included in the blob of nonstandard metadata of Pentax... They do in on purpose, since the standard for Exif does not allow AdobeRGB: While the EXIF header in your images does have a field called color space, use of this data is very limited because the only two values allowed in the EXIF color space field are (1) sRGB and (2) unspecified. Anyway, it would be good if graphics programs try to identify also the known maker notes to find out the colour space. Regards, Milan Knizek knizek (dot) confy (at) volny (dot) cz http://www.milan-knizek.net - About linux and photography (Czech language only) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Color Management Woes
Frank Gore píše v St 13. 01. 2010 v 18:20 -0500: In any case, like I mentioned in my original post, I specifically have it set to Ask what to do in the Preferences, and it doesn't ask. I agree with you, it is definitely a bug. GIMP should not assume that JPEG is in sRGB colour space when exif header says Uncalibrated. regards, Milan Knizek knizek (dot) confy (at) volny (dot) cz http://www.milan-knizek.net - About linux and photography (Czech language only) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Color Management Woes
David Gowers píše v Čt 14. 01. 2010 v 18:56 +1030: On Thu, Jan 14, 2010 at 4:18 PM, Frank Gore g...@projectpontiac.com wrote: color profile and ask me about it when I open the file. Isn't that how it's supposed to work? That's what other applications do, for example Digikam/showFoto. In digiKam, the user can pre-set what to do in case of a missing profile. Majority would probably use assign sRGB instead of asking each time. BTW, I just checked the exif information on those JPEGs and both have no EXIF information. So it does look indeed like the profile data is stored in some custom format; there may even be no profile per se stored, just a reference to or description of one. How about the filenames? AdobeRGB image starts with _ (underscore). As far as I can tell, ImageMagick, exiv2 and exiftool do not report any metadata, even not the maker's non-readable ones. Regards, Milan Knizek knizek (dot) confy (at) volny (dot) cz http://www.milan-knizek.net - About linux and photography (Czech language only) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] GIMP vs Photoshop
Norman Silverstone píše v Út 12. 01. 2010 v 20:50 +: The great thing about GIMP is that it is free so you can try it, at no cost to yourself, and see if it will do what you want it to do. But so is Photoshop. 30 days trial :) The difficulty is that whilst GIMP will run on virtually any operating system Photoshop will not. Well, before buying a Mac and trying out, one could give a chance to WINE + Photoshop: http://appdb.winehq.org/objectManager.php?sClass=applicationiId=17 However, the newest versions do not seem to work. Milan Knizek knizek (dot) confy (at) volny (dot) cz http://www.milan-knizek.net - About linux and photography (Czech language only) ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] gimp will strip the exif information in tiff file?
Michael J. Hammel píše v Čt 25. 09. 2008 v 11:57 -0600: To convert back to TIFF you can use ImageMagick's convert tool. According to this discussion: http://www.imagemagick.org/discourse-server/viewtopic.php?f=1t=11600 convert will retain EXIF data. This is true as long as you're simply converting formats and not resizing (such as creating thumbnails). Converting file formats is as simple as convert file.jpg file.tif I am afraid that this might be true only for MS Windows. I tried on linux (ubuntu 8.04 amd64): $ convert orig_with_exif_and_icc.jpg test.tif The test.tif has only the ICC profile embedded, Exif is lost. This might be caused by libtiff library, which is different on the systems. I do not have any TIFF file with Exif, so cannot test what happens on conversions. On linux, support for creating Exif metadata is quite limited - I personally use it only for JPEGs. Also exiftool's man page reads, that it can only read or write, but not create Exif in TIFF images. By the way, if I save these tiff images as another files, will gimp also strip the icc profile? (ps, will gimp strip the icc profile in jpeg?) I looked at using ICC profiles last month in an article I did for Linux Format magazine but I don't think I checked if the profiles were retained when saved. I think I assumed (bad idea) that they were. You'll simply have to try it and see. GIMP does support retaining ICC profiles when you open files that contain them. You're typically queried when you open the file if you want to keep it over convert it to GIMP's built in profile. GIMP retains the ICC profile in TIFF. Best regards, Milan Knizek knizek (dot) confy (at) volny (dot) cz http://www.milan-knizek.net - about linux and photography ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
