Re: [Gimp-developer] babl roadmap: How do you know which images are sRGB images?
On 10/13/2014 06:36 PM, Elle Stone wrote: How do you plan to tell when an image is an sRGB image and when it's not an sRGB image? The roadmap specifies 24 different formats for sRGB images and 24 additional formats for non-sRGB images. Presumably the 24 additional formats for non-sRGB images allow GEGL to request, as needed, a conversion of the RGB data from being encoded using sRGB primaries to being encoded using User_RGB primaries and vice versa. Given the 24 additional formats for non-sRGB images, it seems pretty important to be able to detect when the user opens an sRGB image and when the user opens an image that's in some other RGB working space. So again, upon opening an image, how do you plan to detect whether the image is an sRGB image or not? Will you compare MD5 checksums? Will you consult the profile descriptions? Will you examine the profile colorants and TRCs? If you don't understand the context of the question, see the following article: Will the Real sRGB Profile Please Stand Up? (http://ninedegreesbelow.com/photography/srgb-profile-comparison.html) It should be noted that the article doesn't list *all* sRGB profile variants (new ones are being made every day). In particular, the article doesn't list sRGB profile variants distributed with Canon, Nikon, etc proprietary software. With respect, Elle Stone -- http://ninedegreesbelow.com Color management and free/libre photography ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
On 10/14/2014 06:54 AM, Øyvind Kolås wrote: So now all chromaticity-dependent editing operations will require a brand new special specifying, unless the image is already an sRGB image. If you didn't intend to convert all images to unbounded sRGB for editing, there wouldn't be any reason to special specify roughly half of all the editing operations that you offer through the GIMP UI. Just like in an ICC based workflow images are converted to unbounded XYZ for editing? (they are not) My apologies, I don't have a clue what you mean by what you just said. But no, XYZ isn't a good color space for image editing, if that is what you are asking. The PCS used by a CMS is an implementation detail; where choices might have been XYZ, linear sRGB or some other linear RGB; of the preceding linear sRGB has nicer properties than any of the others. The above sentence confuses concepts: The babl architecture might require that images to be converted to and from unbounded linear gamma sRGB. That doesn't mean babl is a CMS. And it doesn't mean unbounded linear gamma sRGB has been turned into a PCS. To convert images to and from unbounded linear gamma sRGB, you MUST pass through XYZ. XYZ is the PCS. Let's cut to the chase: Are you planning on converting non-sRGB images to unbounded linear gamma sRGB? Yes or no? If yes, are you intending that at least some editing will be done on the image while it's encoded using sRGB primaries? Yes or no? With respect, Elle Stone ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
On Tue, Oct 14, 2014 at 1:34 PM, Elle Stone ellest...@ninedegreesbelow.com wrote: The above sentence confuses concepts: The babl architecture might require that images to be converted to and from unbounded linear gamma sRGB. That doesn't mean babl is a CMS. And it doesn't mean unbounded linear gamma sRGB has been turned into a PCS. Babls role in the GEGL and thus GIMP architecture is to be the internal CMS; this remains unchanged since babl was split out of a non-linear video editor/compositing system. To convert images to and from unbounded linear gamma sRGB, you MUST pass through XYZ. XYZ is the PCS. I remind you that linear RGB spaces are a single matrix multiplication away from other linear RGB spaces and XYZ. Let's cut to the chase: Are you planning on converting non-sRGB images to unbounded linear gamma sRGB? Yes or no? Foo or bar? Do you have any idea what implementation detail means? /pippin ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
On 10/14/2014 07:52 AM, Øyvind Kolås wrote: On Tue, Oct 14, 2014 at 1:34 PM, Elle Stone ellest...@ninedegreesbelow.com wrote: To convert images to and from unbounded linear gamma sRGB, you MUST pass through XYZ. XYZ is the PCS. I remind you that linear RGB spaces are a single matrix multiplication away from other linear RGB spaces and XYZ. Matrix conversions between RGB working spaces can be concantenated. That concantenation goes through XYZ. It almost sounds like you want to obscure this fundamental distinction between XYZ and unbounded linear gamma sRGB. Let's cut to the chase: Are you planning on converting non-sRGB images to unbounded linear gamma sRGB? Yes or no? Foo or bar? Do you have any idea what implementation detail means? I do know what implementation detail means. You didn't the question, so I'll try again: Are you planning on converting non-sRGB images to unbounded linear gamma sRGB? Yes or no? If yes, are you intending that at least some editing will be done on the image while it's encoded using sRGB primaries? Yes or no? With respect, Elle Stone ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
Elle Stone (ellest...@ninedegreesbelow.com) wrote: On 10/14/2014 07:52 AM, Øyvind Kolås wrote: On Tue, Oct 14, 2014 at 1:34 PM, Elle Stone ellest...@ninedegreesbelow.com wrote: To convert images to and from unbounded linear gamma sRGB, you MUST pass through XYZ. XYZ is the PCS. I remind you that linear RGB spaces are a single matrix multiplication away from other linear RGB spaces and XYZ. Matrix conversions between RGB working spaces can be concantenated. That concantenation goes through XYZ. It almost sounds like you want to obscure this fundamental distinction between XYZ and unbounded linear gamma sRGB. for conversions between RGB working spaces there is no fundamental distinction between XYZ and unbounded linear gamma sRGB. In mathematical terms both of these span up a three dimensional vector space (describing color) and the only difference is that they use different basis vectors. You can *easily* describe conversions between different RGB primaries with ulgsRGB as the connecting space (completely replacing XYZ). You would get a different set of transformation matrices of course. XYZ is something that has a special role for all of the non-RGB color spaces Lab, xyY, Luv etc, as well as operations like chromatic adaptation. Hence it makes sense to use it also as the connecting space for the different RGB primaries. Are you planning on converting non-sRGB images to unbounded linear gamma sRGB? Yes or no? For pixel storage we will use whatever fits our needs, it does not make sense at this point to specify this. This might be a Lab-buffer with a cache in front of it that has the pixels converted to sRGB. Or a Adobe-RGB-Buffer without a cache. Or unbounded linear gamma sRGB. Or whatever. The important thing is, that gegl/babl provides the means to access these data in whatever format is needed by the operation that is happening. A brightness-invert function might request the data in Lab, do the inversion on the L channel and feed the results back as Lab to the gegl/babl infrastructure, which will process it to provide the next operation in the graph with the input format the next operation needs. If yes, are you intending that at least some editing will be done on the image while it's encoded using sRGB primaries? Yes or no? That totally depends on the editing-operation in question and is orthogonal to the pixel memory storage format. Bye, Simon -- si...@budig.de http://simon.budig.de/ ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
Hi Thorsten. Thorsten Stettin (thorsten.stet...@gmail.com) wrote: with all due respect to you, I think you should contribute instead to babble. If you perceive Elles texts as babbling it seems that this discussion is way over your head and you might want to consider staying out of it. Thanks, Simon -- si...@budig.de http://simon.budig.de/ ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
On Tue, Oct 14, 2014 at 9:04 AM, Simon Budig si...@budig.de wrote: If you perceive Elles texts as babbling it seems that this discussion is way over your head and you might want to consider staying out of it. +1. I'll admit that this discussion is way over my head, but as it seems to involve only two people would it be better handled over a phone call? It appears that there are some basic assumptions that aren't in alignment. Chris ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
Christopher Curtis (ccurt...@gmail.com) wrote: I'll admit that this discussion is way over my head, but as it seems to involve only two people would it be better handled over a phone call? It appears that there are some basic assumptions that aren't in alignment. While it certainly could be more concise, the discussion has helped me tremendously with my glimpse into gegl/babl. So while the misunderstandings might be easier to overcome within a phone call keeping the discussion on the list helps with potentially getting the concepts out there to more people. That having said, meeting people in person *is* tremendously helpful and I'd like to extend pippins invitation to the LGM (next year in Toronto) to everybody who is interested in discussing these topics with e.g. pippin and me. There will be funds available to help bring people together. Bye, Simon -- si...@budig.de http://simon.budig.de/ ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
Am 14.10.2014 um 15:04 schrieb Simon Budig: Hi Thorsten. Thorsten Stettin (thorsten.stet...@gmail.com) wrote: with all due respect to you, I think you should contribute instead to babble. If you perceive Elles texts as babbling it seems that this discussion is way over your head and you might want to consider staying out of it. Thanks, Simon Ok, It pisses me off though. I didn't mean to hurt anybody. But we don't need any academic discussion. We need contribution. Ok, I'm just a packager, sorry for that. Cheers Thorsten -- Lao-Tse sagt: Nichtstun ist besser, als mit viel Mühe nichts zu schaffen. Und er sagt auch: Ich habe drei Schätze, die ich hüte und hege. Der eine ist die Liebe, der zweite ist die Genügsamkeit, der dritte ist die Demut. Nur der Liebende ist mutig, nur der Genügsame ist großzügig, nur der Demütige ist fähig zu herrschen. ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
+1 On 14 October 2014 15:54, Simon Budig si...@budig.de wrote: While it certainly could be more concise, the discussion has helped me tremendously with my glimpse into gegl/babl. So while the misunderstandings might be easier to overcome within a phone call keeping the discussion on the list helps with potentially getting the concepts out there to more people. ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
On Tue, Oct 14, 2014 at 9:54 AM, Simon Budig si...@budig.de wrote: While it certainly could be more concise, the discussion has helped me tremendously with my glimpse into gegl/babl. So while the misunderstandings might be easier to overcome within a phone call keeping the discussion on the list helps with potentially getting the concepts out there to more people. People seem to be getting frustrated and I don't think that helps anybody. It seems to me that realigning the conversation in a more appropriate medium would help to make the mailing list discussion more productive. A summary of the phone call would then either bring everyone back together, or continue the dispute on clearer terms. Of course, folks are free to do whatever... $0.02, Chris ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
Re: [Gimp-developer] [Gegl-developer] babl roadmap
Hi, On Tue, Oct 14, 2014 at 3:58 PM, Thorsten Stettin thorsten.stet...@gmail.com wrote: Am 14.10.2014 um 15:04 schrieb Simon Budig: Hi Thorsten. Thorsten Stettin (thorsten.stet...@gmail.com) wrote: with all due respect to you, I think you should contribute instead to babble. If you perceive Elles texts as babbling it seems that this discussion is way over your head and you might want to consider staying out of it. Thanks, Simon Ok, It pisses me off though. I didn't mean to hurt anybody. But we don't need any academic discussion. Of course we do! These kind of discussions are really helpful to understand things. Most of these are also over my head (though I wish I understood more of these!) but I am very grateful that they are done in the open! This is also part of what makes a sane Free Software. Now of course, meeting people in LGM or elsewhere is also very good, but that should not prevent the results of these discussions to also be discussed publicly here. Same if it were by phone, I would still always appreciate discussions to be summarized or continued on the mailing list. We need contribution. Seriously if you don't consider these extremely important contributions for GIMP (discussion on a good architecture for what is essentially the core of GIMP!), I wonder what will be! Of course code contributions *too* is nice, but these happen after the discussions in such cases. Anyway please, this is the gimp-developer@ mailing list. If you don't like these discussions about improving the core of GIMP, maybe you are on the wrong list. Also you don't have to read them all! (there are a lot which I don't find interesting just by reading the title, I don't ask people to not write them!). As long as everybody stays polite and remembers we are on a written medium (hence misunderstandings and annoyed feelings are easier to get; when that happens, just breath), please don't interrupt completely on-topic discussions. Thanks. Jehan Ok, I'm just a packager, sorry for that. Cheers Thorsten -- Lao-Tse sagt: Nichtstun ist besser, als mit viel Mühe nichts zu schaffen. Und er sagt auch: Ich habe drei Schätze, die ich hüte und hege. Der eine ist die Liebe, der zweite ist die Genügsamkeit, der dritte ist die Demut. Nur der Liebende ist mutig, nur der Genügsame ist großzügig, nur der Demütige ist fähig zu herrschen. ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list ___ gimp-developer-list mailing list List address:gimp-developer-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list List archives: https://mail.gnome.org/archives/gimp-developer-list
