May 2020 - colorsync-users - lists.apple.com

Re: Humans (and cameras and scanners) do not have a color gamut (?)
by Rich Wagner 19 Oct '20

19 Oct '20

I agree with Florian’s responses below regarding how we “know” what animals “see.” The parallel question is how we “know” what women with tetrachromatic vision “see.” There is a very good article from the BBC that describes this that might help. https://www.bbc.com/future/article/20140905-the-women-with-super-human-visi… Here’s a short excerpt from the excellent story: Proving that these people actually see the world differently has involved a two-decade journey, however. Although the relevant combination of genes does not seem to be especially rare – perhaps 12% of women might have four distinct cones – many of the people that Jordan tested just didn’t seem to show any differences in their perception. But by 2010, she had found a subject who perfectly acted the part of a tetrachromat. Jordan’s “acid test” involved coloured discs showing different mixtures of pigment, such as a green made of yellow and blue. The mixtures were too subtle for most people to notice: almost all people would see the same shade of olive green, but each combination should give out a subtly different spectrum of light that would be perceptible to someone with a fourth cone. Sure enough, Jordan’s subject was able to differentiate between the different mixtures each time <http://www.journalofvision.org/content/10/8/12.full>. “When you ask them to discriminate between the two mixtures, a tetrachromat can do it very quickly. They don’t hesitate,” says Jordan. Unfortunately, much of the research in color perception is highly complex and often difficult for the lay public to comprehend. Good science writers can translate that research into language the lay public can understand. Poor science writing leads to exaggerated claims and misinformation. That said, the title of this article is a bit over the top. I don’t think these women have “super human vision” any more than those who are colorblind have “sub human vision.” Both have visual perception that is significantly different from the average of our species. —Rich > OnMon, 13 Jan 2020 19:40:11 +0100, Florian Hoech <lists+colorsync-users(a)hoech.org <mailto:lists+colorsync-users@hoech.org>> wrote: > [snip] >> Not a single case can be made by anyone?s fisthand information about the post processing by the brains of these animals. Who can know what they see or apprehend? > > You can draw pretty useful conclusions (meaning they work well in > real-life, thus supporting the respective theories) from all the > scientific research that has been done. "Color" perception is not just > "nice to have". Trichromats (like humans) have an evolutionary edge over > (say) dichromats, e.g. when it comes to distinguish edible/nutritious > from inedible/less nutritious food like fruits etc. When you look at the > M and L cone responses of any trichromat, you can see that the responses > of the "sensors" (cones) largely overlap. Yet, we seem to perceive the > "end result", green and red, as very different colors (opposites even!). > >> Since humans communicate with each other about color we can build models and references and so on. But animals? Yet, experts are quick to supply examples of how things must appear to non-humans. > > I think you may be conflating the actual research with how it is > presented (usually not by the researchers themselves), broken down and > simplified in newspapers/magazines/articles, online and offline, meant > for consumption by the general public. > >> When we grant that all of these theories are onto something about the ways animals percieve color we account for their differences by describing them in terms of ?gamuts?. > > I like the term "dimensions". A Tetrachromat has an additional dimension > of "color". > >> Surprise: experts determine gamuts based on the sensor alone! They don?t even seem to be the slightest bit unhappy about it. > > ...where? And who? Dimensionality alone doesn't really tell us much > about gamuts. > > Florian. >

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Scanner Profiling Issue
by Chase 15 May '20

15 May '20

Hi, I've been trained to profile digital devices by (after calibration) first turning off all color management meaning no profile application to the output, making a "raw" output and opening it in a profiling application to make an ICC input profile. I'm running into a problem trying to profile a scanner whose software interface will not allow you to turn off the color management on any scan. I was told by the manufacturer to just discard the embedded profile (in Photoshop) prior to creating and opening the now supposed "raw" scan used to make a profile in Xrite or other applications. When tested in Photoshop, the supplied initial embedded profile supplied and recommended to use during profiling by the manufacturer raised all the "L" values about seven "L" so it did change the "raw" values of the scanner for every scan. To my mind, if a "raw" scan is not truly "raw," it will not profile correctly. Testing the resulting new input profile had problems with tone values, gray and color hues. Therefore, their assumption of just discarding a profile in Photoshop will not create a truly "raw scan?" I have not seen it. Any ideas? Is there any way I can traditionally profile this type of scanner? That is the problem I am trying to solve. Thanks for your opinion, Randy ZauchaManaged Color

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IS&T CIC28 to move Online—Extended Submission Deadlines & More
by Roberta Morehouse 14 May '20

14 May '20

The IS&T Twenty-eighth Color and Imaging Conference (CIC28) is now an online event! What does this mean for you? *The elimination of travel expenses *Flexibility around time off from work to attend the online conference *More time to submit your research TOPICS: image quality * perception * capture * display * print * material appearance * theory * multispectral imaging * illumination * applications REVISED DEADLINES · Journal-first Submission (JPI or JIST): 1 June 2020 · Proceedings Paper: 30 June 2020 Accepted Proceedings Manuscripts Due: 14 September 2020 · Workshop & Short Course Proposals: 15 June 2020 Submit your paper, workshop, or short course proposals today! http://bit.ly/CIC28_CFP CIC28 ONLINE 2-13 November 2020 http://bit.ly/CIC28_ Follow us on LinkedIn & @ImagingOrg for #CIC28 for updates Roberta Morehouse, CMP Marketing Manager Society for Imaging Science and Technology (IS&T) www.imaging.org

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SNAP 2009 Profile and PDFs
by PPS Lists 13 May '20

13 May '20

I’ve got an odd thing happening with making PDFs with documents created using the SNAP 2009 ICC profile. For context, here’s what I can successfully do with other profiles, but does not work with SNAP 2009. 1. Create a blank CMYK document in Photoshop and assign any CMYK profile (set aside SNAP 2009 for now). 2. Create a black box – 100% K only. 3. Create a red box – 100% M and 70% Y. 4. Save as a Photoshop PDF using either Convert to Destination using the same profile as the destination, or No Conversion. 5. Open the PDF in Acrobat and examine it with Output Preview in Print Production. Every time the color numbers will not have changed from the values above, as expected. Day in and day out I can successfully do this except - when I use SNAP 2009. With SNAP 2009 the 100% K box gets converted to 4-color and the red values change as well. If I save the file as Photoshop EPS and run it through Distiller the problem goes away and the color numbers do not change. I also don’t experience this with Illustrator. Has anyone else come across this? This is the only profile that I had this happen with (so far). --- Gary Smith

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Lab -> RGB
by Jeff Nova 07 May '20

07 May '20

Hi friends, We have a web application and want to display the best previews we can for Lab images, which are not supported by any browser. The Lab we expect is the default Lab from Photoshop, which I think is D50. So, what is the best choice for RGB space? We are tagging the files, and prefer v2 profiles for more browser compatibility, but will do v4 is needed. I don't need help in the transformation - I just want to know the best RGB space to present the widest gamut resembling Lab as possible. I assume one of the best choices is Don's MaxRGB? http://www.hutchcolor.com/profiles.html I welcome any input! Very best, Jeff -- Jeff NovaChief Executive OfficerColorhythm jnova(a)colorhythm.comMain: +1 415-399-9921Direct: +1 415-399-9921 x407Mobile: +1 510-710-9590Fax: +1 415-399-9928 1015 Battery Street, Suite CSan Francisco CA 94111http://colorhythm.com Please consider our environmentbefore printing this email Colorhythm is a certified Green Business: This electronic mail and the documents accompanying it are considered trade secret, confidential and/or proprietary by Colorhythm LLC. This information is intended for use by the individual or entity to whom this e-mail is addressed. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited.

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RE: Lab -> RGB
by graxx＠videotron.ca 07 May '20

07 May '20

Worth giving it a try, Jeff. Don't want to sound like a naysayer or a pessimist but put a sample of those wider gamut Eizo, ASUS, BenQs and iMacs calibrated at 2.2gamma, D65 and 120cm2, next to each other on a table and please let us know how they compare visually, across a range of browsers? That ought to be the ultimate test IMO. (Wish I had the resources to do this kind test myself) Still, I don't see the argument for AdobeRGB over sRGB *unless* the bulk of your images have deep, saturated colors? It is a well-known fact, for example, that subjects like "people" don't require a whole lot of gamut. / Roger -----Original Message----- From: Jeff Nova via colorsync-users <colorsync-users(a)lists.apple.com> Sent: Wednesday, May 6, 2020 11:30 PM To: Andrew Rodney <andrew(a)digitaldog.net> Cc: 'colorsync-users?lists.apple.com' List <colorsync-users(a)lists.apple.com> Subject: Re: Lab -> RGB My creative users will be using modern browsers with color management and wider gamut displays like Eizo, ASUS pro-graphics (both sRGB and Adobe), BenQs (Adobe), and iMacs (presumably P3). All calibrated to 2.2gamma, D65, and 120cm2. We will have occasional business users on old PCs and older browsers but I need to serve the former’s needs, not the latter’s. I’m considering creating untagged sRGB fallbacks for everything and allow the user to choose in a preference but that’s expensive resource wise. - J > On May 6, 2020, at 7:12 PM, Andrew Rodney via colorsync-users <colorsync-users(a)lists.apple.com> wrote: > > > >> On May 6, 2020, at 8:00 PM, Henry Davis via colorsync-users <colorsync-users(a)lists.apple.com> wrote: >> >> IF.?. Sounds like assumptions are still big in play. >> >> Henry Davis > > Indeed, there’s a big world of non color management in terms of browsers (although less so), some require users to turn on color management (Dumb). Some folks are still working on old operating systems with really old browsers. > Now the Jeff did mention briefly his target audience and perhaps (IF again), they are all using color managed browsers. Only Jeff can tell us for sure. > > Andrew Rodney > http://www.digitaldog.net/ > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > colorsync-users mailing list (colorsync-users(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/colorsync-users/jnova%40colorh > ythm.com > > This email sent to jnova(a)colorhythm.com -- Jeff NovaChief Executive OfficerColorhythm jnova(a)colorhythm.comMain: +1 415-399-9921Direct: +1 415-399-9921 x407Mobile: +1 510-710-9590Fax: +1 415-399-9928 1015 Battery Street, Suite CSan Francisco CA 94111http://colorhythm.com Please consider our environmentbefore printing this email Colorhythm is a certified Green Business: This electronic mail and the documents accompanying it are considered trade secret, confidential and/or proprietary by Colorhythm LLC. This information is intended for use by the individual or entity to whom this e-mail is addressed. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited.

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Re: Lab -> RGB (Jeff Nova)
by Malcolm Mackenzie 07 May '20

07 May '20

Re: Lab -> RGB (Jeff Nova) I?m considering creating untagged sRGB fallbacks HI Jeff whatever colorspace you use it's better to tag the images, the overhead is tiny and ensures a CM system correctly display it. My 2 cents Malcolm Mackenzie

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RE: Lab -> RGB
by graxx＠videotron.ca 07 May '20

07 May '20

I don't see how you could go wrong with sRGB, ntil the day more people are looking at the web through wide gamut displays, be it tablets or monitors. My two cents, Roger Breton www.graxx.ca -----Original Message----- From: Jeff Nova via colorsync-users <colorsync-users(a)lists.apple.com> Sent: Wednesday, May 6, 2020 8:01 PM To: colorsync-users(a)lists.apple.com Subject: Lab -> RGB Hi friends, We have a web application and want to display the best previews we can for Lab images, which are not supported by any browser. The Lab we expect is the default Lab from Photoshop, which I think is D50. So, what is the best choice for RGB space? We are tagging the files, and prefer v2 profiles for more browser compatibility, but will do v4 is needed. I don't need help in the transformation - I just want to know the best RGB space to present the widest gamut resembling Lab as possible. I assume one of the best choices is Don's MaxRGB? http://www.hutchcolor.com/profiles.html I welcome any input! Very best, Jeff -- Jeff NovaChief Executive OfficerColorhythm jnova(a)colorhythm.comMain: +1 415-399-9921Direct: +1 415-399-9921 x407Mobile: +1 510-710-9590Fax: +1 415-399-9928 1015 Battery Street, Suite CSan Francisco CA 94111http://colorhythm.com Please consider our environmentbefore printing this email Colorhythm is a certified Green Business: This electronic mail and the documents accompanying it are considered trade secret, confidential and/or proprietary by Colorhythm LLC. This information is intended for use by the individual or entity to whom this e-mail is addressed. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited.

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RE: Lab -> RGB
by graxx＠videotron.ca 07 May '20

07 May '20

Wayne, I don't suppose clipboard formats (on PC and Mac) are smart enough to have a field for "color space"? Clipboards can hold text or images. / Roger -----Original Message----- From: Wayne Bretl via colorsync-users <colorsync-users(a)lists.apple.com> Sent: Wednesday, May 6, 2020 11:04 PM To: 'Jeff Nova' <jnova(a)colorhythm.com>; colorsync-users(a)lists.apple.com Subject: RE: Lab -> RGB Well, one good thing came out of this - I did a quick test with Chrome on my Windows 10 PC, moving an sRGB web image (viewed on Flickr in Chrome) between my sRGB monitor and wide gamut monitor, and the color management is working. I have no idea when this started to be the case. On the other hand, color management also works in Photoshop when I move a window from one monitor to the other. On the third hand, Photoshop does not recognize that the image, copied from Flickr to the clipboard, is sRGB and ask what I want to do when I open a new file and paste in Photoshop; it instead applies my default working space. I have to assign sRGB manually. It appears the color space info is lost in the Clipboard app. Normally, photos from (some) other sources will be recognized as not In the default space, and Photoshop will ask which space to use. So, I will still watch my step, as some pitfalls in color management have not been fixed. -----Original Message----- From: Wayne Bretl via colorsync-users <colorsync-users(a)lists.apple.com> Sent: Wednesday, May 06, 2020 6:07 PM To: 'Jeff Nova' <jnova(a)colorhythm.com>; colorsync-users(a)lists.apple.com Subject: RE: Lab -> RGB Please clarify "web application." Is it going to display in a web browser? Many web browsers are not color managed and will ignore color space information, and assume the color space is sRGB. -----Original Message----- From: Jeff Nova via colorsync-users <colorsync-users(a)lists.apple.com> Sent: Wednesday, May 06, 2020 5:01 PM To: colorsync-users(a)lists.apple.com Subject: Lab -> RGB Hi friends, We have a web application and want to display the best previews we can for Lab images, which are not supported by any browser. The Lab we expect is the default Lab from Photoshop, which I think is D50. So, what is the best choice for RGB space? We are tagging the files, and prefer v2 profiles for more browser compatibility, but will do v4 is needed. I don't need help in the transformation - I just want to know the best RGB space to present the widest gamut resembling Lab as possible. I assume one of the best choices is Don's MaxRGB? http://www.hutchcolor.com/profiles.html I welcome any input! Very best, Jeff -- Jeff NovaChief Executive OfficerColorhythm jnova(a)colorhythm.comMain: +1 415-399-9921Direct: +1 415-399-9921 x407Mobile: +1 510-710-9590Fax: +1 415-399-9928 1015 Battery Street, Suite CSan Francisco CA 94111http://colorhythm.com Please consider our environmentbefore printing this email Colorhythm is a certified Green Business: This electronic mail and the documents accompanying it are considered trade secret, confidential and/or proprietary by Colorhythm LLC. This information is intended for use by the individual or entity to whom this e-mail is addressed. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited. _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/waynebretl%40cox.net This email sent to waynebretl(a)cox.net _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx(a)videotron.ca

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RE: Lab -> RGB
by graxx＠videotron.ca 07 May '20

07 May '20

Wire, We all know there is no such thing as an "absolute" AdobeRGB, as there is no such thing as an absolute "P3" or absolute "sRGB" monitor, regardless of brands or models or calibrations or profiling: put ten "AdobeRGB-calibrated monitors" next to each other, they are bound not to show the same exact colors, and we all know the reasons why, LCD vs LED vs IPS vs instrumentation.... True, the better brands have reliable factory calibration out of the box, which don't last forever, mind you. And even then... And what about the rest? And who knows how a "creative professional" might modify his/her monitor settings to "suit his/her taste"? I've seen people change their settings behind my back... I think the case can be made for whatever "RGB" space Jeff wants to use, it depends on his religion which I'll respect. / Roger -----Original Message----- From: Wire ~ via colorsync-users <colorsync-users(a)lists.apple.com> Sent: Wednesday, May 6, 2020 9:40 PM To: 'colorsync-users?lists.apple.com' List <colorsync-users(a)lists.apple.com> Subject: Re: Lab -> RGB Reading your question carefully, you've asked for the widest gamut you can get assuming a Lab source. Have you evaluated how much of Lab your catalog actually requires? Roger's (et al) point about value of sRGB assumption, even though somewhat restrictive, carries the day in my view. But I sense you already know and have a reason for why that's not sufficient... So what are your rendering assumptions? I'll take a chance and offer a perspective on displays: Given the commodities display market and the status of wide gamut today, where new TV displays are reaching for but usually missing Rec.2020, that would seem to be an appropriate max. For desktop computer displays, Display P3 (Adobe Image P3) which is sRGB gamma is a practical compromise between a significant additional (and balanced) extension to gamut with not-too-risky backwards compatibility to sRGB w3c. It won't be outlandish if viewed wrong but sRGB viewers will notice dull saturation. DCI-P3 is to be avoided due to gamma 2.6. Graceful handling of tonal response should be considered as important as gamut, do that narrows the field quite a lot for backwards compat. You've gotta think of both. Rec.2020 is nominally 2.4, pretty close but significant variance from w3c sRGB The safety of sRGB I consider very desirable. While it leaves some real-world gamut on the table, no one is likely to miss it unless they know exactly what to look for. An image in a wide-gamut space that is incorrectly rendered due to lax ICC support is very likely to be noticed! I don't intend to be purely contrary when I regard Adobe RGB as a one-off space that can't be justified in any generally hygienic view of display color. It was an error when it was created that was never corrected, and is being forgotten with Display P3. If you haven't reviewed Lindbloom chart, it helps get space performance re Lab into a bit of perspective http://www.brucelindbloom.com/index.html?WorkingSpaceInfo.html The critical question I would consider: Will your target be a display? Or another app with subsequent processing? If former, sRGB is safest If latter, then pick the largest space that contains your catalog, but no larger, and tend towards G2.2 TRC. ECI RGB v2 with L* TRC, a D50 whitepoint and a wider gamut might make sense. It not likely to waste bits on color that will never be used, minimizing noise injection. FWIW Yours /wire On Wed, May 6, 2020 at 5:00 PM Jeff Nova via colorsync-users < colorsync-users(a)lists.apple.com> wrote: > Hi friends, > > > We have a web application and want to display the best previews we can > for Lab images, which are not supported by any browser. The Lab we > expect is the default Lab from Photoshop, which I think is D50. So, > what is the best choice for RGB space? We are tagging the files, and > prefer v2 profiles for more browser compatibility, but will do v4 is > needed. I don't need help in the transformation - I just want to know > the best RGB space to present the widest gamut resembling Lab as possible. > > > I assume one of the best choices is Don's MaxRGB? > > > http://www.hutchcolor.com/profiles.html > > > I welcome any input! > > > Very best, > Jeff > > > -- > Jeff NovaChief Executive OfficerColorhythm > jnova(a)colorhythm.comMain: +1 415-399-9921Direct: +1 415-399-9921 > x407Mobile: +1 510-710-9590Fax: +1 415-399-9928 > > 1015 Battery Street, Suite CSan Francisco CA > 94111http://colorhythm.com > > Please consider our environmentbefore printing this email Colorhythm > is a certified Green Business: > > This electronic mail and the documents accompanying it are considered > trade secret, confidential and/or proprietary by Colorhythm LLC. This > information is intended for use by the individual or entity to whom > this e-mail is addressed. If you are not the intended recipient, be > aware that any disclosure, copying, distribution or use of the > contents of this information is prohibited. > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > colorsync-users mailing list (colorsync-users(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > > https://lists.apple.com/mailman/options/colorsync-users/wire%40lexipha > nicism.com > > This email sent to wire(a)lexiphanicism.com > _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx(a)videotron.ca

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