July 2020 - colorsync-users

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. >

8 18

Re: Print without color management in CS Utility
by David Wollmann 07 Jul '20

07 Jul '20

Hi, On further examination, if you simply go to the popup, "Color Matching” select the radio button for ColorSync and disable Automatic–pick any RGB profile–then go back and select “Print as Target” … when you now return to Color Matching, ColorSync is grayed out as one would expect. It is not necessary to setup a null transform for “Print as Target” to be active. So, perhaps this is a bug? David Wollmann > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 6 Jul 2020 07:58:56 -0600 > From: Andrew Rodney <andrew(a)digitaldog.net> > To: "'colorsync-users?lists.apple.com' List" > <colorsync-users(a)lists.apple.com> > Subject: Print without color management in CS Utility > Message-ID: <7A1A759E-62AD-418A-9442-E7142F92A5DB(a)digitaldog.net> > Content-Type: text/plain; charset=utf-8 > > Using Catalina. Used to be able to print without color management. Can?t find any settings that make the ?Print as Target: dropdown option not grayed out. > Bug or I?m missing something? > > TIA > > Andrew Rodney > http://www.digitaldog.net/ <http://www.digitaldog.net/> > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > colorsync-users mailing list > colorsync-users(a)lists.apple.com > https://lists.apple.com/mailman/listinfo/colorsync-users > > > ------------------------------ > > End of colorsync-users Digest, Vol 17, Issue 74 > *********************************************** >

2 1

Re: colorsync-users Digest, Vol 17, Issue 74
by David Wollmann 07 Jul '20

07 Jul '20

Hi, the only way I got it to work was to match the target profile to what ColorSync is using under Color Matching, set up a null transform. ColorSync Matching can’t be set to Automatic. I tried assigning Adobe RGB to the target and in ColorSync Matching and also assigned an Epson media profile to target and in ColorSync Matching, both caused the desired popup to become available. Not elegant or ideal. Thanks, David Wollmann > Message: 1 > Date: Mon, 6 Jul 2020 07:58:56 -0600 > From: Andrew Rodney <andrew(a)digitaldog.net> > To: "'colorsync-users?lists.apple.com' List" > <colorsync-users(a)lists.apple.com> > Subject: Print without color management in CS Utility > Message-ID: <7A1A759E-62AD-418A-9442-E7142F92A5DB(a)digitaldog.net> > Content-Type: text/plain; charset=utf-8 > > Using Catalina. Used to be able to print without color management. Can?t find any settings that make the ?Print as Target: dropdown option not grayed out. > Bug or I?m missing something? > > TIA > > Andrew Rodney > http://www.digitaldog.net/ <http://www.digitaldog.net/> >

1 0