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> I’d be curious to hear what reasons you have to use Jzazbz I needed a color space for teaching, so I'm using it to kludge wide-gamut hue linearity onto CAM16

> I’d be curious to hear what reasons you have to use Jzazbz I needed a color space for teaching, so I'm using it to kludge wide-gamut hue linearity onto CAM16UCS. I wish I knew of something better to do. Backstory is, I've long struggled to find community of interested and discussion, around the idea of transformatively improving science education content by collaboratively applying vastly greater-than-usual domain expertise. I thought to troll with a worked example, and chose "color". Even though "I'm building hard thing solo, because I really don't want to build such things solo?!?"... sigh. Color is pervasively taught in early primary, but with such poor content and outcomes, that foundational confusion persists even among first-tier physical-sciences graduate students. So: might color be taught more clearly by emphasizing spectra, in early primary? With web interactives? It seemed a question to explore. So I needed a perceptual color space optimized for learning color. A rather different objective than usually drives color space design. Computability doesn't matter, as small lookup tables suffice. But noticeable features from eyeballing the space should be "yes, that's color perception", not "oh, no, that's an artifact of the model - try to ignore that aspect". The usual art/science education "one part careful, nine+ parts misleading bogosity" just doesn't end well. CAM16UCS is generally good at avoiding "that... doesn't look plausible". Better than other UCSs I skimmed. But... hue gets curvy near its edges, especially badly in blue. Jzazbz regrettably fails the "space looks plausible" test, but is wide-gamut, and has nice hue linearity. So I'm using it to kludge greater linearity onto CAM16UCS, between sRGB gamut and visible boundary. Which aids understandably coupling space to spectra. Getting from daylight to banana to spectra and apparent spectra and color space, provides a lot of opportunity to get things wrong. And from interactive draw-a-spectra. Swapping in Jzazbz for end-to-end HDR physical units provides the warm fuzzy of sanity check. Thus three.js intensities in nits, and an opportunity for Sunday punning. It's just a silly niche use case, rather than advanced use, but modulo burn out, I'll be back at it tomorrow. Also... there's an order-of-magnitude luminance "why don't you see a sky full of stars" interactive somewhere on my infinite todo list, so getting perceptual luminace right had additional motivation. Though that will have to handle meso and scotopic perception... sigh. Appreciated your comments.

dahart 4y ago
Hey that’s really cool and not silly or niche at all, I actually think it’s extra advanced to not just understand color so deeply but try to teach it at that level. Pretty hard core in my book, color is a surprisingly hard and deep subject. I had a few good teachers along the way who taught me a ton about color and computer graphics. Peter Shirley is probably the top of my personal list, and he’s also very interested in improving science education, so maybe worth checking out his CG books. In his rendering class we bought a MacBeth color checker and had to take a photograph of it set inside a scene that we physically built out of whatever materials and light sources we wanted, and then we had to write our own renderers to match the photo. You really learn a lot about color trying to do that! :) Pete and I have since designed a simple opponent-process color space aimed at ease of use that is perceptually uniform ‘enough’, but we haven’t published it yet. That could be a fun way to teach though: have students design their own color space! There also might be some interesting work going on in the area of digital color picker interfaces that could be useful for teaching. I’m forgetting who does this stuff, so can’t cough up any links at the moment, but I’ve definitely seen a couple of neat presentations recently that combine the science of perception and color spaces along with good design sensibilities to make interfaces that are demonstrably better for artists than the crappy RGB & HSV & other pickers we usually see today.
- mncharity 4y ago
  > color is a surprisingly hard and deep subject Oh yeah. I was (hmm, am) hoping to dig out some limited cluster of concepts that gells as "oh, that's fun, and I'd very not have thought you could teach that, or that way". Eg xkcd color name regions in a voxelized color space as "learn color names" K-1 worksheet. Trying for a "light"(spectra) vs "color"(human perception) distinction, limiting scope on perception to early primary color topics. Science education rarely does deep, integrated, or usable, so it's rather an open question what might be possible. And without a vision of that, there's little incentive for funding or exploring other than incremental improvement. Even aside from creation pragmatics. "A big onboarding welcome to all our new science textbook author staff! Worry not that you are fresh liberal arts graduates, with no science background at all, for we've A Scientist on call!"(paraphrased) > a simple opponent-process color space Ah, neat. That could be fun. Given my focus on spectra, I was also tempted by IGPGTG's "build on Gaussian spectra", but pruned. > have students design their own color space! Oh, there's an intriguing idea. I'd though as far as "if I can't find a color space without misleading large artifacts, I'll have to offer a diverse swappable several, if students are to have any hope of distinguishing data from noise". But a direct manipulation "create your own color space"... hmmm. Perhaps evaluated with visual metrics? Like gradients for linearity. Or mixing for Euclidean-ness and hue order - reorder a hue circle, and get weirdness in the in-betweens? Neat approach - not "this is just how it is" but "hands on, you'll find this a sweet spot". Hmm, if say, "Pink is the most important color! So its variants should be the focus of my space!"... what might that look like? A "pink-set" of color names? Eg, not "green" but "anti-magenta"? Not "white" but "palest pink"? :) I so miss pre-covid brainstorming like this at MIT. :/ > a couple of neat presentations recently that combine the science of perception and color spaces along with good design sensibilities to make interfaces that are demonstrably better for artists Very neat. If a link surfaces, I'd be interested. There's some work on simulating pigment spectra and interaction for "physically realistic" painting, and I wondered at their UI. And if a MVP web app with such, might serve as hands-on antidote to the "subtractive rules are peers to additive" misconception. > take a photograph of it set inside a scene that we physically built I wondered how controlled lighting (filter gell on box, discrete LEDs, and tablets getting the narrow spectra of quantum-dot displays) might be leveraged. Eg, "sketch what you think this page/thing/scene will look like if lit like X, then try it and describe it, and take a picture"? And sketched, sort of a point renderer - a block ui for playing with spectra. Eg, a Sun block, realistically pictured with red-tinted rim on white, with a spectra and white color", passed though atmosphere block set at angle X, with this transmittance/reflectance/florescence strip, yielding this spectra and color, lighting this point on a multispectral image of fruit, with/yielding ditto. Seen by this camera to get rgb, shown by this display to get this spectra. Banana vs banana pixel. Filters, bounced sources, etc. And then perhaps challenges of "assemble blocks to get a spectra like this". Or to light this multispectral MacBeth or scene to match this snapshot. Or bantering, "your freehand or musically-keyboarded spectra looks like this strawberry icecream with blue M&Ms". A hands-on way to address the many misconceptions around lighting and color. And then there's video shaders, filtering or fragmenting by color space and names, for interacting with color in the environment. And... the minor challenge of finding a coherent MV"P" in all of this. :)

dahart 4y ago

Hey that’s really cool and not silly or niche at all, I actually think it’s extra advanced to not just understand color so deeply but try to teach it at that level. Pretty hard core in my book, color is a surprisingly hard and deep subject. I had a few good teachers along the way who taught me a ton about color and computer graphics. Peter Shirley is probably the top of my personal list, and he’s also very interested in improving science education, so maybe worth checking out his CG books. In his rendering class we bought a MacBeth color checker and had to take a photograph of it set inside a scene that we physically built out of whatever materials and light sources we wanted, and then we had to write our own renderers to match the photo. You really learn a lot about color trying to do that! :) Pete and I have since designed a simple opponent-process color space aimed at ease of use that is perceptually uniform ‘enough’, but we haven’t published it yet. That could be a fun way to teach though: have students design their own color space! There also might be some interesting work going on in the area of digital color picker interfaces that could be useful for teaching. I’m forgetting who does this stuff, so can’t cough up any links at the moment, but I’ve definitely seen a couple of neat presentations recently that combine the science of perception and color spaces along with good design sensibilities to make interfaces that are demonstrably better for artists than the crappy RGB & HSV & other pickers we usually see today.

mncharity 4y ago
> color is a surprisingly hard and deep subject Oh yeah. I was (hmm, am) hoping to dig out some limited cluster of concepts that gells as "oh, that's fun, and I'd very not have thought you could teach that, or that way". Eg xkcd color name regions in a voxelized color space as "learn color names" K-1 worksheet. Trying for a "light"(spectra) vs "color"(human perception) distinction, limiting scope on perception to early primary color topics. Science education rarely does deep, integrated, or usable, so it's rather an open question what might be possible. And without a vision of that, there's little incentive for funding or exploring other than incremental improvement. Even aside from creation pragmatics. "A big onboarding welcome to all our new science textbook author staff! Worry not that you are fresh liberal arts graduates, with no science background at all, for we've A Scientist on call!"(paraphrased) > a simple opponent-process color space Ah, neat. That could be fun. Given my focus on spectra, I was also tempted by IGPGTG's "build on Gaussian spectra", but pruned. > have students design their own color space! Oh, there's an intriguing idea. I'd though as far as "if I can't find a color space without misleading large artifacts, I'll have to offer a diverse swappable several, if students are to have any hope of distinguishing data from noise". But a direct manipulation "create your own color space"... hmmm. Perhaps evaluated with visual metrics? Like gradients for linearity. Or mixing for Euclidean-ness and hue order - reorder a hue circle, and get weirdness in the in-betweens? Neat approach - not "this is just how it is" but "hands on, you'll find this a sweet spot". Hmm, if say, "Pink is the most important color! So its variants should be the focus of my space!"... what might that look like? A "pink-set" of color names? Eg, not "green" but "anti-magenta"? Not "white" but "palest pink"? :) I so miss pre-covid brainstorming like this at MIT. :/ > a couple of neat presentations recently that combine the science of perception and color spaces along with good design sensibilities to make interfaces that are demonstrably better for artists Very neat. If a link surfaces, I'd be interested. There's some work on simulating pigment spectra and interaction for "physically realistic" painting, and I wondered at their UI. And if a MVP web app with such, might serve as hands-on antidote to the "subtractive rules are peers to additive" misconception. > take a photograph of it set inside a scene that we physically built I wondered how controlled lighting (filter gell on box, discrete LEDs, and tablets getting the narrow spectra of quantum-dot displays) might be leveraged. Eg, "sketch what you think this page/thing/scene will look like if lit like X, then try it and describe it, and take a picture"? And sketched, sort of a point renderer - a block ui for playing with spectra. Eg, a Sun block, realistically pictured with red-tinted rim on white, with a spectra and white color", passed though atmosphere block set at angle X, with this transmittance/reflectance/florescence strip, yielding this spectra and color, lighting this point on a multispectral image of fruit, with/yielding ditto. Seen by this camera to get rgb, shown by this display to get this spectra. Banana vs banana pixel. Filters, bounced sources, etc. And then perhaps challenges of "assemble blocks to get a spectra like this". Or to light this multispectral MacBeth or scene to match this snapshot. Or bantering, "your freehand or musically-keyboarded spectra looks like this strawberry icecream with blue M&Ms". A hands-on way to address the many misconceptions around lighting and color. And then there's video shaders, filtering or fragmenting by color space and names, for interacting with color in the environment. And... the minor challenge of finding a coherent MV"P" in all of this. :)