Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

New Map Scale Is More Readable by People Who Are Color Blind

scientificamerican.com

Post reply on HN
Print view View original

21–30 of 52 posts

Re: New Map Scale Is More Readable by People Who Are Color Blind

#21

Post by driax »

DangerousPie wrote: post #18

Isn't this almost the same as the viridis palette that has been around for ages? https://cran.r-project.org/web/packages/viridis/vignettes/in...

I just skimmed the paper [1], and their conclusion starts:

> We identified one colormap in particular to be optimal for viewing by those with or without CVD, which we name cividis (Figs 4 and 5), generated by optimizing the viridis colormap and selecting the J' linearization that maximizes the range of J'. We chose this map due to its wide range of colors, resulting from a wide range of J0 values while still changing b0 significantly, and overall sharpness when overlaid onto complex images.

So pretty closely related :)

[1] https://arxiv.org/ftp/arxiv/papers/1712/1712.01662.pdf

Re: New Map Scale Is More Readable by People Who Are Color Blind

#22

Post by anc84 »

DangerousPie wrote: post #18

Isn't this almost the same as the viridis palette that has been around for ages? https://cran.r-project.org/web/packages/viridis/vignettes/in...

Their abstract explains things better: http://journals.plos.org/plosone/article?id=10.1371/journal....

They built a tool for any colormap. And then used it on Viridis. The result is this Cividis.

http://journals.plos.org/plosone/article/figure/image?size=l...

Re: New Map Scale Is More Readable by People Who Are Color Blind

#23

Post by pbhjpbhj »

With just two colours it's hard to see the intermediate values because our eyes tend to blur together colours; is that an intermediate value or sharp edge that I'm seeing fuzzily due to poor focus? With an intermediate tone, such issues are pushed down to lower resolutions - with yellow-red-blue I know for sure that if it's red it's an intermediate, but is the orange area a mix of lots of small yellow and red domains or is it a field of intermediate domains?

Rinse and repeat.

The article seems to say "this scale is better" whilst also describing how other scales can be better. The evidence they present says to me "choose scales according to the data, the desired use, and the observer", of you ship the data used to cover a visualisation along with that visualisation then people can use their own scale altered to the purposes (and disabilities) they have.

Re: New Map Scale Is More Readable by People Who Are Color Blind

#24

Post by mrob »

superkuh wrote: post #6

The image at the top of the page loads fine. But the rest an so encumbered with Javascript to load you literally have to reload the page at least 4 times (to load the JS domain, that loads the JS domain, that loads the JS domain) to see them. I gave up and closed the tab.

Works for me with JavaScript disabled in Firefox. I'm not seeing anything in the source that would cause problems either.

Re: New Map Scale Is More Readable by People Who Are Color Blind

#25

Post by brianmcc »

I am always pleased to see annoucements and discussions on colour blindness.

Forgive me for sharing again my writeup on this syndrome from my own experience, if you don't yourself have any such deficiencies you might find it interesting!

https://mcconnellsoftware.github.io/colourblind-in-software-...

Re: New Map Scale Is More Readable by People Who Are Color Blind

#26

Post by IanCal »

kozhevnikov wrote: post #12
masklinn wrote: post #8

Related: How Bad Is Your Colormap? (Or, Why People Hate Jet – and You Should Too): https://jakevdp.github.io/blog/2014/10/16/how-bad-is-your-co... Also related: seaborn (a helper library on top of matplotlib) has a special case dedicated to rejecting requests for using jet

Why is it called jet? Can't find any definition/abbreviation for it beside that it's called jet in MATLAB. https://www.mathworks.com/help/matlab/ref/jet.html

From some of what seem to be the matlab docs

> The jet colormap is associated with an astrophysical fluid jet simulation from the National Center for Supercomputer Applications. See the "Examples" section

http://matlab.izmiran.ru/help/techdoc/ref/colormap.html

Re: New Map Scale Is More Readable by People Who Are Color Blind

#27

Post by jfoldager »

driax wrote: post #21
DangerousPie wrote: post #18

Isn't this almost the same as the viridis palette that has been around for ages? https://cran.r-project.org/web/packages/viridis/vignettes/in...

I just skimmed the paper [1], and their conclusion starts: > We identified one colormap in particular to be optimal for viewing by those with or without CVD, which we name cividis (Figs 4 and 5), generated by optimizing the viridis colormap and selecting the J' linearization that maximizes the range of J'. We chose this map due to its wide range of colors, resulting from a wide range of J0 values while still changing…

I'm disappointed that they (in my opinion) managed to make a worse color scale. If you look at the CVD-Jet color bar you can see blocks that appears quite similar separated by too sharp transitions. This is a common problem in e.g. rainbow scales. They highlight them selves that yellow appears as highligt, yet the highest values get translated to black. How is black supposed to be interpreted as more luminescent/intense than yellow? It happens to be a color scale that makes the cells look good, but to me that is happenstance.

Re: New Map Scale Is More Readable by People Who Are Color Blind

#28

Post by nonane »

toomanybeersies wrote: post #13

I've been using Color Oracle [1] to simulate colour-blindness as part of my standard developer workflow recently. For such a common disability, it's shocking how little work most people put into ensuring accessibility for colour-blind people. [1] https://colororacle.org/

Thanks for the link. Is the macOS version working for you? I can't get it to work on High Sierra.

Re: New Map Scale Is More Readable by People Who Are Color Blind

#29

Post by nonane »

brianmcc wrote: post #25

I am always pleased to see annoucements and discussions on colour blindness. Forgive me for sharing again my writeup on this syndrome from my own experience, if you don't yourself have any such deficiencies you might find it interesting! https://mcconnellsoftware.github.io/colourblind-in-software-...

Thank you for the write up - this was good to read. Someone close to me was just diagnosed with color blindness and this was very helpful.

Re: New Map Scale Is More Readable by People Who Are Color Blind

#30

Post by raphlinus »

jfoldager wrote: post #27
driax wrote: post #21

Earlier quoted context omitted.

I just skimmed the paper [1], and their conclusion starts: > We identified one colormap in particular to be optimal for viewing by those with or without CVD, which we name cividis (Figs 4 and 5), generated by optimizing the viridis colormap and selecting the J' linearization that maximizes the range of J'. We chose this map due to its wide range of colors, resulting from a wide range of J0 values while still changing…

I'm disappointed that they (in my opinion) managed to make a worse color scale. If you look at the CVD-Jet color bar you can see blocks that appears quite similar separated by too sharp transitions. This is a common problem in e.g. rainbow scales. They highlight them selves that yellow appears as highligt, yet the highest values get translated to black. How is black supposed to be interpreted as more luminescent/inte…

CVD-Jet is not the new color scale, it's a simulation of what Jet looks like for certain colorblind users.

To my eyes, cividis (which is the new scale) is good by the numbers, and there's a strong argument it's more robust for colorblind users, but viridis looks better.

Post reply on HN