RFC: candidates for a new default colormap

I think the very dark tones in Options A and B would make it harder to
add annotations on top, so C and D are better for that. Between C and
D I find that C looks slightly more "energetic", D is too rather calm
though nice. When used in talks, you can see the green laser pointer
better on top of C.

-Alexander

···

On 3 June 2015 at 11:46, Nathaniel Smith <njs@...503...> wrote:

Hi all,

As was hinted at in a previous thread, Stéfan van der Walt and I have
been using some Fancy Color Technology to attempt to design a new
colormap intended to become matplotlib's new default. (Down with jet!)

Unfortunately, while our Fancy Color Technology includes a
computational model of perceptual distance, it does not include a
computational model of aesthetics. So this is where you come in.

We've put up three reasonable candidates at:
    https://bids.github.io/colormap/
(along with some well-known colormaps for comparison), and we'd like
your feedback.

They are all optimal on all of the objective criteria we know how to
measure. What we need judgements on is which one you like best, both
aesthetically and as a way of visualizing data. (There are some sample
plots to look at there, plus you can download them and play with them
on your own data if you want.)

We especially value input from anyone with anomalous color vision.
There are some simulations there, but computational models are
inherently limited here. (It's difficult to ask someone with
colorblindness "does this look to you, the same way this other picture
looks to me?")

-n

--
Nathaniel J. Smith -- http://vorpus.org

------------------------------------------------------------------------------
_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-devel

And perhaps a red laser pointer better on top of D?

···

On 2015/06/04 9:52 AM, Alexander Heger wrote:

When used in talks, you can see the green laser pointer
better on top of C.

… unless you have red-green colorblindness. I abhor using laser pointers during talks and instead use descriptive text such as “upper-left” or “in the middle”. Also helps when only the slides and the audio is being recorded.

As for option D, my only apprehension for it is on the blue (purple?) end of the scale. I can’t really perceive any changes on that end and it just seems like a solid color to me. Does it seem that way to anybody else? Maybe shift the curve a bit to start a little more into the greens and have more yellow/orange?

As for branding, while it isn’t the same as Matlab’s Parula, it does look similar. That may or may not be a concern.

Ben Root

···

On Thu, Jun 4, 2015 at 4:13 PM, Eric Firing <efiring@…706…29…> wrote:

On 2015/06/04 9:52 AM, Alexander Heger wrote:

When used in talks, you can see the green laser pointer

better on top of C.

And perhaps a red laser pointer better on top of D?



Matplotlib-devel mailing list

Matplotlib-devel@lists.sourceforge.net

https://lists.sourceforge.net/lists/listinfo/matplotlib-devel

This is useful feedback, but FWIW it looks fine here... so my first
guess is that this is due to variation between individual monitors.
While the Fancy Color Math we're using is definitely not perfect, it
does represent basically everything anyone knows about how color
works. The biggest limitation is that at the end of the day we have to
write down the colormap using RGB values, and you can send the exact
same RGB values to two different monitors and get different colors. So
the only thing we can do is to target sRGB, which has two virtues:
it's designed to be an inexact but reasonable approximation to what
most hardware does if you use it in a naive way; and, it's also what's
expected by more sophisticated setups -- like OSes and applications
that are color-management-aware, and ideally have access to calibrated
models of specific monitors / printers / whatever.

Over time this will hopefully improve as software and hardware are
upgraded, and more workflows will become "sophisticated". But until
then there's not much to do besides target sRGB and cross our fingers.
Unless anyone has access to some data on how popular consumer hardware
systematically deviates from sRGB... designing the perfect colormap
for "the monitor sitting on Benjamin Root's desk with its current
software drivers" may or may not help for anyone else :-).

Lacking real data like this, the best we can hope for is to try and
avoid any colormap that lots of people report causing specific
problems on the hardware they have access to (which is why I was
asking about projectors in particular upthread).

TL;DR: please do report such issues, but IMO these reports are only
really useful if lots of people report the same thing, or if it causes
many people to prefer one colormap to another; unfortunately it's not
very useful for tweaking small details.

-n

···

On Thu, Jun 4, 2015 at 3:32 PM, Benjamin Root <ben.root@...553...> wrote:

As for option D, my only apprehension for it is on the blue (purple?) end of
the scale. I can't really perceive any changes on that end and it just seems
like a solid color to me. Does it seem that way to anybody else? Maybe shift
the curve a bit to start a little more into the greens and have more
yellow/orange?

--
Nathaniel J. Smith -- http://vorpus.org