release strategy and the color revolution

Development matplotlib-devel
21

Well, since we are thinking of it… What about prettyplotlib’s style? I am not sure I want to completely steal either project’s style as it is their own look-n-feel (and there are some aspects of their styles I don’t quite like, but I am something of a luddite…). But I would certainly be receptive to addressing whatever egregious appearance faux pas we may have. Perhaps the owners of those projects could provide use feedback on what they might consider their “short-list” for things they would fix in matplotlib?

···

On Sat, Feb 28, 2015 at 5:50 PM, Todd <toddrjen@…149…> wrote:

On Feb 19, 2015 1:39 AM, “Nathaniel Smith” <njs@…503…> wrote:

On Feb 16, 2015 3:39 PM, “Eric Firing” <efiring@…229…> wrote:

On 2015/02/16 1:29 PM, Michael Waskom wrote:

Nathaniel’s January 9 message in that thread (can’t figure out how to
link to it in the archives) had a suggestion that I thought was very
promising, to do something similar to Parula but rotate around the hue
circle the other direction so that the hues would go blue - purple - red

Certainly it can be considered–but we have to have a real implementation.

While I hate to promise vaporware, I actually was planning to have a
go at implementing such a colormap in the next few weeks, based on
optimizing the same set of parameters that viscm visualizes… FWIW.

Are we planning to make other default appearance changes at the same
time? The idea of changing the color cycle and/or dot-dash cycle has
already come up in this thread, and this earlier thread proposed
several more good ideas [1]:
http://thread.gmane.org/gmane.comp.python.matplotlib.devel/13128/focus=13166

If the goal is still to put all the appearance-related changes in a single release (to simplify changes to downstream unit tests), but nobody has stepped up to make changes except to the colors, might it be possible to just adopt the default seaborn style (except for colors, of course)? If anybody is strongly motivated to make changes they can, but if nobody does there would still be a good, modern, pleasant-looking style used by default.

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22

Hi everyone,
As someone working with images, I think for displaying images you want a
colormap that spans as much as possible of the luminance range. The colormap
suggested by Michael Waskom would be quite perfect as-is. (recap: middle
colormap here:
http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png)

I understand the concern that a colormap should be able to display things on
dark and light backgrounds, but this applies only to plots, not to images.
Tom Caswell emphasised the distinction between colormaps for continuous
variables and color cycles for categorical variables. There should also be a
distinction between image display and plotting. For image display, please
consider using a colormap with a wide luminance range.

Thanks!

···

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23

Hi,

···

Le 01/03/2015 23:27, jni a écrit :

As someone working with images, I think for displaying images you want a
colormap that spans as much as possible of the luminance range. The colormap
suggested by Michael Waskom would be quite perfect as-is. (recap: middle
colormap here:
http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png)

Thanks for this feedback. Could you please elaborate a bit on this
usecase. I was thinking, naively, that when plotting a grayscale image,
one would simply used a gray colormap. Do you have some examples to
illustrate what kind of results you are expecting ?

best,
Pierre

24

Hi Pierre,

···

Could you please elaborate a bit on this

usecase. I was thinking, naively, that when plotting a grayscale image,

one would simply used a gray colormap.

Using a colormap with hue and saturation gives you better contrast than pure grayscale. For natural images, that is, photographs of human-scale objects, indeed grayscale is a good choice, because that is how we are used to looking at those images. But for looking at physical quantities, for example, using a colormap with hue and saturation as well as lightness is useful. Here are some examples:

http://www.gnuplotting.org/color-maps-from-colorbrewer/

https://www.mrao.cam.ac.uk/~dag/CUBEHELIX/

See also a “boundary probability map” for a natural image here (panel B, top right):

http://www.frontiersin.org/files/Articles/74212/fninf-08-00034-r2/image_m/fninf-08-00034-g001.jpg

Having the colormap makes it easier to place the intermediate levels of the probability map.

Again, restricting the lightness range for these maps would be problematic, to say the least.

Juan.

25

I have opened a PR to document this discussion. It is meant to provide a permanent record of the thought process leading up to color map and to serve as a tool in making the finial decision.

https://github.com/matplotlib/matplotlib/pull/4238

···

Could you please elaborate a bit on this

usecase. I was thinking, naively, that when plotting a grayscale image,

one would simply used a gray colormap.

Using a colormap with hue and saturation gives you better contrast than pure grayscale. For natural images, that is, photographs of human-scale objects, indeed grayscale is a good choice, because that is how we are used to looking at those images. But for looking at physical quantities, for example, using a colormap with hue and saturation as well as lightness is useful. Here are some examples:

http://www.gnuplotting.org/color-maps-from-colorbrewer/

https://www.mrao.cam.ac.uk/~dag/CUBEHELIX/

See also a “boundary probability map” for a natural image here (panel B, top right):

http://www.frontiersin.org/files/Articles/74212/fninf-08-00034-r2/image_m/fninf-08-00034-g001.jpg

Having the colormap makes it easier to place the intermediate levels of the probability map.

Again, restricting the lightness range for these maps would be problematic, to say the least.

Juan.

26

While it's taking longer than hoped, just to reassure you that this
isn't total vaporware, here's a screenshot from the colormap designer
that Stéfan van der Walt and I have been working on... still needs
fine-tuning (which at this point probably won't happen until after I
get back from PyCon), but we like what we're seeing so far :slight_smile:

The colormap shown has, by construction, perfect lightness linearity
and perfect perceptual uniformity, according to the better-than-CIELAB
model used by the viscm tool I linked upthread.

colormap-designer-teaser.png
colormap-designer-teaser.png1189×866 40.3 KB

···

On Mon, Feb 23, 2015 at 10:46 AM, Eric Firing <efiring@...229...> wrote:

On 2015/02/18 2:39 PM, Nathaniel Smith wrote:

On Feb 16, 2015 3:39 PM, "Eric Firing" <efiring@...229...> wrote:

On 2015/02/16 1:29 PM, Michael Waskom wrote:

Nathaniel's January 9 message in that thread (can't figure out how to
link to it in the archives) had a suggestion that I thought was very
promising, to do something similar to Parula but rotate around the hue
circle the other direction so that the hues would go blue - purple - red
- yellow. I don't think we've seen an example of exactly what it would
look like, but I reckon it would be similar to the middle colormap here

http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png
(from the elegant figures block series linked above), which I've always
found quite attractive.

Certainly it can be considered--but we have to have a real
implementation.

While I hate to promise vaporware, I actually was planning to have a
go at implementing such a colormap in the next few weeks, based on
optimizing the same set of parameters that viscm visualizes... FWIW.

It might be worth quite a bit--and the sooner, the better.

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

27

Thanks for the update, and the progress. The example colormap looks promising as a viable alternative. It appears to have good contrast. How well does this type of map work with the colorblindness filters?

Eric

···

On 2015/04/04 9:20 PM, Nathaniel Smith wrote:

While it's taking longer than hoped, just to reassure you that this
isn't total vaporware, here's a screenshot from the colormap designer
that Stéfan van der Walt and I have been working on... still needs
fine-tuning (which at this point probably won't happen until after I
get back from PyCon), but we like what we're seeing so far :slight_smile:

The colormap shown has, by construction, perfect lightness linearity
and perfect perceptual uniformity, according to the better-than-CIELAB
model used by the viscm tool I linked upthread.

28

<3 <3 <3 Love the prototype colormap!!!

···

On Sun, Apr 5, 2015 at 5:21 PM, Nathaniel Smith <njs@…503…> wrote:

On Mon, Feb 23, 2015 at 10:46 AM, Eric Firing <efiring@…229…> wrote:

On 2015/02/18 2:39 PM, Nathaniel Smith wrote:

On Feb 16, 2015 3:39 PM, “Eric Firing” <efiring@…229…> wrote:

On 2015/02/16 1:29 PM, Michael Waskom wrote:

Nathaniel’s January 9 message in that thread (can’t figure out how to

link to it in the archives) had a suggestion that I thought was very

promising, to do something similar to Parula but rotate around the hue

circle the other direction so that the hues would go blue - purple - red

  • yellow. I don’t think we’ve seen an example of exactly what it would

look like, but I reckon it would be similar to the middle colormap here

http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png

(from the elegant figures block series linked above), which I’ve always

found quite attractive.

Certainly it can be considered–but we have to have a real

implementation.

While I hate to promise vaporware, I actually was planning to have a

go at implementing such a colormap in the next few weeks, based on

optimizing the same set of parameters that viscm visualizes… FWIW.

It might be worth quite a bit–and the sooner, the better.

While it’s taking longer than hoped, just to reassure you that this

isn’t total vaporware, here’s a screenshot from the colormap designer

that Stéfan van der Walt and I have been working on… still needs

fine-tuning (which at this point probably won’t happen until after I

get back from PyCon), but we like what we’re seeing so far :slight_smile:

The colormap shown has, by construction, perfect lightness linearity

and perfect perceptual uniformity, according to the better-than-CIELAB

model used by the viscm tool I linked upthread.

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

<colormap-designer-teaser.png>------------------------------------------------------------------------------

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<colormap-designer-teaser.png>

29

Blue/yellow contrast is preserved with the common types of
colorblindness, so it should become a smooth ramp of blue ->
(reddish/greyish, depending on details/severity of color deficiency)
-> yellow. And the luminance remains linear. So it's definitely not a
disaster.

Beyond that I'm not entirely sure how to numerically quantify
perceptual uniformity for colorblind users -- we could use the
sRGB->sRGB formulas for simulating colorblindness for non-colorblind
viewers and then use the regular non-colorblind uniformity estimates,
but I have no idea how accurate that would be... my guess though is
that the way that colormaps is designed ATM it will have somewhat
faster hue shifts in the lower (blue) region than the upper (yellow)
region, and fastest in the middle, though this effect shouldn't be
huge (and to some extent is inevitable with any map that's both
colorful and perceptually uniform for non-colorblind users). Thinking
through these details is one of the things I had in mind when I
mentioned "fine tuning" above though :-).

We'd welcome any feedback from readers with non-simulated color deficiency!

-n

···

On Sun, Apr 5, 2015 at 12:46 AM, Eric Firing <efiring@...229...> wrote:

On 2015/04/04 9:20 PM, Nathaniel Smith wrote:

While it's taking longer than hoped, just to reassure you that this
isn't total vaporware, here's a screenshot from the colormap designer
that Stéfan van der Walt and I have been working on... still needs
fine-tuning (which at this point probably won't happen until after I
get back from PyCon), but we like what we're seeing so far :slight_smile:

The colormap shown has, by construction, perfect lightness linearity
and perfect perceptual uniformity, according to the better-than-CIELAB
model used by the viscm tool I linked upthread.

Thanks for the update, and the progress. The example colormap looks
promising as a viable alternative. It appears to have good contrast. How
well does this type of map work with the colorblindness filters?

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

30

That is nice. The blue is a bit heavy, but that might be my display. Now, how should we order it by default? I am used to thinking of blues as lower values, and reds as higher. The yellow at the end throws me off a bit, because I would think of it as a “weaker” color. Maybe if it was more gold-like?

We should also start thinking of a snazzy name. BlRdYe probably won’t cut it.

Ben Root

···

On Apr 5, 2015 3:21 AM, “Nathaniel Smith” <njs@…503…> wrote:

On Mon, Feb 23, 2015 at 10:46 AM, Eric Firing <efiring@…865…9…> wrote:

On 2015/02/18 2:39 PM, Nathaniel Smith wrote:

On Feb 16, 2015 3:39 PM, “Eric Firing” <efiring@…229…> wrote:

On 2015/02/16 1:29 PM, Michael Waskom wrote:

Nathaniel’s January 9 message in that thread (can’t figure out how to

link to it in the archives) had a suggestion that I thought was very

promising, to do something similar to Parula but rotate around the hue

circle the other direction so that the hues would go blue - purple - red

  • yellow. I don’t think we’ve seen an example of exactly what it would

look like, but I reckon it would be similar to the middle colormap here

http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png

(from the elegant figures block series linked above), which I’ve always

found quite attractive.

Certainly it can be considered–but we have to have a real

implementation.

While I hate to promise vaporware, I actually was planning to have a

go at implementing such a colormap in the next few weeks, based on

optimizing the same set of parameters that viscm visualizes… FWIW.

It might be worth quite a bit–and the sooner, the better.

While it’s taking longer than hoped, just to reassure you that this

isn’t total vaporware, here’s a screenshot from the colormap designer

that Stéfan van der Walt and I have been working on… still needs

fine-tuning (which at this point probably won’t happen until after I

get back from PyCon), but we like what we’re seeing so far :slight_smile:

The colormap shown has, by construction, perfect lightness linearity

and perfect perceptual uniformity, according to the better-than-CIELAB

model used by the viscm tool I linked upthread.

–

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

Dive into the World of Parallel Programming The Go Parallel Website, sponsored

by Intel and developed in partnership with Slashdot Media, is your hub for all

things parallel software development, from weekly thought leadership blogs to

news, videos, case studies, tutorials and more. Take a look and join the

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31

How about “pythonic sunset” ?

···

On Sun, Apr 5, 2015 at 2:01 PM Benjamin Root <ben.root@…553…> wrote:

That is nice. The blue is a bit heavy, but that might be my display. Now, how should we order it by default? I am used to thinking of blues as lower values, and reds as higher. The yellow at the end throws me off a bit, because I would think of it as a “weaker” color. Maybe if it was more gold-like?

We should also start thinking of a snazzy name. BlRdYe probably won’t cut it.

Ben Root

On Apr 5, 2015 3:21 AM, “Nathaniel Smith” <njs@…503…> wrote:

On Mon, Feb 23, 2015 at 10:46 AM, Eric Firing <efiring@…229…> wrote:

On 2015/02/18 2:39 PM, Nathaniel Smith wrote:

On Feb 16, 2015 3:39 PM, “Eric Firing” <efiring@…229…> wrote:

On 2015/02/16 1:29 PM, Michael Waskom wrote:

Nathaniel’s January 9 message in that thread (can’t figure out how to

link to it in the archives) had a suggestion that I thought was very

promising, to do something similar to Parula but rotate around the hue

circle the other direction so that the hues would go blue - purple - red

  • yellow. I don’t think we’ve seen an example of exactly what it would

look like, but I reckon it would be similar to the middle colormap here

http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png

(from the elegant figures block series linked above), which I’ve always

found quite attractive.

Certainly it can be considered–but we have to have a real

implementation.

While I hate to promise vaporware, I actually was planning to have a

go at implementing such a colormap in the next few weeks, based on

optimizing the same set of parameters that viscm visualizes… FWIW.

It might be worth quite a bit–and the sooner, the better.

While it’s taking longer than hoped, just to reassure you that this

isn’t total vaporware, here’s a screenshot from the colormap designer

that Stéfan van der Walt and I have been working on… still needs

fine-tuning (which at this point probably won’t happen until after I

get back from PyCon), but we like what we’re seeing so far :slight_smile:

The colormap shown has, by construction, perfect lightness linearity

and perfect perceptual uniformity, according to the better-than-CIELAB

model used by the viscm tool I linked upthread.

–

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

Dive into the World of Parallel Programming The Go Parallel Website, sponsored

by Intel and developed in partnership with Slashdot Media, is your hub for all

things parallel software development, from weekly thought leadership blogs to

news, videos, case studies, tutorials and more. Take a look and join the

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32

I like it, but perhaps we should condense it to one word for ease of
typing, how about “Redgauntlet”?� It kind of feels appropriate (for
those who need an explanation of why, see ).
On the colormap itself, it looks good apart from the fade into blue,
my eyes on this laptop monitor see a sharp gradient around 0.2
compared with the more gradual gradient at the other end.� Also I
see constant colour between 0 and 0.1, and between 0.9 and 1, with
less change between 0.8 to 0.9 then 0.1 and 0.2.� Not sure if one
causes an optical illusion in the other or not.
Finally a bit confused as to what all the lines mean, any chance of
some annotation?� Also I would find it helpful to see a version
without the big red line and what it looks like in practice (see the
doc for the test script).
Best,
OceanWolf

···

https://www.youtube.com/watch?v=_guKhYVr5vA

  On 05/04/15 23:18, Olga Botvinnik

wrote:

How about “pythonic sunset” ?

    On Sun, Apr 5, 2015 at 2:01 PM Benjamin

Root <ben.root@…553… >
wrote:

        That is nice. The blue is a bit heavy, but that

might be my display. Now, how should we order it by default?
I am used to thinking of blues as lower values, and reds as
higher. The yellow at the end throws me off a bit, because I
would think of it as a “weaker” color. Maybe if it was more
gold-like?

        We should also start thinking of a snazzy name.

BlRdYe probably won’t cut it.

Ben Root

        On Apr 5, 2015 3:21 AM, "Nathaniel

Smith" <njs@…503… >
wrote:

          On Mon,

Feb 23, 2015 at 10:46 AM, Eric Firing <efiring@…229…> wrote:

          > On 2015/02/18 2:39 PM, Nathaniel Smith wrote:

          >>

          >> On Feb 16, 2015 3:39 PM, "Eric Firing" <efiring@...229...> wrote:

          >>>

          >>>

          >>> On 2015/02/16 1:29 PM, Michael Waskom wrote:

          >>>

          >>>> Nathaniel's January 9 message in that

thread (can’t figure out how to

          >>>> link to it in the archives) had a

suggestion that I thought was very

          >>>> promising, to do something similar to

Parula but rotate around the hue

          >>>> circle the other direction so that the

hues would go blue - purple - red

          >>>> - yellow. I don't think we've seen an

example of exactly what it would

          >>>> look like, but I reckon it would be

similar to the middle colormap here

          >>>>

          >>>> [http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png](http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png)

          >>>> (from the elegant figures block series

linked above), which I’ve always

          >>>> found quite attractive.

          >>>

          >>>

          >>> Certainly it can be considered--but we have

to have a real

          >>> implementation.

          >>

          >>

          >> While I hate to promise vaporware, I actually was

planning to have a

          >> go at implementing such a colormap in the next

few weeks, based on

          >> optimizing the same set of parameters that viscm

visualizes… FWIW.

          >

          >

          > It might be worth quite a bit--and the sooner, the

better.

          While it's taking longer than hoped, just to reassure you

that this

          isn't total vaporware, here's a screenshot from the

colormap designer

          that St�fan van der Walt and I have been working on...

still needs

          fine-tuning (which at this point probably won't happen

until after I

          get back from PyCon), but we like what we're seeing so far

:slight_smile:

          The colormap shown has, by construction, perfect lightness

linearity

          and perfect perceptual uniformity, according to the

better-than-CIELAB

          model used by the viscm tool I linked upthread.



          --

          Nathaniel J. Smith -- [http://vorpus.org](http://vorpus.org)

          Dive into the World of Parallel Programming The Go

Parallel Website, sponsored

          by Intel and developed in partnership with Slashdot Media,

is your hub for all

          things parallel software development, from weekly thought

leadership blogs to

          news, videos, case studies, tutorials and more. Take a

look and join the

          conversation now. [http://goparallel.sourceforge.net/](http://goparallel.sourceforge.net/)

          _______________________________________________

          Matplotlib-devel mailing list

          Matplotlib-devel@lists.sourceforge.net

          [https://lists.sourceforge.net/lists/listinfo/matplotlib-devel](https://lists.sourceforge.net/lists/listinfo/matplotlib-devel)

      Dive into the World of Parallel Programming The Go Parallel

Website, sponsored

      by Intel and developed in partnership with Slashdot Media, is

your hub for all

      things parallel software development, from weekly thought

leadership blogs to

      news, videos, case studies, tutorials and more. Take a look

and join the

      conversation now. [http://goparallel.sourceforge.net/](http://goparallel.sourceforge.net/)_______________________________________________

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------------------------------------------------------------------------------
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_______________________________________________
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33

I checked with my red-green color-blind colleague, Niklas Schneider, and his evaluation is attached.

Eric

Attached Message (11 KB)

···

On 2015/04/04 10:10 PM, Nathaniel Smith wrote:

We'd welcome any feedback from readers with non-simulated color deficiency!

34

Just wondering whether anyone has suggested checking candidate colormaps against typical printer color gamuts?

···

On 6 Apr 2015 1:11 pm, “Eric Firing” <efiring@…229…> wrote:

On 2015/04/04 10:10 PM, Nathaniel Smith wrote:

We’d welcome any feedback from readers with non-simulated color deficiency!

I checked with my red-green color-blind colleague, Niklas Schneider, and his evaluation is attached.

Eric

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35

How would you go about doing this in practice? Is it even possible to choose a subset of sRGB space and have printers take advantage of that when doing gamut mapping? (I guess I always assumed that printer gamut mapping applied to an RGB image would map all of RGB into their gamut, so there would be no advantage to restricting oneself go a subspace. But maybe I’m wrong – color management is pretty fancy these days.)

-n

···

On Apr 5, 2015 8:29 PM, “gary ruben” <gary.ruben@…149…> wrote:

Just wondering whether anyone has suggested checking candidate colormaps against typical printer color gamuts?

36

“sunset” has a connotation of things ending. Howabout “sunrise”?

···

On Sun, Apr 5, 2015 at 5:18 PM, Olga Botvinnik <obotvinn@…170…> wrote:

How about “pythonic sunset” ?

On Sun, Apr 5, 2015 at 2:01 PM Benjamin Root <ben.root@…553…> wrote:

That is nice. The blue is a bit heavy, but that might be my display. Now, how should we order it by default? I am used to thinking of blues as lower values, and reds as higher. The yellow at the end throws me off a bit, because I would think of it as a “weaker” color. Maybe if it was more gold-like?

We should also start thinking of a snazzy name. BlRdYe probably won’t cut it.

Ben Root

On Apr 5, 2015 3:21 AM, “Nathaniel Smith” <njs@…503…> wrote:

On Mon, Feb 23, 2015 at 10:46 AM, Eric Firing <efiring@…229…> wrote:

On 2015/02/18 2:39 PM, Nathaniel Smith wrote:

On Feb 16, 2015 3:39 PM, “Eric Firing” <efiring@…229…> wrote:

On 2015/02/16 1:29 PM, Michael Waskom wrote:

Nathaniel’s January 9 message in that thread (can’t figure out how to

link to it in the archives) had a suggestion that I thought was very

promising, to do something similar to Parula but rotate around the hue

circle the other direction so that the hues would go blue - purple - red

  • yellow. I don’t think we’ve seen an example of exactly what it would

look like, but I reckon it would be similar to the middle colormap here

http://earthobservatory.nasa.gov/blogs/elegantfigures/files/2013/08/three_perceptual_palettes_618.png

(from the elegant figures block series linked above), which I’ve always

found quite attractive.

Certainly it can be considered–but we have to have a real

implementation.

While I hate to promise vaporware, I actually was planning to have a

go at implementing such a colormap in the next few weeks, based on

optimizing the same set of parameters that viscm visualizes… FWIW.

It might be worth quite a bit–and the sooner, the better.

While it’s taking longer than hoped, just to reassure you that this

isn’t total vaporware, here’s a screenshot from the colormap designer

that Stéfan van der Walt and I have been working on… still needs

fine-tuning (which at this point probably won’t happen until after I

get back from PyCon), but we like what we’re seeing so far :slight_smile:

The colormap shown has, by construction, perfect lightness linearity

and perfect perceptual uniformity, according to the better-than-CIELAB

model used by the viscm tool I linked upthread.

–

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

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37

I guess you could just load some test patterns into any commercial software graphics or design package that supports color gamut alarms, and try some typical printer settings to make sure that the candidate color maps aren’t excessively blowing the boundaries. I’m not advocating that the default color map needs to be perfectly reproducible in print, but it might be worth sanity checking this; it might mean avoiding bright greens and yellows for example. I see that PIL/pillow contains littlecms support and I see its ImageCms.py
file contains a GAMUTCHECK flag, so it might be possible to use that, along with some common icc profiles to automate the checking, or build it into an optimiser as a constraint.

···

On 6 April 2015 at 15:57, Nathaniel Smith <njs@…503…> wrote:

On Apr 5, 2015 8:29 PM, “gary ruben” <gary.ruben@…149…> wrote:

Just wondering whether anyone has suggested checking candidate colormaps against typical printer color gamuts?

How would you go about doing this in practice? Is it even possible to choose a subset of sRGB space and have printers take advantage of that when doing gamut mapping? (I guess I always assumed that printer gamut mapping applied to an RGB image would map all of RGB into their gamut, so there would be no advantage to restricting oneself go a subspace. But maybe I’m wrong – color management is pretty fancy these days.)

-n