Matlab parula colormap

Development matplotlib-devel
1

Hi,

Matlab is now shipping with a new default colormap, named "parula" [1,2]. It is meant to overcome the many issues of the current default "jet". It seems that the RGB values of this new colormap are already onnline [3].

So my question is:
* is it worth adding this parula in the Matplotlib colormap collection ? (I think it is)
* is there any copyright issue with that ? (I have no idea how copyrightable a list of numbers is !)

(I'm not speeking of changing the *default* colormap since this is already discussed here https://github.com/matplotlib/matplotlib/issues/875)

best,
Pierre

1 http://blogs.mathworks.com/steve/2014/10/13/a-new-colormap-for-matlab-part-1-introduction/
2 http://blogs.mathworks.com/steve/2014/10/20/a-new-colormap-for-matlab-part-2-troubles-with-rainbows/
3 http://www.mathworks.com/matlabcentral/answers/158575-values-fo-colormap-parula

2

Hi,

Matlab is now shipping with a new default colormap, named "parula"
[1,2]. It is meant to overcome the many issues of the current default
"jet". It seems that the RGB values of this new colormap are already
onnline [3].

So my question is:
* is it worth adding this parula in the Matplotlib colormap collection ?
(I think it is)

Yes, *if* the answer to your next question allows it.

* is there any copyright issue with that ? (I have no idea how
copyrightable a list of numbers is !)

That's the big question: what is the IP status?

Eric

···

On 2014/10/20, 9:50 PM, Pierre Haessig wrote:

(I'm not speeking of changing the *default* colormap since this is
already discussed here Replace "jet" as the default colormap · Issue #875 · matplotlib/matplotlib · GitHub)

best,
Pierre

1
http://blogs.mathworks.com/steve/2014/10/13/a-new-colormap-for-matlab-part-1-introduction/
2
A New Colormap for MATLAB – Part 2 – Troubles with Rainbows » Steve on Image Processing with MATLAB - MATLAB & Simulink
3
http://www.mathworks.com/matlabcentral/answers/158575-values-fo-colormap-parula

------------------------------------------------------------------------------
Comprehensive Server Monitoring with Site24x7.
Monitor 10 servers for $9/Month.
Get alerted through email, SMS, voice calls or mobile push notifications.
Take corrective actions from your mobile device.
http://p.sf.net/sfu/Zoho
_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel@lists.sourceforge.net
matplotlib-devel List Signup and Options

3

The general rule is that copyright requires "creative expression".
This is a pretty marginal case at best, since that the colormap
appears to have been derived by solving an optimization problem, but
worst case we could always re-solve that optimization problem
ourselves. (I've played before with using CAM02-UCS to automatically
generate perceptually uniform colormaps - it's not terribly difficult
to do.)

-n

···

On Tue, Oct 21, 2014 at 8:50 AM, Pierre Haessig <pierre.haessig@...804...> wrote:

Hi,

Matlab is now shipping with a new default colormap, named "parula"
[1,2]. It is meant to overcome the many issues of the current default
"jet". It seems that the RGB values of this new colormap are already
onnline [3].

So my question is:
* is it worth adding this parula in the Matplotlib colormap collection ?
(I think it is)
* is there any copyright issue with that ? (I have no idea how
copyrightable a list of numbers is !)

--
Nathaniel J. Smith
Postdoctoral researcher - Informatics - University of Edinburgh

4

There are additional considerations, such as working well for the most common form of color-blindness, providing as much resolution as possible, and being aesthetically pleasing to most people.

Eric

···

On 2014/10/21, 6:27 AM, Nathaniel Smith wrote:

On Tue, Oct 21, 2014 at 8:50 AM, Pierre Haessig > <pierre.haessig@...804...> wrote:

Hi,

Matlab is now shipping with a new default colormap, named "parula"
[1,2]. It is meant to overcome the many issues of the current default
"jet". It seems that the RGB values of this new colormap are already
onnline [3].

So my question is:
* is it worth adding this parula in the Matplotlib colormap collection ?
(I think it is)
* is there any copyright issue with that ? (I have no idea how
copyrightable a list of numbers is !)

The general rule is that copyright requires "creative expression".
This is a pretty marginal case at best, since that the colormap
appears to have been derived by solving an optimization problem, but
worst case we could always re-solve that optimization problem
ourselves. (I've played before with using CAM02-UCS to automatically
generate perceptually uniform colormaps - it's not terribly difficult
to do.)

-n

5

Sure, but the first two of those are just extra constraints on the optimization.

Apparently they'll be making another blog post soon describing the
actual constraints they used.

···

On Tue, Oct 21, 2014 at 8:09 PM, Eric Firing <efiring@...229...> wrote:

On 2014/10/21, 6:27 AM, Nathaniel Smith wrote:

On Tue, Oct 21, 2014 at 8:50 AM, Pierre Haessig >> <pierre.haessig@...804...> wrote:

Hi,

Matlab is now shipping with a new default colormap, named "parula"
[1,2]. It is meant to overcome the many issues of the current default
"jet". It seems that the RGB values of this new colormap are already
onnline [3].

So my question is:
* is it worth adding this parula in the Matplotlib colormap collection ?
(I think it is)
* is there any copyright issue with that ? (I have no idea how
copyrightable a list of numbers is !)

The general rule is that copyright requires "creative expression".
This is a pretty marginal case at best, since that the colormap
appears to have been derived by solving an optimization problem, but
worst case we could always re-solve that optimization problem
ourselves. (I've played before with using CAM02-UCS to automatically
generate perceptually uniform colormaps - it's not terribly difficult
to do.)

There are additional considerations, such as working well for the most
common form of color-blindness, providing as much resolution as
possible, and being aesthetically pleasing to most people.

--
Nathaniel J. Smith
Postdoctoral researcher - Informatics - University of Edinburgh

6 
That's the big question: what is the IP status?

So Nathaniel and I asked, and the blog post author, Steve Eddins,

took the time to answer :

  Nathaniel and Pierre—Thanks for your interest in the new

parula colormap. * Parula is the end result of a creative design
effort over an extended period of time. I am pleased that you
find it so appealing. The colormap is, however, MathWorks
intellectual property, and it would not be appropriate or
acceptable to copy or re-use it in non-MathWorks plotting tools.*

  You might look at other sources of high-quality colormaps. I have

listed some in my technical paper on rainbow colormaps, published
earlier this month on mathworks.com.

So they claim the IP. Next question is: is this claim valid, and I'm

not a lawyer to answer it. I suspect that the answer could be
country specific. The only things that bother me in this IP claim, is the status of
all the plots produced with this colormap. They are in a sense a work, am I right ? So the question becomes : does Mathworks owns IP
right for all these plots ?!
Pierre

···

http://blogs.mathworks.com/steve/2014/10/20/a-new-colormap-for-matlab-part-2-troubles-with-rainbows/#comment-27702
derivative

7

Le 21/10/2014 10:09, Eric Firing a �crit :

That's the big question: what is the IP status?

So Nathaniel and I asked, and the blog post author, Steve Eddins, took
the time to answer :

    Nathaniel and Pierre�Thanks for your interest in the new parula
    colormap. /Parula is the end result of a creative design effort over
    an extended period of time. I am pleased that you find it so
    appealing. The colormap is, however, MathWorks intellectual
    property, and it would not be appropriate or acceptable to copy or
    re-use it in non-MathWorks plotting tools./

    You might look at other sources of high-quality colormaps. I have
    listed some in my technical paper on rainbow colormaps, published
    earlier this month on mathworks.com.

A New Colormap for MATLAB – Part 2 – Troubles with Rainbows » Steve on Image Processing with MATLAB - MATLAB & Simulink

So they claim the IP. Next question is: is this claim valid, and I'm not
a lawyer to answer it. I suspect that the answer could be country specific.

Regardless, we should respect their claim. I agree with the basic idea: it was the result of a creative process, and they choose to keep that as proprietary IP. Therefore mpl will not include a clone of this color map. If a user decides to make and use a clone, that's their business, not ours. We shouldn't encourage it.

The only things that bother me in this IP claim, is the status of all
the plots produced with this colormap. They are in a sense a
/derivative/ work, am I right ? So the question becomes : does Mathworks
owns IP right for all these plots ?!

Perhaps they could claim copyright infringement; but from the mpl perspective, I don't think it matters. The question will only arise in practice if a user makes a plot with a clone of parula, and Mathworks chooses to turn it into a legal issue. I think it is unlikely this will happen; but if and when it does, I don't think mpl will be involved. We will not be supplying the colormap or in any way encouraging or condoning its use in mpl, unless and until Mathworks releases it.

Eric

···

On 2014/10/28, 10:30 PM, Pierre Haessig wrote:

Pierre

------------------------------------------------------------------------------

_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel@lists.sourceforge.net
matplotlib-devel List Signup and Options