🚀 go-pugleaf

Hello everybody !

I am looking for an algorithm to build a color palette automatically in the
following conditions :

- I have 4096 colors (R:0..15, G:0..15, B:0..15) and I can display 16 of them
simultaneously on my screen.
- The resolution of the screen is high enough to enable color mixing :
if I have two colors, X and Y, a pattern like  XY
                                               YX looks like an intermediate
color.

So, I should theorically be able to get a 128 colors display with this method.

THE PROBLEM : not all the combinations can be used if I want to build a
continuous palette (say black->blue->green->yellow->red->white)
(in this case for example : black+white -> grey... where can I place it in
the palette ??)

(I need a continuous palette without having colors similar at
different locations in the palette (like for example : black->blue->red->blue->...), since it is used to display the
radioactivity level on IRM or Gamma-Angiography images, so it should not
be confusing !!)

So, my questions are :

* given the 16 primary colors, is there an algorithm to make the longest
continuous palette using the 128 colors available through that mixing method ?
* is there an algorithm to optimize the choice of the 16 primary colors,
in order to get the longest palette possible ?


(subsidiary question (to differenciate the ex-aequo winners) : in another
graphic mode, I can display all the 4096 colors simultaneously. What is
the longest linear palette I can make ??)

THANKS A LOT IN ADVANCE FOR ANY IDEA !
            Laurent.

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Laurent ITTI - Ecole Nationale Superieure des Telecommunications de Paris
itti@enst.enst.fr