Posted by
Gabriel Landini on
Dec 20, 2010; 11:14am
URL: http://imagej.273.s1.nabble.com/Re-Assessing-bird-colouration-tp3686131p3686133.html
Hi Bob thanks for the follow up.
My argument was that one cannot, with only 3 sensors, for example,
differentiate whether something is truly orange or the sum of certain green
and red (and other) wavelengths. So it is possible that the plumage across
species is in reality very different, but the colour perceived might be the
same. One wants to avoid this:
http://en.wikipedia.org/wiki/Metamerism_(color)
And it might be very tricky if the data is gathered as RGB in the first place.
Of course, I agree that to differentiate a green parrot [*] from a white swan,
one might not need spectral analysis in the first place. My suggestion is that
if there is specific equipment to do this correctly, I see no point in trying
to do it otherwise.
Liaising with a physics, optics or engineering department might give the
opportunity to use a spectrometer or a tunable filter and resolve this in the
best possible way. They might be keen in collaborating on a project like this.
But in any case, to further address the photo posted, one needs a calibrated
image shot with a colour chart and use something like this:
http://imagejdocu.tudor.lu/doku.php?id=plugin:color:chart_white_balance:startI hope it helps.
Cheers
Gabriel
(* either dead or not, :-) in case there are any Monty Python fans)