Re: Need help with digital alayzis

["Tor Lillqvist" <tml@xxxxxx>]

> Basically, what I need to do is to take a small part of a picture of
> an animal (a rock hyrax, lovely little things ^_^) and analyze how
> much of its fur color is based on red, brown, yellow etc.

I don't want to be blunt, but are you sure that makes any sense? Are
you researching how *humans* perceive these animals? Or how their prey
or predators perceive them?

If the latter, you should know that the whole concept of "colour" as
normally used is totally specific to the human visual system.
"colours" do not exist in the physical world, only in the human brain.

Other animals have very different perception of "colour" than us
humans. An animal whose fur to a human might look like it consists of
almost identical shades of brown, for instance, might to some other
animal look like it has very distinct stripes or whatever. Or the
other way around, an animal who looks very brightly patterned to us
humans, might to its predators look quite dull and blend in with its
surroundings well.

Digital photography (or colour film, for that matter) is designed to
capture colour information in a way that mimics human colour
perception. Taking a photograph is a very lossy process, as it throws
away the spectral information for the light arriving at each pixels
and instead stores just three values or "channels" of colour
information or each pixel. Analysing photographs for "redness",
"yellowness" etc is quite inappropriate if the intention is to relate
that to the colour vision of some non-human animals, as most of the
information has already been lost.

You need to read up on colour theory in general, and colour vision of
humans and the animals you are interested in. You can start with
wikipedia... http://en.wikipedia.org/wiki/Color_vision .

(All the above is just my humble opinion, of course.)

--tml


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