BEAM Robotics- based on Nervous Network Technology

This is an experiment into colour visionfor [BEAM] robots. The basic BEAM vision system has remained the same. Would it not be interesting for a robot to change it's behaviour when it is exposed to different frequencies of light?

Colour Vision



Sometime ago in 1672, there was a dude who could not go outside to play cricket because of the Black Plague. He was very bored, and in attempts to alleviate his boredom( which leads to death btw), he carried out many experiments
and found new laws. And Calculus. This chap was called Newton, Sir Isaac Newton.
Newton discovered that by using a prism, white light could be split into many colours, which he thought were pretty. These colours were arranged in a precise spectrum, or array if you will, ranging from red, orange, yellow, green, blue, indigo and to violet. The order of these colours is constant and each one has its own unique signature...
Light can be defined as a wave, and as such has a property called frequency, f, and wavelength. These two properties (which are related) determine the colour of light we see. Different wavelengths of light have differing frequencies and will occupy certain areas of what is called the Electromagneitc Spectrum. The visible spectrum of light, which is an extremely small and finite region of the E.M. Spectrum, is between 700 and 400nm. This is shown in the diagram below:

Wavelengths of Light

Yeah, nice diagram huh? You can learn quite a bit from this diagram, if you look carefully one may notice that as we traverse the visible spectrum from violet through red the wavelengths, become longer. As the wavelengths increase, the frequency decreases.BTW, when you hear white light being thrown around, remember that white light simply is the combination of all wavelengths of light [in the visible spectrum]


  Colour Vision  


For the cases above, we can see that there is a defined spectral signature for those particular colours. Unfortunately, I kinda lied about every color having a specific spectra signature. Purple, for example, has no
single wavelength. It can be made by a combination of the wavelengths in both red and violet. Things degenerate even further with something like Brown. Brown is a rather unbelievably complex mixture of wavelengths
from at least four regions of the visible spectrum.
So, some colours are made up of other colours. Remember baby school: red + blue makes purple, Blue + yellow makes green....
I now invite the reader to go get themselves some finger paints and paper and start randomly mixing the primary colours to see what makes what. After you have finished, email me your results so I can make a table
of derived colours and their primary colour constituents.


In this section we must consider the colour of an object illuminated by white light.

When we perceive a coloured object, one must realise that that colour is produced because the object absorbs several selected wavelengths of light. The colour which we see is called the complementary colour. One can think of it as the object absorbs all the colours except that of its appearance, which are reflected.


White Light Incident on A coloured Object

If you look at this diagram we see that white light (which is comprised of the primary wavelengths) is incident upon
a blue object. The other frequencies of light are absorbed and only the Blue light is reflected. Thus, we see a
blue colour. This blue colour is the complementary colour, i.e, the remaining portion. This is true for all objects of all colours. Wouldn't it be interesting to remove the complementary colour from incident light on an object and see what colour it is?