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Old 29-03-2010, 02:26 AM
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mjc (Mark)
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Join Date: Mar 2010
Location: Dublin, Ireland
Posts: 52
Dietmar

Thankyou for your post - in fact it was your post that encouraged me to bite the bullet and join this forum today in recognition of the quality of the forum (whenever I've been searching for answers I often find myself at an iceinspace thread).

I enjoyed the post. First I'd like to point out that in the text immediately above the graph you accidently (I think) swap the terms cones and rods.

I think its a wonderful article that you should develop it further over time.

Material I'd like to suggest for inclusion is the relationship between the physiology of the eye and the decision by Bayer to double-up the green sensor in the Bayer matrix - which I seem to recall was to match the greater acuity of the eye in green.

The circular ring of rods is new to me and is quite thought provoking.
I am trying to work out what benefit the ring structure would have and can only (weakly) associate it with the saccades (rapid movement movement) of the eye which (at least to some degree) allows it to identify boundaries and thus achieve data-compression for transmission to the brain over a less dense nerve bundle which you describe.

The eye only has a small aperture - its diffraction limited resolution has to be poor. It would be enlightening to find what the eye's "pixel scale" (at fovea and elsewhere) is and to determine if the saccades contributed to dithering/resampling and whether there are techniques that we can learn and transfer to our astroimaging process.

You refer to true colour and false colour, may I also introduce the concept of "representative colour". This is where we match the longest wavelength image to red, the shortest wavelength image to blue, and whatever we have in the middle to green. We are true to the order of the wavelengths but they need not be the familiar RGB that the eye can see (eg we can use IR or even radio for red and UV for Blue).

I gleamed that snippet from the following which is worth a read in general:
http://www.spacetelescope.org/projec...or/improc.html

Mark
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