Thread: Real cameras
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Bob Crantz
 
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Default Real cameras


"Martin Baxter" wrote in message

What the hell is "Chromolesence", and what's it got to do with black and
white images?


It's the humologuous transformation of a D1 type system conformal to a one
to one mapping of the gray scale. The drawback of this method is dynamic
range reduction but it does give remarkable contrast enhancement. It's very
much like the way the eye works. The eye has a timewise great long term
dynamic range and short term great sensitivity. The eye takes time to adjust
to nominal light intensity and then can discern fine levels of light
intensity. In the eye it's driven by chemical concentrations, in humologuous
gray scale transformations it's mathematical. The running average window is
much longer which establishes the baseline interjection recursive elements.
From this baseline, non logarithmic methods can be used to determine the
intensity granularity of the digitized black and white image. Linear
analysis gives much greater sensitivity than logrithmic analysis, plus phase
information is not lost. The reason it's called "chromolescence" is that the
original work was done for color images, which is a 7 vector space and then
reduced to black and white images which are a 4 vector space. Just search
Rabiner, Gold, Oppenhiem, Schafer and Tribolet.

Glory!