Difference between revisions of "Noise Reduction"
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The row uniformity is probably due to each ADC response. | The row uniformity is probably due to each ADC response. | ||
[[File:C1.png | 400px]] | [[File:C1.png | 400px]] | ||
Images generated by | |||
https://github.com/Matthias-Fauconneau/serenity/blob/master/field-correction.cc | |||
using http://files.apertus.org/AXIOM-Alpha/ darkframe-*.raw16.xz | |||
Revision as of 19:16, 28 February 2015
Record sensor temp alongside raw, apply different noise compensation depending on temp in post.
A Peltier can help build the profiles - by heating and cooling to a range of temperatures as needed.
Fixed Pattern Noise
General explanation: http://en.wikipedia.org/wiki/Fixed-pattern_noise
AXIOM Alpha measurements:
C0 + C1 * exposuretime
C0: Constant component of dark frame energy.
If all pixels are read in parallel, the column uniformity might come from temporal variation of thermal noise.
C1: Exposure dependant component of the dark energy.
The row uniformity is probably due to each ADC response.
Images generated by https://github.com/Matthias-Fauconneau/serenity/blob/master/field-correction.cc using http://files.apertus.org/AXIOM-Alpha/ darkframe-*.raw16.xz