Difference between revisions of "Noise Reduction"
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C0: Constant component of dark frame energy. | 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. | If all pixels are read in parallel, the column uniformity might come from temporal variation of thermal noise. | ||
[[File:C0.png | 400px]] | [[File:C0.png | 400px]] | ||
C1: Exposure dependant component of the dark energy. | C1: Exposure dependant component of the dark energy. | ||
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 | Images generated by | ||
https://github.com/Matthias-Fauconneau/serenity/blob/master/field-correction.cc | https://github.com/Matthias-Fauconneau/serenity/blob/master/field-correction.cc | ||
using http://files.apertus.org/AXIOM-Alpha/ darkframe-*.raw16.xz | using http://files.apertus.org/AXIOM-Alpha/darkframe-*.raw16.xz | ||
Revision as of 19:33, 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