Skottbrus
Skottbrus är en typ av elektroniskt brus som kommer ifrån den diskreta naturen hos en elektrisk laddning. Termen tillämpas också på fotonräkning i optiska enheter, där skottbrus är associerat med ljusets partikelnatur.[1]
Se även
Referenser
- Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia, Shot noise, 26 februari 2013.
Noter
- ^ ”Shot and thermal noise”. fis.unipr.it. 14 maj 2003. Arkiverad från originalet den 8 mars 2014. https://web.archive.org/web/20140308062631/http://www.fis.unipr.it/~gigi/dida/strumentazione/harvard_noise.pdf. Läst 11 juli 2013.
Media som används på denna webbplats
Photon-noise.jpg
Författare/Upphovsman: Mdf, Licens: CC BY-SA 3.0
A photon noise simulation, using a sample image as a source and a per-pixel Poisson process to model an otherwise perfect camera (quantum efficiency = 1, no read-noise, no thermal noise, etc).
Författare/Upphovsman: Mdf, Licens: CC BY-SA 3.0
A photon noise simulation, using a sample image as a source and a per-pixel Poisson process to model an otherwise perfect camera (quantum efficiency = 1, no read-noise, no thermal noise, etc).
Going from left to right, the mean number of photons per pixel over the whole image is (top row) 0.001, 0.01, 0.1 (middle row) 1.0, 10.0, 100.0 (bottom row) 1,000.0, 10,000.0 and 100,000.0. Note the rapid increase in quality past 10 photons/pixel. (The source image was collected with a camera with a per-pixel well capacity of about 40,000 photons.)
Please click on the image to see the larger form; the low-level images are mainly isolated pixels, and your browser (or wikipedia's server) may be downsampling them to black.
Photon noise is the dominant source of noise in the images that are collected by most digital cameras on the market today. Better cameras can go to lower levels of light -- specialized, expensive, cameras can detect individual photons -- but ultimately photon shot noise determines the quality of the image.