Signal-to-noise ratio (imaging)

Signal-to-noise ratio (SNR) is used in <a href="/facts/Imaging/Lkw7V9M8">imaging</a> to characterize <a href="/facts/Image_quality/hSzpSszC">image quality</a>. The <a href="/facts/Sensitometry/mDWEXXSy">sensitivity</a> of a <a href="/facts/Photography/ezLPT43M">(digital or film) imaging system</a> is typically described in the terms of the signal level that yields a threshold level of SNR.
Industry standards define sensitivity in terms of the <a href="/facts/Film_speed/HjnLPrIb">ISO film speed</a> equivalent, using SNR thresholds (at average scene luminance) of 40:1 for "excellent" image quality and 10:1 for "acceptable" image quality.
SNR is sometimes quantified in <a href="/facts/Decibels/0LyxAPXh">decibels</a> (dB) of signal <a href="/facts/Power_(physics)/mkaEyRnn">power</a> relative to noise power, though in the imaging field the concept of "power" is sometimes taken to be the power of a voltage signal proportional to optical power; so a 20 dB SNR may mean either 10:1 or 100:1 optical power, depending on which definition is in use.

Signal-to-noise ratio (imaging) open-in-new

Signal-to-noise ratio (imaging)