Contrast-to-noise ratio

Contrast-to-noise ratio
Haze over Kuala Lumpur.

Contrast-to-noise ratio (CNR) is a measure used to determine image quality. CNR is similar to the metric, signal-to-noise ratio (SNR), but subtracts off a term before taking the ratio. This is important when there is a significant bias in an image, such as from haze. As can be seen in the picture at right, the intensity is rather high even though the features of the image are washed out by the haze. Thus this image may have a high SNR metric, but will have a low CNR metric.

One way to define contrast-to-noise ratio is:

C = \frac{|S_A-S_B|}{\sigma_o}

where SA and SB are signal intensities for signal producing structures A and B in the region of interest and σo is the standard deviation of the pure image noise.

See also

v · d · eNoise (in physics and telecommunications)
General
Noise in...
Class of noise
Engineering terms
Ratios
Carrier-to-noise ratio (C/N) · Carrier-to-receiver noise density (C/kT) · dBrnC · Eb/N0 (energy per bit to noise density) · Es/N0 (energy per symbol to noise density) · Modulation error ratio (MER) · Signal, noise and distortion (SINAD) · Signal-to-interference ratio (S/I) · Signal-to-noise ratio (S/N, SNR) · Signal to noise ratio (imaging) · Signal-to-noise plus interference (SNIR) · Signal-to-quantization-noise ratio (SQNR)
Related topics

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