TCG Challenge #1CALCULATING CAMERA SNR

Agenda•SNR definition

•Calculation Method

•Visual Results

•Results

•Conclusions

DefinitionTraditionally, SNR has been defined as the ratio of the average signal value to the standard deviation of the background.

However, when presented with a high-contrast scene, many imaging systems clamp the background to uniform black, forcing to zero, artificially making the SNR infinite.

In this case a better definition of SNR is the ratio of the average signal value to the standard deviation of the signal.

Method Following the definition we calculate the “average of the signal” defining each pixel along the samples as a signal and using the arithmetic mean.

Arithmetic Mean (Mn) = ++ ..... +

In order to be able to calculate the standard deviation from each signal we then need to calculate the true value of each signal/pixel to conform the “True Image” we determine each pixel of this image using the arithmetic mean, the median and mode as average to determine which one yields better results.

Median (Md) =

Mode (Mo) = the most repeated value

Standard Deviation (SDi) =

Visual Results “True Image” ORIGINAL IMAGE “TRUE IMAGE” BASED ON MEAN

Visual Results “True Image” ORIGINAL IMAGE “TRUE IMAGE” BASED ON MEDIAN

Visual Results “True Image” ORIGINAL IMAGE “TRUE IMAGE” BASED ON MODE

Median vs Mean vs Mode

Results

Djalma Jonatas Victor Graziele Renato0

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mean median mode

20 log10𝑆𝑁𝑅

Conclusion