Histogram Variance

Calculates the variance of all pixels in a buffer, given a histogram.

Inputs

Histogram (Type: Histogram)

The input histogram.

Outputs

Variance (Type: Object)

The variance.

Comments

The Histogram Variance node calculates the variance of all pixel values of a buffer, given a histogram to it.

If a color buffer is used, the variance is calculated channel-wise.

The variance is a measure of statistical dispersion, averaging the squared distance of values from the mean value. The variance is a measure of how much a statistical distribution is spread out.

The variance is calculated according to this formula:

\(\sigma^2 = \frac {1}{n} \sum x^2 - \mu^2\)

Sample

Here is an example that calculates the variance of a histogram.