StdDev

Calculates the standard deviation of all pixels in a buffer.

Inputs

Buffer (Type: Buffer)

The input buffer.

Region (Type: Region)

An optional region.

Outputs

StdDev (Type: Object)

The standard deviation.

Comments

The StdDev node calculates the standard deviation of all pixel values of a buffer.

If the Region input is connected, the calculation of the standard deviation is constrained to the pixels within the region only, otherwise the whole buffer is used.

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

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

The standard deviation is calculated according to this formula:

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

Sample

Here is an example that calculates the standard deviation of an image.