new PhotoEditorSDK.Operations.ArtFilterOperation.TensorFilters.VariancePreparationFilter()
sdk/operations/art-filter-operation/filters/variance-preparation-filter.js, line 27
This filter takes two inputs, 'x' and 'sum' and prepares the variation calculation by calculating: sqrt(x - (sum / x.size)). It's result can then be fed to a sum filter, which yields the variance of x.