init(device:sigma:)

Declaration

init(device: any MTLDevice, sigma: Float)

Parameters

• device:

  The Metal device the filter will run on.

• sigma:

  The standard deviation of the gaussian blur filter.

  Gaussian weight w, centered at 0, at integer grid i, is given as:

  w(i) = 1/sqrt(2*pi*sigma) * exp(-i^2/2*sigma^2)

  If we take cut off at 1% of w(0) (max weight) beyond which weights are considered 0, we have ceil(sqrt(-log(0.01)*2)*sigma) ~ ceil(3.7*sigma) as the rough estimate of the filter width.

Return Value

An initialized Gaussian blur filter object.