The tool is somewhat modified from Dr. Kovesi's original Matlab code in that it works with both greyscale and RGB images (decomposes to HSI and uses the intensity data) and it handles the case of rasters that contain NoData values. This adds complexity to the original 20 additions and 5 multiplications assertion of the original paper.

Also note, for small values of sigma (< 1.8), you should probably just use the regular GaussianFilter tool.

## Reference

P. Kovesi 2010 Fast Almost-Gaussian Filtering, Digital Image Computing: Techniques and Applications (DICTA), 2010 International Conference on.

## Function Signature

`def fast_almost_gaussian_filter(self, raster: Raster, sigma: float = 1.8) -> Raster: ...`

## Project Links

WbW Homepage User Manual Support WbW