QgsRuggednessFilter class

Calculates the ruggedness index based on a 3x3 moving window.

Contents

Algorithm from Riley et al. 1999: A terrain ruggedness index that quantifies topographic heterogeneity

Base classes

class QgsNineCellFilter
Base class for raster analysis methods that work with a 3x3 cell filter and calculate the value of each cell based on the cell value and the eight neighbour cells.

Protected functions

auto processNineCellWindow(float* x11, float* x21, float* x31, float* x12, float* x22, float* x32, float* x13, float* x23, float* x33) -> float override
Calculates output value from nine input values.

Function documentation

float QgsRuggednessFilter::processNineCellWindow(float* x11, float* x21, float* x31, float* x12, float* x22, float* x32, float* x13, float* x23, float* x33) override protected

Calculates output value from nine input values.

The input values and the output value can be equal to the nodata value if not present or outside of the border. Must be implemented by subclasses