Interpolate DSM's to fill holes.
Default value(s): method = from lowest, radius = 30 pixels, minimal points = 4
The default interpolation method "from lowest" tries to extend low elevation parts/samples within the specified mask. This approach specifically tries to acquire sharp edges in the DSM's and consective True Ortho's, by extending potential ground areas up to the roof edges, and thereby especially avoids just smoothing over these edges. If less than the specified minimal points are found within the mask, no value will be interpolated and NaN will be assigned to the pixel.
The second interpolation method "IWD" employs the inverse weighted distance for weighing the pixel's values. Increasing the power parameter will lead to amplified weights in the mask's center, or damped weights in the mask's edges/corners, respectively. The number of minimal points in quadrant is similar to the minimal points, however, it will be evaluated for each quadrant (upper left, lower left, upper right, lower right) separately, so valid information from each quadrant are required for the interpolation.