Smoothing of the outlines of complex patches is a typical example, which may require conversion from raster to the
vector structure. The visual quality that can be achieved by smoothing algorithms in the raster domain, for instance
mode filtering, or erode smoothing (Monmonier 1983) is limited by the resolution of the dataset. Other raster based
methods work with resampling of the raster grid to a higher resolution (oversampling). Depending on the oversampling
factor chosen (e.g., 4) each raster cell would then consist of a number of sub-cells (e.g., 16 for factor 4). The smoothing
effect is achieved by removing or adding sub-cells as illustrated in figure 9. This method can result in a considerable
increase of the amount of data and stepped lines may still be visible unless the size of the sub-cells is below the minimum
visual separability distance.