public bool CombineGradientPolygons { get; set; }

Property Value

Metafiles do not support gradient brushes. Therefore gradient effects are simulated with many polygons where each of them have slightly different brush applied.

This is problematic because creating many polygon elements can affect performance and increase memory usage. Even bigger problem with this is that because of the way WPF is doing antialiazing a lines can appear between the polygons regardless the fact that they are created in such a way that there should not ba any line beteen them.

To overcome those two problems the ReaderWmf library can combine the polygons that have similar brushes (are used to simulate gradient) and have common points (are created one by another).

This functionality is controlled by CombineGradientPolygons property. By default the property is set to true.

Reference