# Refinement Mode

In addition to specifying a smoothness value, you can also specify the refinement mode. The refinement mode determines how finely PatFlex refines the computed transformation. The following table defines the available refinement mode values:

Refinement Mode | Description
--- | ---
None | No attempt is made to remove residual error from the computed transformation.
Coarse | The computed transformation is refined so that it has no more residual error than the specified coarse granularity limit.
Medium | The same as coarse refinement, except that certain types of high-level inaccuracy are removed.
Fine | Same as medium refinement, except that the transformation is refined so that it has no more residual error than the specified fine granularity limit.