Grid Merging Menu

Launches the processes for merging grids:

• Merge Grids merges all grids in the input directory by patching them onto the merged grid in a reverse priority order (i.e. the worst grids are placed at the bottom, the best on top). 
• Feather And Merge Grids feathers the grids in the input directory onto the merged grid. Residual differences along the grid edges are removed by propagating them into the overlapping grids by distances proportional to their wavelength (up to a maximum of featherDistance). 

Merge Grids is fast; Feather And Merge Grids is slow. While searching for the optimal parameters, run Merge Grids using a coarse cell size to speed up the merge. Once you are happy with the result, run Feather And Merge Grids using your desired cell size.