option "input" i "Input image" string yes
option "output" o "Output mesh file prefix (if empty, use input file's base name as prefix; if a directoy, output to it using input file's base name as prefix; otherwise, use given name as prefix ; if names ends with .vtk the output is written as a vtkPolyData file" string no
option "input" i "Input image" string yes
option "output" o "Output mesh file prefix (if empty, use input file's base name as prefix; if a directoy, output to it using input file's base name as prefix; otherwise, use given name as prefix ; if names ends with .vtk the output is written as a vtkPolyData file" string no