option "input" i "Input image filename" string required
option "output" o "Output image filename" string required
-option "lower" l "Lower intensity (default=min), fg is greater than this value" double optional
-option "upper" u "Upper intensity (default=max), fg is lower than this value" double optional
-option "fg" - "Foreground (FG) or 'inside' value" double optional default="1"
-option "bg" - "Background (BG) or 'ouside' value" double optional default="0"
-option "mode" - "Use FG and/or BG values (if FG, the BG is replaced by the input image values)" values="FG","BG","both" default="both" optional