Usage: nearblack [--help] [--long-usage] [--help-general]
                 [-of <output_format>] [--quiet] [-co <NAME>=<VALUE>]...
                 [-o <output_file>]
                 [[-white]|[-color <c1,c2,c3...cn>]...]
                 [-nb <non_black_pixels>] [-near <dist>] [-setalpha] [-setmask]
                 [-alg floodfill|twopasses]
                 <input_file>

Note: nearblack --long-usage for full help.