pixfade — darken a pix file
pixfade
[-f fraction
] [-p percentage
] [-m max
] [-s squaresize
] [-w width
] [-n height
] [-o out_file.pix
] [infile.pix
] > outfile.pix
pixfade darkens a color pix file by fading the entire image a fractional amount or by using a pixel value as a maximum level.
The
-f
option specifies a nonnegative fractional multiplier which is used
to scale the red, green, and blue values of each pixel. In a similar
way, the
-p
option is used to specify the multiplier as a nonnegative percentage.
The default is -f
0.5 (-p
50.0).
An alternative way to darken the image is to specify a ceiling pixel
level (0 - 255) with the
-m
option. The pixel plotted is the minimum of the ceiling value and each of the
red, green, and blue levels of the pixel. If this option is used,
the -f
and -p
options are ignored.
The
-w
and
-n
flags specify the input file width and number of scan lines in pixels;
they can be set to the same value via
-s
. Default is 512x512.
The
-o
option
supplies output file name. If this option is omitted, standard output is used.