bwstat — list statistics related to a black and white bw image.
bwstat will take the given bw(5) format file, or read from standard in. A collection of statistics related to the pixel intensities is produced. These include: The number of pixels (and the square root of this, yielding the file dimension if it's square); the max and min values; the mean; the median (dividing line where half the pixels are above this value, half below); the mode (most frequently occurring value) and the number of pixels at this value; the variance, standard deviation, and skew.
flag will also dump a histogram of the pixel values.
Since the pixel values are quantized (have discrete values from 0 to 255), the statistics can be computed from "lump sums" after building a histogram of the input. This results in a fantastic savings in computation while also making a single pass over the input file sufficient.
This software is Copyright (c) 1989-2016 by the United States Government as represented by U.S. Army Research Laboratory.