NAME
    ppmhist - print a histogram of a PPM image

SYNOPSIS
    ppmhist [-hexcolor] [-noheader] [-map] [-nomap] [-sort={frequency,rgb}]
    [ppmfile]

DESCRIPTION
    Reads a PPM image as input. Generates a histogram of the colors in the
    image, i.e. a list of all the colors and how many pixels of each color
    are in the image.

OPTIONS
    -sort={frequency,rgb}
    The -sort option determines the order in which the colors are
    listed in the output. frequency means to list them in order of
    how pixels in the input image have the color, with the most rep-
    resented colors first.  rgb means to sort them first by the
    intensity of the red component of the color, the of the green,
    then of the blue, with the least intense first.

    The default is frequency.

    -hexcolor
    Print the color components in hexadecimal. Default is decimal.

    -noheader
    Do not print the column headings.

    -map  Generates a PPM file of the colormap for the image, with the
    color histogram as comments.

    -nomap Generates the histogram for human reading. This is the default.

SEE ALSO
    ppm(5),pgmhist(1),ppmtomap(1),pnmhistmap(1),ppmchange(1)

AUTHOR
    Copyright (C) 1989 by Jef Poskanzer.