Man page 1 : ppmhist

ppmhist - print a histogram of a portable pixmap

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

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.

R -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 represented 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

R 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.

R ppm (5),

R pgmhist (1),

R ppmtomap (1),

R pnmhistmap (1),

R ppmchange (1)

Copyright (C) 1989 by Jef Poskanzer.