pgmhist(1) General Commands Manual pgmhist(1)NAME
pgmhist - print a histogram of the values in a portable graymap
SYNOPSIS
pgmhist [pgmfile]
DESCRIPTION
Reads a portable graymap as input. Prints a histogram of the gray values.
SEE ALSO pgmnorm(1), pgm(5), ppmhist(1)AUTHOR
Copyright (C) 1989 by Jef Poskanzer.
28 February 1989 pgmhist(1)
Check Out this Related Man Page
ppmhist(1) General Commands Manual ppmhist(1)NAME
ppmhist - print a histogram of a portable pixmap
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 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 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.
17 September 2000 ppmhist(1)
What is the point of this? Whenever I close my shell it appends to the history file without adding this. I have never seen it overwrite my history file.
# When the shell exits, append to the history file instead of overwriting it
shopt -s histappend (3 Replies)