All options can be abbreviated to their shortest unique prefix. You may use two hyphens instead of one. You may separate an option name and its value with white space instead of an equals sign.
This program is part of Netpbm.
ppmrough generates a PPM image of the specified width and height. The image consists of a rectangle of the specified foreground color surrounded by borders of the specified size and background color, except that the boundary between the foreground rectangle and the borders is ragged. The ragged effect is random.
ppmrough writes the PPM image to Standard Output.
The maxval of the output image is 255 (You can change this with pamdepth).
Use the options -left or -right, respectively, to make vertical borders, and -top or -bottom, respectively, to generate horizontal borders inside the image. The value of each of these options is the minimum width of the border on that edge. Beyond that minimum, the width at any given location on that edge is random, varying along the edge in a fractal kind of way.
Use the -var option to control the "raggedness" of the border. The lower its value, the smoother the border is. You can initialize the pseudo-random generator with the -init option.
You could use ppmrough with ppmtopgm to create a PGM transparency mask and use it to roughen up the edges of another image.
In addition to the options common to all programs based on libnetpbm (most notably -quiet, see Common Options), ppmrough recognizes the following command line options:
This must be a nonnegative integer. The default is 10.
You can use this to cause the program to produce repeatable output.
Before Netpbm 10.61 (December 2012), this is called -init, and that still works.
This program was added to Netpbm in Release 10.9 (September 2002).