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       pixborder - add a 1-pixel-wide border to	regions	of a specified color

       pixborder [-b 'R	G B'] [-e 'R G B'] [-i 'R G B']	[-t 'R G B']
		 [-B 'H	S V'] [-E 'H S V'] [-I 'H S V']	[-T 'H S V']
		 [-x left_edge]	[-y bottom_edge] [-X right_edge] [-Y top_edge]
		 [-a] [-n file_height] [-s squaresize] [-w file_width]

       pixborder reads an input	stream of pix data, looking for	maximal
       contiguous regions of a specified interior color, and writes out	the
       pix data	with all pixels	on the boundaries of these regions changed to
       a specified border color.

       The way pixborder decides if a given pixel is on	the boundary depends
       on how the user specified the interior and exterior. The	-i option
       causes pixborder	to replace the default interior	color of 255 255 255
       by R G B, while the -I option replaces it by H S	V, which are reals,
       with H in [0, 360) and S, V in [0, 1]. Similarly, the -e	and -E options
       replace the default exterior color of 1 1 1. If the user	specified
       colors for both or neither of the interior and exterior,	then a pixel
       is on the boundary provided that	it has the interior color and at least
       one of its four neighbors (left,	right, above, and below) has the
       exterior	color. If, on the other	hand, the user specified only the
       interior	(exterior) color, then a pixel is on the boundary provided
       that it has the interior	color (does not	have the exterior color) and
       at least	one of its neighbors does not have the interior	color (has the
       exterior	color).

       The -b and -B options are for the specification of what will be used
       for the border.

       Variability in the interior and exterior	colors may be accommodated by
       the -t and -T options, with which one specifies a symmetric tolerance
       for each	of the red, green, and blue channels or	hue, saturation, and
       value. Any color	within the specified tolerance of the nominal interior
       (exterior) color	is treated as though it	were the nominal color.

       The -a option is	for autosizing.	The -w option is for file width, the
       -n option is for	file height, and the -s	option sets file width and
       height to the same value. (Values are in	pixels.)

       Changes are restricted to a specified rectangular portion of the	image
       (by default this	is the entire image). The -x option sets the left edge
       of that rectangle: no pixels to the left	of this	edge are changed. The
       -X, -y, and -Y options respectively set the right, bottom, and top
       edges in	the same manner.

       To obtain borders more than one pixel wide, one can run several copies
       of pixborder in a pipeline. In doing this to get, for instance, a
       border made up of constant-thickness segments of	different colors, one
       should produce all the segments of a given layer	before beginning any
       segments	of the next inner layer.

       Paul Tanenbaum

       This software is	Copyright (c) 1996-2019	by the United States
       Government as represented by U.S. Army Research Laboratory.

       Reports of bugs or problems should be submitted via electronic mail to

BRL-CAD				  08/29/2020			  PIXBORDER(1)


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