term% cat index.txt BBOX(9.1) BBOX(9.1)
NAME
bbox - compute bounding rectangle
SYNOPSIS
fb/bbox [ -s ] [ -cchannel ] [ -vvalue ] [ picture ]
DESCRIPTION
Bbox reads the given picture file (default standard input) and prints
on its standard output the minimum bounding box of the interesting pix‐
els of the image. ‘Interesting' pixels are those for which a given
channel, specified by the -c option, does not have a given value, spec‐
ified by the -v option. -v defaults to 0, and -c defaults to the α
channel (letter 'a' in the CHAN= header line) if the image contains
one, or the ‘m' channel otherwise. If the image has neither α nor
‘m', option -c is not optional. By default, therefore, bbox prints the
bounding box of the visible parts of an image with an α channel, or
the non-black parts of a monochrome image.
Option -s causes bbox to instead copy its input to standard output,
clipping the image to the bounding rectangle.
SOURCE
/sys/src/fb/bbox.c
SEE ALSO
picfile(9.6)
BBOX(9.1)