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 pixels of the image. `Interesting' pixels are those for which a given channel, specified by the -c option, does not have a given value, specified by the -v option. -v defaults to 0, and -c defaults to the ALPHA channel (letter 'a' in the CHAN= header line) if the image contains one, or the `m' channel otherwise. If the image has neither ALPHA nor `m', option -c is not optional. By default, therefore, bbox prints the bounding box of the visible parts of an image with an ALPHA 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)