fb-bw — save a framebuffer image in a black and white bw file


fb-bw [-i ] [-F framebuffer] [-X scr_xoff] [-Y scr_yoff] [-s squaresize] [-w width] [-n height] []


fb-bw will take a region of a framebuffer display and save it as a black and white bw(5) format file. The environment variable FB_FILE is used to select the display device (see brlcad(1)). If this variable is not set, the default device for your system will be used. Alternatively, the framebuffer may be explicitly specified by using the -F flag.

By default, the output file will be size 512x512 pixels. The -s flag will set both the file height and width to be the given size, while -w and -n are used for setting them individually.

A first quadrant coordinate system is used (origin in lower left of screen), and the area saved is normally from this origin. The -X and -Y flags can be used to move the origin to an offset position on the screen. The -i flag switches to a fourth quadrant system, both in the storage order as well as the origin offset coordinates (i.e. origin is now the upper left corner of the screen).

An equal blending of red, green, and blue is done. For more complicated black and white conversion use fb-pix(1) and pix-bw(1).


brlcad(1), bw-fb(1), fb-pix(1), pix-bw(1), bw(5)




This software is Copyright (c) 1989-2016 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 <>.