bw file formats

bw - black and white image file format and utilities

a bw file contains sequences of pixels. each pixel is
stored as one unsigned char, and thus ranges in intensity
from 0 (black) to 255 (white). the first pixel in a bw file
is the lower left corner of the image. the pixels proceed
from left-to-right across each scanline, with scanlines
being written from the bottom to the top of the image.

by convention, bw images are usually square, and thus their
dimensions can be determined by the file size. if this is
not the case, often only the file width need be known by a
program reading the file. history has left us with two
"standard" sizes, 512x512 and the "hires" 1024x1024. a com-
mon practice for other file sizes is to include the file
width in the filename.

at some time in the future bw files will probably get self-
typing headers so that parameters such as their size can be
automatically determined by programs.

bw-fb display a .bw format image on a framebuffer.
fb-bw produce a .bw file from a framebuffer image.
bw-pix convert a .bw file to a color .pix file.
pix-bw convert a color .pix file to a .bw file.
bwstat gives statistics concerning a .bw file.
bwhist displays a histogram on a framebuffer.
bwmod a filter to shift and scale pixel intensities.
bwdiff yields the difference between two .bw files.
bwrect extracts an arbitrary rectangle from a .bw file.
bwcrop maps any quadrilateral in a .bw file into any rectan-
bwrot rotates, reverses, or inverts a .bw file.
bwscale scales a .bw file larger or smaller.
bwfilter a variety of 3x3 kernel filters for .bw images.
bw3-pix merges three .bw files into one .pix file.
pix-bw3 separates .pix file rgb colors into three .bw files.


see also
brlcad(1), pix(5), and above named programs.