Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
BWROT(1)			    BRL-CAD			      BWROT(1)

NAME
       bwrot - rotate, invert, or reverse a black and white bw file

SYNOPSIS
       bwrot [-rifb | -a angle]	[-s squaresize]	[-w in_width] [-n in_height]
	     [-o out.bw] [file.bw] [_ out.bw]

DESCRIPTION
       bwrot will rotate, vertically invert, and horizontally reverse a	black
       and white bw(5) format file or read from	standard input if a file name
       is not given. The -w and	-n flags specify the input file	width and
       number of scan lines in pixels. They can	both be	set to same value via
       -s.

       The -r flag reverses the	scan lines left	to right.  The -i flag inverts
       the image top to	bottom.	 The -f	and -b flag will rotate	the image
       ninety degrees forward or backward respectively.	The sense of the
       rotation	is relative to a first quadrant	coordinate system, i.e.	origin
       lower left, where "forward" means clockwise.

       Note that a 180 degree rotation can be obtained by both reversing and
       inverting.

       If the -a flag is used, the image will be rotated counterclockwise by
       the specified arbitrary angle.

       The -o option can be used to specify an output file instead of
       redirecting standard out.

METHOD
       A fairly	large buffer is	kept in	memory so that,	file size permitting,
       the entire rotation can occur without seeking on	input or output. In
       any event, the algorithm	is designed to process the input sequentially,
       so that if any seeking is required, it will happen on output only. If
       these seeks fail, e.g. the output is a pipe, the	user will be told that
       it needs	a file on output. A more general solution to this problem
       would be	to see if seeks	can be done on input instead, and switch the
       algorithm to seek on input only.

SEE ALSO
       brlcad(1), pixrot(1), bwscale(5), bwrect(1), bw(5)

BUGS
       If the file size	is very	large, excessive seeking may occur on output
       and the rotation	will take a very long time. More complicated
       algorithms could	remedy this.

AUTHOR
       BRL-CAD Team

COPYRIGHT
       This software is	Copyright (c) 1989-2013	by the United States
       Government as represented by U.S. Army Research Laboratory.

BUG REPORTS
       Reports of bugs or problems should be submitted via electronic mail to
       <devs@brlcad.org>.

BRL-CAD				  07/08/2017			      BWROT(1)

NAME | SYNOPSIS | DESCRIPTION | METHOD | SEE ALSO | BUGS | AUTHOR | COPYRIGHT | BUG REPORTS

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=bwrot&sektion=1&manpath=FreeBSD+12.0-RELEASE+and+Ports>

home | help