## Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2005, 2006, 2007
##               John W. Eaton
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or (at
## your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {} rgb2ntsc (@var{rgb})
## Image format conversion.
## @end deftypefn

## Author: Tony Richardson <arichard@stark.cc.oh.us>
## Created: July 1994
## Adapted-By: jwe

function yiq = rgb2ntsc (rgb)

  if (nargin != 1)
    print_usage ();
  endif

  trans = [ 0.299,  0.596,  0.211;
            0.587, -0.274, -0.523;
            0.114, -0.322,  0.312 ];

  yiq = rgb * trans;

endfunction