--- /dev/null
+## Copyright (C) 1994-2012 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} {} image (@var{img})
+## @deftypefnx {Function File} {} image (@var{x}, @var{y}, @var{img})
+## @deftypefnx {Function File} {@var{h} =} image (@dots{})
+## Display a matrix as a color image. The elements of @var{img} are indices
+## into the current colormap, and the colormap will be scaled so that the
+## extremes of @var{img} are mapped to the extremes of the colormap.
+##
+## The axis values corresponding to the matrix elements are specified in
+## @var{x} and @var{y}. If you're not using gnuplot 4.2 or later, these
+## variables are ignored.
+##
+## Implementation Note: The origin (0, 0) for images is located in the
+## upper left. For ordinary plots, the origin is located in the lower
+## left. Octave handles this inversion by plotting the data normally,
+## and then reversing the direction of the y-axis by setting the
+## @code{ydir} property to @code{"reverse"}. This has implications whenever
+## an image and an ordinary plot need to be overlaid. The recommended
+## solution is to display the image and then plot the reversed ydata
+## using, for example, @code{flipud (ydata,1)}.
+##
+## The optional return value @var{h} is a graphics handle to the image.
+## @seealso{imshow, imagesc, colormap}
+## @end deftypefn
+
+## Author: Tony Richardson <arichard@stark.cc.oh.us>
+## Created: July 1994
+## Adapted-By: jwe
+
+function retval = image (varargin)
+
+ [ax, varargin, nargin] = __plt_get_axis_arg__ ("image", varargin{:});
+
+ firstnonnumeric = Inf;
+ for i = 1 : nargin
+ if (! isnumeric (varargin{i}))
+ firstnonnumeric = i;
+ break;
+ endif
+ endfor
+
+ if (nargin == 0 || firstnonnumeric == 1)
+ img = imread ("default.img");
+ x = y = [];
+ elseif (nargin == 1 || firstnonnumeric == 2)
+ img = varargin{1};
+ x = y = [];
+ elseif (nargin == 2 || firstnonnumeric == 3)
+ print_usage ();
+ else
+ x = varargin{1};
+ y = varargin{2};
+ img = varargin{3};
+ firstnonnumeric = 4;
+ endif
+
+ oldax = gca ();
+ unwind_protect
+ axes (ax);
+ h = __img__ (x, y, img, varargin {firstnonnumeric:end});
+ set (ax, "layer", "top");
+ unwind_protect_cleanup
+ axes (oldax);
+ end_unwind_protect
+
+ if (nargout > 0)
+ retval = h;
+ endif
+
+endfunction
+
+## Generic image creation.
+##
+## The axis values corresponding to the matrix elements are specified in
+## @var{x} and @var{y}. If you're not using gnuplot 4.2 or later, these
+## variables are ignored.
+
+## Author: Tony Richardson <arichard@stark.cc.oh.us>
+## Created: July 1994
+## Adapted-By: jwe
+
+function h = __img__ (x, y, img, varargin)
+
+ newplot ();
+
+ if (isempty (img))
+ error ("__img__: matrix is empty");
+ endif
+
+ if (isempty (x))
+ x = [1, columns(img)];
+ endif
+
+ if (isempty (y))
+ y = [1, rows(img)];
+ endif
+
+ xdata = [x(1), x(end)];
+ ydata = [y(1), y(end)];
+
+ dx = diff (x);
+ dy = diff (y);
+ dx = std (dx) / mean (abs (dx));
+ dy = std (dy) / mean (abs (dy));
+ tol = 100*eps;
+ if (any (dx > tol) || any (dy > tol))
+ warning ("Image does not map to non-linearly spaced coordinates")
+ endif
+
+ ca = gca ();
+
+ tmp = __go_image__ (ca, "cdata", img, "xdata", xdata, "ydata", ydata,
+ "cdatamapping", "direct", varargin {:});
+
+ px = __image_pixel_size__ (tmp);
+
+ if (xdata(2) < xdata(1))
+ xdata = xdata(2:-1:1);
+ elseif (xdata(2) == xdata(1))
+ xdata = xdata(1) + [0, size(img,2)-1];
+ endif
+ if (ydata(2) < ydata(1))
+ ydata = ydata(2:-1:1);
+ elseif (ydata(2) == ydata(1))
+ ydata = ydata(1) + [0, size(img,1)-1];
+ endif
+ xlim = xdata + [-px(1), px(1)];
+ ylim = ydata + [-px(2), px(2)];
+
+ ## FIXME -- how can we do this and also get the {x,y}limmode
+ ## properties to remain "auto"? I suppose this adjustment should
+ ## happen automatically in axes::update_axis_limits instead of
+ ## explicitly setting the values here. But then what information is
+ ## available to axes::update_axis_limits to determine that the
+ ## adjustment is necessary?
+ set (ca, "xlim", xlim, "ylim", ylim);
+
+ if (ndims (img) == 3)
+ if (isinteger (img))
+ c = class (img);
+ mn = intmin (c);
+ mx = intmax (c);
+ set (ca, "clim", double ([mn, mx]));
+ endif
+ endif
+
+ set (ca, "view", [0, 90]);
+
+ if (strcmp (get (ca, "nextplot"), "replace"))
+ # Always reverse y-axis for images, unless hold is on
+ set (ca, "ydir", "reverse");
+ endif
+
+ if (nargout > 0)
+ h = tmp;
+ endif
+
+endfunction
+
+%!demo
+%! clf
+%! img = 1 ./ hilb (11);
+%! x = -5:5;
+%! y = x;
+%! subplot (2,2,1)
+%! h = image (abs(x), abs(y), img);
+%! set (h, "cdatamapping", "scaled")
+%! ylabel ("limits = [4.5, 15.5]")
+%! title ('image (abs(x), abs(y), img)')
+%! subplot (2,2,2)
+%! h = image (-x, y, img);
+%! set (h, "cdatamapping", "scaled")
+%! title ('image (-x, y, img)')
+%! subplot (2,2,3)
+%! h = image (x, -y, img);
+%! set (h, "cdatamapping", "scaled")
+%! title ('image (x, -y, img)')
+%! ylabel ("limits = [-5.5, 5.5]")
+%! subplot (2,2,4)
+%! h = image (-x, -y, img);
+%! set (h, "cdatamapping", "scaled")
+%! title ('image (-x, -y, img)')
+
+%!demo
+%! clf
+%! g = 0.1:0.1:10;
+%! h = g'*g;
+%! imagesc (g, g, sin (h));
+%! hold on
+%! imagesc (g, g+12, cos (h/2));
+%! axis ([0 10 0 22])
+%! hold off
+%! title ("two consecutive images")
+
+%!demo
+%! clf
+%! g = 0.1:0.1:10;
+%! h = g'*g;
+%! imagesc (g, g, sin (h));
+%! hold all
+%! plot (g, 11.0 * ones (size (g)))
+%! imagesc (g, g+12, cos (h/2));
+%! axis ([0 10 0 22])
+%! hold off
+%! title ("image, line, image")
+
+%!demo
+%! clf
+%! g = 0.1:0.1:10;
+%! h = g'*g;
+%! plot (g, 10.5 * ones (size (g)))
+%! hold all
+%! imagesc (g, g, sin (h));
+%! plot (g, 11.0 * ones (size (g)))
+%! imagesc (g, g+12, cos (h/2));
+%! plot (g, 11.5 * ones (size (g)))
+%! axis ([0 10 0 22])
+%! hold off
+%! title ("line, image, line, image, line")
+
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff