1 ## Copyright (C) 2008-2012 Thomas L. Scofield <scofield@calvin.edu>
2 ## Copyright (C) 2008 Kristian Rumberg <kristianrumberg@gmail.com>
3 ## Copyright (C) 2006 Thomas Weber <thomas.weber.mail@gmail.com>
4 ## Copyright (C) 2005 Stefan van der Walt <stefan@sun.ac.za>
5 ## Copyright (C) 2002 Andy Adler
7 ## This file is part of Octave.
9 ## Octave is free software; you can redistribute it and/or modify it
10 ## under the terms of the GNU General Public License as published by
11 ## the Free Software Foundation; either version 3 of the License, or (at
12 ## your option) any later version.
14 ## Octave is distributed in the hope that it will be useful, but
15 ## WITHOUT ANY WARRANTY; without even the implied warranty of
16 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 ## General Public License for more details.
19 ## You should have received a copy of the GNU General Public License
20 ## along with Octave; see the file COPYING. If not, see
21 ## <http://www.gnu.org/licenses/>.
24 ## @deftypefn {Function File} {[@var{img}, @var{map}, @var{alpha}] =} imread (@var{filename})
25 ## Read images from various file formats.
27 ## The size and numeric class of the output depends on the
28 ## format of the image. A color image is returned as an
29 ## @nospell{MxNx3} matrix. Gray-level and black-and-white images are
30 ## of size @nospell{MxN}.
31 ## The color depth of the image determines the numeric
32 ## class of the output: "uint8" or "uint16" for gray
33 ## and color, and "logical" for black and white.
35 ## @seealso{imwrite, imfinfo}
38 function varargout = imread (filename, varargin)
44 if (! ischar (filename))
45 error ("imread: FILENAME must be a string");
48 filename = tilde_expand (filename);
50 fn = file_in_path (IMAGE_PATH, filename);
53 error ("imread: cannot find %s", filename);
57 [varargout{1:nargout}] = __magick_read__ (fn, varargin{:});
60 magick_error = lasterr ();
69 img_field = isfield (vars, "img");
70 x_field = isfield (vars, "X");
71 map_field = isfield (vars, "map");
74 error ("imread: invalid image file: %s", magick_error);
77 if (map_field && (img_field || x_field))
78 varargout{2} = vars.map;
80 varargout{1} = vars.img;
82 varargout{1} = vars.X;
85 error ("imread: invalid Octave image file format");
94 %! 137, 80, 78, 71, 13, 10, 26, 10, 0, 0, ...
95 %! 0, 13, 73, 72, 68, 82, 0, 0, 0, 3, ...
96 %! 0, 0, 0, 3, 8, 2, 0, 0, 0, 217, ...
97 %! 74, 34, 232, 0, 0, 0, 1, 115, 82, 71, ...
98 %! 66, 0, 174, 206, 28, 233, 0, 0, 0, 4, ...
99 %! 103, 65, 77, 65, 0, 0, 177, 143, 11, 252, ...
100 %! 97, 5, 0, 0, 0, 32, 99, 72, 82, 77, ...
101 %! 0, 0, 122, 38, 0, 0, 128, 132, 0, 0, ...
102 %! 250, 0, 0, 0, 128, 232, 0, 0, 117, 48, ...
103 %! 0, 0, 234, 96, 0, 0, 58, 152, 0, 0, ...
104 %! 23, 112, 156, 186, 81, 60, 0, 0, 0, 25, ...
105 %! 73, 68, 65, 84, 24, 87, 99, 96, 96, 96, ...
106 %! 248, 255, 255, 63, 144, 4, 81, 111, 101, 84, ...
107 %! 16, 28, 160, 16, 0, 197, 214, 13, 34, 74, ...
108 %! 117, 213, 17, 0, 0, 0, 0, 73, 69, 78, ...
109 %! 68, 174, 66, 96, 130];
110 %! fid = fopen('test.png', 'wb');
111 %! fwrite(fid, vpng);
113 %! A = imread('test.png');
114 %! delete('test.png');
115 %! assert(A(:,:,1), uint8 ([0, 255, 0; 255, 237, 255; 0, 255, 0]));
116 %! assert(A(:,:,2), uint8 ([0, 255, 0; 255, 28, 255; 0, 255, 0]));
117 %! assert(A(:,:,3), uint8 ([0, 255, 0; 255, 36, 255; 0, 255, 0]));