octave: scripts/image/ind2gray.m annotate

annotate scripts/image/ind2gray.m @ 15683:806ea52af230

Overhaul m-files in image directory to provide better support for images stored as integers. * NEWS: Add note about overhaul of image scripts to support integer classes. * brighten.m: Add demo. * colormap.m: Better input validation. * contrast.m: Re-position window in demo. * gray2ind.m: Redo docstring. Match variables in docstring to function prototype. Better input validation. Return integer class outputs as Matlab does. Add %!tests. * hsv2rgb.m: Add to docstring. Better input validation. Redo algorithm to get rido of obsolete matrix-fill methods like kron(). Add %!tests. * image.m: Redo docstring. Match variables in docstring to function prototype. Better input validation without using for loops. * imagesc.m: Redo docstring. Match variables in docstring to function prototype. Remove DEPRECATEDZOOM functionality. Add demos. * imfinfo.m: Redo docstring. * ind2gray.m: Redo docstring. Match variables in docstring to function prototype. Redo algorithm to directly calculate luminance value rather than getting it from rgb2ntsc. Add %!tests. * ind2rgb.m: Redo docstring. Better input validation. Add some %!tests. * ntsc2rgb.m: Redo docstring. Better input validation. Add %!tests. * rgb2hsv.m: Better input validation. Add %!tests. * rgb2ind.m: Better input validation. Code algorithm in cleaner method for ease of understanding. * rgb2ntsc.m: Redo docstring: Better input validation. Add some %!tests.

author	Rik <rik@octave.org>
date	Tue, 27 Nov 2012 16:38:13 -0800
parents	1f911333ed3d
children	a1b634240352

rev	line source
14138 72c96de7a403 maint: update copyright notices for 2012 John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	1 ## Copyright (C) 1994-2012 John W. Eaton
2313 5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	2 ##
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	3 ## This file is part of Octave.
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	4 ##
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	5 ## Octave is free software; you can redistribute it and/or modify it
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	6 ## under the terms of the GNU General Public License as published by
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6653 diff changeset	7 ## the Free Software Foundation; either version 3 of the License, or (at
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6653 diff changeset	8 ## your option) any later version.
2313 5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	9 ##
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	10 ## Octave is distributed in the hope that it will be useful, but
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	13 ## General Public License for more details.
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	14 ##
5ca126254d15 [project @ 1996-07-11 21:25:22 by jwe] jwe parents: 2312 diff changeset	15 ## You should have received a copy of the GNU General Public License
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6653 diff changeset	16 ## along with Octave; see the file COPYING. If not, see
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6653 diff changeset	17 ## <http://www.gnu.org/licenses/>.
1024 56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 917 diff changeset	18
3381 69b167451491 [project @ 1999-12-15 20:48:10 by jwe] jwe parents: 3373 diff changeset	19 ## -- texinfo --
15683 806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	20 ## @deftypefn {Function File} {@var{I} =} ind2gray (@var{x})
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	21 ## @deftypefnx {Function File} {@var{I} =} ind2gray (@var{x}, @var{map})
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	22 ## Convert a color indexed image to a grayscale intensity image.
3373 36405da8e173 [project @ 1999-11-23 20:54:17 by jwe] jwe parents: 3202 diff changeset	23 ## If @var{map} is omitted, the current colormap is used to determine the
36405da8e173 [project @ 1999-11-23 20:54:17 by jwe] jwe parents: 3202 diff changeset	24 ## intensities.
15683 806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	25 ##
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	26 ## The output @var{I} is of the same class as the input @var{x} and may be
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	27 ## one of @code{uint8}, @code{uint16}, @code{single}, or @code{double}.
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	28 ##
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	29 ## Implementation Note: There are several ways of converting colors to
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	30 ## grayscale intensities. This functions uses the luminance value obtained
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	31 ## from @code{rgb2ntsc} which is @code{I = 0.299R + 0.587G + 0.114*B}.
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	32 ## Other possibilities include the value component from @code{rgb2hsv} or
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	33 ## using a single color channel from @code{ind2rgb}.
14260 1f911333ed3d doc: Update docstrings for functions in image/ directory Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	34 ## @seealso{gray2ind, ind2rgb}
3373 36405da8e173 [project @ 1999-11-23 20:54:17 by jwe] jwe parents: 3202 diff changeset	35 ## @end deftypefn
904 3470f1e25a79 [project @ 1994-11-09 21:22:15 by jwe] jwe parents: 559 diff changeset	36
3202 44d82b369c78 [project @ 1998-10-29 20:27:57 by jwe] jwe parents: 2847 diff changeset	37 ## Author: Tony Richardson <arichard@stark.cc.oh.us>
2312 204cc7db6f4a [project @ 1996-07-11 21:20:36 by jwe] jwe parents: 2311 diff changeset	38 ## Created: July 1994
204cc7db6f4a [project @ 1996-07-11 21:20:36 by jwe] jwe parents: 2311 diff changeset	39 ## Adapted-By: jwe
559 4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	40
15683 806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	41 function I = ind2gray (x, map)
1024 56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 917 diff changeset	42
56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 917 diff changeset	43 if (nargin < 1 \|\| nargin > 2)
6046 34f96dd5441b [project @ 2006-10-10 16:10:25 by jwe] jwe parents: 5642 diff changeset	44 print_usage ();
15683 806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	45 endif
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	46
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	47 if (! isreal (x) \|\| issparse (x)
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	48 \|\| (isfloat (x) && (any (x(:) < 1 \|\| any (x(:) != fix (x(:)))))))
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	49 error ("ind2gray: X must be an indexed image");
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	50 endif
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	51 cls = class (x);
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	52 if (! any (isa (x, {"logical", "uint8", "uint16", "single", "double"})))
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	53 error ("ind2gray: invalid data type '%s'", cls);
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	54 endif
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	55
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	56 if (nargin == 1)
1024 56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 917 diff changeset	57 map = colormap ();
15683 806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	58 elseif (! iscolormap (map))
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	59 error ("ind2gray: MAP must be a valid colormap");
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	60 endif
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	61
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	62 ## Convert colormap to luminance intensity values
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	63 map *= [0.299; 0.587; 0.114];
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	64
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	65 ## Convert colormap to same class as that of input so that
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	66 ## indexing in colormap will produce output of the same type as the input.
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	67 if (isinteger (x))
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	68 map *= intmax (cls);
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	69 elseif (strcmp (cls, "single"))
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	70 map = single (map);
559 4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	71 endif
4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	72
15683 806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	73 ## Replace indices in the input matrix with the indexed luminance value.
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	74 I = reshape (map(x(:)), size (x));
559 4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	75
4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	76 endfunction
15683 806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	77
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	78
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	79 %!test
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	80 %! i2g = ind2gray (1:100, gray (100));
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	81 %! assert (i2g, 0:1/99:1, eps);
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	82 %! g2i = gray2ind (i2g, 100);
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	83 %! assert (g2i, uint8 (1:100));
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	84
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	85 %%test input validation
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	86 %!error ind2gray ()
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	87 %!error ind2gray (1,2,3)
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	88 %!error <X must be an indexed image> ind2gray ({1})
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	89 %!error <X must be an indexed image> ind2gray (1+i)
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	90 %!error <X must be an indexed image> ind2gray (sparse (1))
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	91 %!error <X must be an indexed image> ind2gray (0)
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	92 %!error <X must be an indexed image> ind2gray (1.1)
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	93 %!error <MAP must be a valid colormap> ind2gray (1, {1})
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	94 %!error <MAP must be a valid colormap> ind2gray (1, 1+i)
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	95 %!error <MAP must be a valid colormap> ind2gray (1, ones (2,2,2))
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	96 %!error <MAP must be a valid colormap> ind2gray (1, ones (2,4))
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	97 %!error <MAP must be a valid colormap> ind2gray (1, [-1])
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	98 %!error <MAP must be a valid colormap> ind2gray (1, [2])
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	99

Mercurial > octave

annotate scripts/image/ind2gray.m @ 15683:806ea52af230