octave-lyh: scripts/image/ntsc2rgb.m annotate

annotate scripts/image/ntsc2rgb.m @ 17478:b8ecdb6ce2f8

assert.m: Speed up function by ~16% by not pre-calculating warning message. * scripts/testfun/assert.m: Don't pre-calculate "in" warning message since it is only used a small fraction of the time when there is an actual error.

author	Rik <rik@octave.org>
date	Mon, 23 Sep 2013 13:43:23 -0700
parents	3d2357969627
children

rev	line source
14138 72c96de7a403 maint: update copyright notices for 2012 John W. Eaton <jwe@octave.org> parents: 11587 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: 6046 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: 6046 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: 6046 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: 6046 diff changeset	17 ## <http://www.gnu.org/licenses/>.
559 4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	18
3381 69b167451491 [project @ 1999-12-15 20:48:10 by jwe] jwe parents: 3373 diff changeset	19 ## -- texinfo --
14260 1f911333ed3d doc: Update docstrings for functions in image/ directory Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	20 ## @deftypefn {Function File} {@var{rgb_map} =} ntsc2rgb (@var{yiq_map})
1f911333ed3d doc: Update docstrings for functions in image/ directory Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	21 ## @deftypefnx {Function File} {@var{rgb_img} =} ntsc2rgb (@var{yiq_img})
1f911333ed3d doc: Update docstrings for functions in image/ directory Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	22 ## Transform a colormap or image from luminance-chrominance (NTSC) space to
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	23 ## red-green-blue (RGB) color space.
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	24 ##
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 ## Implementation Note:
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 conversion matrix is chosen to be the inverse of the
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 ## matrix used for rgb2ntsc such 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	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 ## @example
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 ## x == ntsc2rgb (rgb2ntsc (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	31 ## @end example
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 ##
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 ## @sc{matlab} uses a slightly different matrix where rounding
806ea52af230 Overhaul m-files in image directory to provide better support for images stored as integers. Rik <rik@octave.org> parents: 14260 diff changeset	34 ## means the equality above does not hold.
14260 1f911333ed3d doc: Update docstrings for functions in image/ directory Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	35 ## @seealso{rgb2ntsc, hsv2rgb, ind2rgb}
3373 36405da8e173 [project @ 1999-11-23 20:54:17 by jwe] jwe parents: 3202 diff changeset	36 ## @end deftypefn
1024 56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 559 diff changeset	37
3202 44d82b369c78 [project @ 1998-10-29 20:27:57 by jwe] jwe parents: 2847 diff changeset	38 ## Author: Tony Richardson <arichard@stark.cc.oh.us>
2312 204cc7db6f4a [project @ 1996-07-11 21:20:36 by jwe] jwe parents: 2311 diff changeset	39 ## Created: July 1994
204cc7db6f4a [project @ 1996-07-11 21:20:36 by jwe] jwe parents: 2311 diff changeset	40 ## Adapted-By: jwe
1024 56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 559 diff changeset	41
2312 204cc7db6f4a [project @ 1996-07-11 21:20:36 by jwe] jwe parents: 2311 diff changeset	42 function rgb = ntsc2rgb (yiq)
1024 56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 559 diff changeset	43
56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 559 diff changeset	44 if (nargin != 1)
6046 34f96dd5441b [project @ 2006-10-10 16:10:25 by jwe] jwe parents: 5307 diff changeset	45 print_usage ();
1024 56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 559 diff changeset	46 endif
56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 559 diff changeset	47
15717 3d2357969627 NTSC images can only be of class double. Rik <rik@octave.org> parents: 15714 diff changeset	48 if (! isa (yiq, "double"))
3d2357969627 NTSC images can only be of class double. Rik <rik@octave.org> parents: 15714 diff changeset	49 error ("ntsc2rgb: YIQ must be of type double");
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	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
7375 4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	52 ## If we have an image convert it into a color map.
4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	53 if (ismatrix (yiq) && ndims (yiq) == 3)
4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	54 is_image = true;
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	55 sz = size (yiq);
7375 4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	56 yiq = [yiq(:,:,1)(:), yiq(:,:,2)(:), yiq(:,:,3)(:)];
4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	57 else
4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	58 is_image = false;
4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	59 endif
4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	60
15714 b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	61 if (! isreal (yiq) \|\| columns (yiq) != 3 \|\| issparse (yiq))
b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	62 error ("ntsc2rgb: input must be a matrix of size Nx3 or NxMx3");
7375 4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	63 endif
11587 c792872f8942 all script files: untabify and strip trailing whitespace John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	64
15714 b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	65 ## Conversion matrix constructed from 'inv (rgb2ntsc matrix)'.
b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	66 ## See programming notes in rgb2ntsc.m. Note: Matlab matrix for inverse
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	67 ## is slightly different. We prefer this matrix 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	68 ## x == ntsc2rgb (rgb2ntsc (x)) rather than maintaining strict compatibility
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 ## with Matlab.
1024 56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 559 diff changeset	70 trans = [ 1.0, 1.0, 1.0;
56520a75b5b3 [project @ 1995-01-11 20:30:04 by jwe] jwe parents: 559 diff changeset	71 0.95617, -0.27269, -1.10374;
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	72 0.62143, -0.64681, 1.70062 ];
559 4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	73
4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	74 rgb = yiq * trans;
4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	75
7375 4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	76 ## If input was an image, convert it back into one.
4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	77 if (is_image)
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	78 rgb = reshape (rgb, sz);
7375 4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	79 endif
4fbfce35012a [project @ 2008-01-15 01:04:06 by jwe] jwe parents: 7017 diff changeset	80
559 4e826edfbc56 [project @ 1994-07-25 22:18:28 by jwe] jwe parents: diff changeset	81 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	82
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
15714 b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	84 %% Test pure R, G, B colors
b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	85 %!assert (ntsc2rgb ([.299 .596 .211]), [1 0 0], 1e-5)
b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	86 %!assert (ntsc2rgb ([.587 -.274 -.523]), [0 1 0], 1e-5)
b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	87 %!assert (ntsc2rgb ([.114 -.322 .312]), [0 0 1], 1e-5)
b1cd65881592 Clean up scripts in image directory. Rik <rik@octave.org> parents: 15683 diff changeset	88
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	89 %!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	90 %! rgb_map = rand (64, 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	91 %! assert (ntsc2rgb (rgb2ntsc (rgb_map)), rgb_map, 1e-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	92
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 %!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	94 %! rgb_img = rand (64, 64, 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	95 %! assert (ntsc2rgb (rgb2ntsc (rgb_img)), rgb_img, 1e-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	96
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 %% 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	98 %!error ntsc2rgb ()
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 %!error ntsc2rgb (1,2)
15717 3d2357969627 NTSC images can only be of class double. Rik <rik@octave.org> parents: 15714 diff changeset	100 %!error <YIQ must be of type double> ntsc2rgb (uint8 (1))
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	101 %!error <must be a matrix of size Nx3 or NxMx3> ntsc2rgb (ones (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	102

Mercurial > hg > octave-lyh

annotate scripts/image/ntsc2rgb.m @ 17478:b8ecdb6ce2f8