Mercurial > hg > octave-image
changeset 842:006ab95a7e07
im2bw: implement behaviour for unrecognized numeric matrices.
* im2bw.m: use the isimage() private function to check input. For binary
matrices return the input (do nothing, even if thresh is 0). Don't require
threshold input to be of class double. Treat any matrix of weird dimensions
as grayscale, i.e., no conversion, just threshold it.
| author | Carnë Draug <carandraug@octave.org> |
|---|---|
| date | Wed, 13 Nov 2013 04:43:48 +0000 |
| parents | d197c65d85c6 |
| children | 98c59bb02d0d |
| files | inst/im2bw.m |
| diffstat | 1 files changed, 24 insertions(+), 11 deletions(-) [+] |
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--- a/inst/im2bw.m +++ b/inst/im2bw.m @@ -1,5 +1,5 @@ ## Copyright (C) 2000 Kai Habel <kai.habel@gmx.de> -## Copyright (C) 2012 Carnë Draug <carandraug+dev@gmail.com> +## Copyright (C) 2012, 2013 Carnë Draug <carandraug@octave.org> ## ## This program 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 @@ -39,18 +39,28 @@ ## @end deftypefn function BW = im2bw (img, cmap, thres) + if (nargin < 1 || nargin > 3) - print_usage; - elseif (nargin == 3 && !isind (img)) - error ("im2bw: there must be only two arguments for non indexed images") - elseif (nargin == 3 && !iscolormap (cmap)) - error ("im2bw: `cmap' must be the a colormap for indexed images") + print_usage (); + elseif (nargin == 3 && ! isind (img)) + error ("im2bw: there must be only two arguments for non indexed images"); + elseif (nargin == 3 && ! iscolormap (cmap)) + error ("im2bw: CMAP must be the a colormap for indexed images"); elseif (nargin == 2) thres = cmap; endif - if (!isnumeric (thres) || !isscalar (thres) || !isreal (thres) || !isa (thres, "double") || thres < 0 || thres > 1) - error ("im2bw: `threshold' must be a scalar of class double in the interval [0, 1]") + if (! isimage (img)) + error ("im2bw: IMG must be an image"); + elseif (! isnumeric (thres) || ! isscalar (thres) || ! isreal (thres) || + thres < 0 || thres > 1) + error ("im2bw: THRESHOLD must be a scalar in the interval [0, 1]"); + endif + + if (islogical (img)) + warning ("im2bw: IMG is already binary so nothing is done"); + BW = img; + return endif ## Convert img to gray scale @@ -59,10 +69,8 @@ img = ind2gray (img, cmap); elseif (isrgb (img)) img = rgb2gray (img); - elseif (isgray (img)) - ## do nothing. All is good else - error ("im2bw: first input argument must be an image"); + ## Everything else, we do nothing, no matter how many dimensions endif ## Convert the threshold value to same image class to do the thresholding which @@ -86,3 +94,8 @@ %!assert(im2bw ([0 0.4 0.5 0.6 1], 0.5), logical([0 0 0 1 1])); # basic usage %!assert(im2bw (uint8 ([0 100 255]), 0.5), logical([0 0 1])); # with a uint8 input + +## This will issue a warning +%!assert (im2bw (logical ([0 1 0])), logical ([0 1 0])) +%!assert (im2bw (logical ([0 1 0]), 0), logical ([0 1 0])) +%!assert (im2bw (logical ([0 1 0]), 1), logical ([0 1 0]))