Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / image-1.0.15 / im2double.m

diff --git a/octave_packages/image-1.0.15/im2double.m b/octave_packages/image-1.0.15/im2double.m
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+## Copyright (C) 2007  Søren Hauberg
+## 
+## 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 Foundation; either version 2, or (at your option)
+## any later version.
+## 
+## This program 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 this file.  If not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} @var{im2} = im2double(@var{im1})
+## Converts the input image to an image of class double.
+##
+## If the input image is of class double the output is unchanged.
+## If the input is of class uint8 the result will be converted to doubles
+## and divided by 255, and if the input is of class uint16 the image will
+## be converted to doubles and divided by 65535.
+## @seealso{im2bw, im2uint16, im2uint8}
+## @end deftypefn
+
+function im2 = im2double(im1)
+  ## Input checking
+  if (nargin < 1)
+    print_usage();
+  endif
+  if (!isgray(im1) && !isrgb(im1))
+    error("im2double: input must be an image");
+  endif
+  
+  ## Take action depending on the class of the data
+  switch (class(im1))
+    case "double"
+      im2 = im1;
+    case "uint8"
+      im2 = double(im1) / 255;
+    case "uint16"
+      im2 = double(im1) / (pow2(16)-1);
+    otherwise
+      error("im2double: unsupported image class");
+  endswitch
+endfunction