--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main/image/imadjust.m	Wed Oct 10 19:54:49 2001 +0000
@@ -0,0 +1,100 @@
+## Copyright (C) 1999,2000  Kai Habel
+##
+## 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 of the License, 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 program; if not, write to the Free Software
+## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+## -*- texinfo -*-
+## @deftypefn {Function File} @var{J}= imadjust (@var{I},[low high],[bottom top],gamma)
+## the values in the range [low high] of the image I (intensity) are transformed 
+## in range [bottom top] of the resulting intensity image (J).
+## A gamma value is applied.
+## If gamma is ommitted then a linear mapping (gamma=1) is assumed.
+## 
+## @end deftypefn
+
+## o    |
+## u  ot+           ****
+## t    |        *
+## p    |     *
+## u  ob+****
+## t    |
+##      -+--+-------+--+-
+##       0  il      ih 1
+##         input range
+##
+## Author:	Kai Habel <kai.habel@gmx.de>
+## Date:	17/03/2000
+
+function ret = imadjust (I, in, out, gamma)
+
+  if (nargin < 3 || nargin > 4)
+    usage ("imadjust(...) number of arguments must be 3 or 4");
+  endif
+
+  if (nargin == 3)
+    gamma = 1;
+  else 
+    if !(is_scalar (gamma))
+      error ("imadjust(...,gamma) gamma must be a scalar");
+    else
+      if !(gamma >= 0 && gamma < Inf)
+        error ("gamma range [0,Inf)");
+      endif
+    endif
+  endif
+
+  if !(is_matrix (I))
+    error ("imadjust(I,...) I must be a image matrix or colormap");
+  endif
+
+  if !((is_vector (in) || isempty (in)) && (is_vector (out) || isempty (out)) )
+    usage ("imadjust(I,[low high],[bottom top],gamma)");
+  else
+    if (length (in) == 0)
+      il = 0;
+      ih = 1;
+    elseif (length (in) == 2)
+      il = min (in);
+      ih = max (in);
+    else
+      usage ("imadjust(I,[low high],[bottom top],gamma)");
+    endif
+
+    if (length (out) == 0)
+      ob = 0;
+      ot = 1;
+    elseif (length (out) == 2)
+      ob = out (1);
+      ot = out (2);
+
+      if (ob >= ot)
+        ob = out (1);
+        ot = out (2);
+        warning ("bottom greater top");
+      endif
+    else
+      usage ("imadjust(I,[low high],[bottom top],gamma)");
+    endif
+  endif
+
+  ret = (I < il) .* ob;
+  ret = ret + (I >= il && I < ih) .* (ob + (ot - ob) .* ((I - il) / (ih - il)) .^ gamma);
+  ret = ret + (I >= ih) .* ot;
+
+  if (in(1) > in(2))
+    # hmm don't know if this is correct for gamma!=1
+    ret = il + (ih - ret);
+  endif
+
+endfunction