--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/image/imread.m	Sat Jul 12 10:11:30 2008 -0400
@@ -0,0 +1,192 @@
+## Copyright (C) 2002 Andy Adler
+## Copyright (C) 2005 Stefan van der Walt <stefan@sun.ac.za>
+## Copyright (C) 2006 Thomas Weber <thomas.weber.mail@gmail.com>
+## Copyright (C) 2008 Kristian Rumberg <kristianrumberg@gmail.com>
+## Copyright (C) 2008 Thomas L. Scofield <scofield@calvin.edu>
+##
+## This file is part of Octave.
+##
+## Octave 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 3 of the License, or (at
+## your option) any later version.
+##
+## Octave 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 Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{I} =} imread(@var{filename})
+## Read images from various file formats.
+##
+## The size and numeric class of the output depends on the
+## format of the image.  A colour image is returned as an
+## MxNx3 matrix.  Grey-level and black-and-white images are
+## of size MxN.
+## The colour depth of the image determines the numeric
+## class of the output: 'uint8' or 'uint16' for grey
+## and colour, and 'logical' for black and white.
+##
+## Note: For image formats other than jpeg and png, the
+## ImageMagick "convert" and "identify" utilities
+## are needed. ImageMagick can be found at www.imagemagick.org
+## @end deftypefn
+
+## Author: Andy Adler
+##
+## Modified: Stefan van der Walt <stefan@sun.ac.za>
+## Date: 24 January 2005
+##
+## Modified: Thomas Weber <thomas.weber.mail@gmail.com>
+## Date: 20 December 2006
+## Change parsing of imagemagick's output to get the 'color' depth for grayscale
+## images
+##
+## Modified Kristian Rumberg <kristianrumberg@gmail.com>
+## Date 2 April 2008
+## Imread now works with BMP's created with "convert inputimage out.bmp"
+## (tested with stable release Octave 3.0 in GNU/Linux and Windows XP),
+## modified the calling parameters to identify and convert
+##
+## Modified Thomas Scofield <scofield 'at' calvin.edu
+## Date 1 July 2008
+## Imread now uses Magick++ API to GraphicsMagick libraries instead
+## of ImageMagick libraries (tested with stable release Octave 3.0
+## in GNU/Linux).  All images are read by GraphicsMagick routines;
+## there is no longer exceptional handling of .png and .jpg files.
+
+function varargout = imread ( filename, varargin )
+  if (nargin < 1)
+    usage ("I = imread(filename)")
+  endif
+
+  if (!ischar (filename))
+    error ("imread: filename must be a string")
+  endif
+
+  filename = tilde_expand (filename);
+  fn = file_in_path ( IMAGE_PATH, filename );
+  if (isempty (fn))
+    error ( "imread: cannot find %s", filename );
+  endif
+
+  [ig, ig, ext] = fileparts (fn);
+  ext = upper (ext);    
+    
+  ## real work uses GraphicsMagick
+  if ( file_in_loadpath ("__magick_read__.oct") )
+    [varargout{1:nargout}] = __magick_read__ ( fn, varargin{:} );
+    ## color .PNG formats (any others?) have 4 levels in the 3rd dimension
+    if ( length (size (varargout{1}))==3 && length (varargout{1}(1,1,:)) > 3 )
+      varargout{1} = varargout{1}(:,:,1:3);
+    endif
+    break
+  endif
+    
+  ## The next line could be altered from "identify ..." to "gm identify ..."
+  ## If we continue to carry this out with a system call, my guess is that
+  ## more people will have ImageMagick than have GraphicsMagick.  But if
+  ## we want this to work for people who have neither, then the system call
+  ## needs to be scrapped and replaced with a call to a dynamically-linked
+  ## routine that again employs the C++ API to GraphicsMagick.
+  ## Note also the system call to ImageMagick's "convert" farther down.
+  cmd = sprintf ('identify -verbose \"%s\" | grep -e "bit" -e Type', fn);
+  [sys, ident] = system (cmd);
+  if (sys != 0)
+    error ( "imread: error running ImageMagick's 'identify' on %s", fn );
+  endif
+  depth = re_grab ( "([[:digit:]]{1,2})-bit", ident );
+  imtype = re_grab ( "Type: ([[:alpha:]]*)", ident );
+
+  depth = str2num (depth);
+  if ( isempty (depth) || ( pow2 (nextpow2 (depth)) != depth ) )
+    error ( "imread: invalid image depth %s", depth );
+  endif
+
+  if !( strcmp ( imtype, "Bilevel" )   || strcmp ( imtype, "Grayscale" )
+        || strcmp ( imtype, "TrueColor" ) || strcmp ( imtype, "TrueColorMatte" )
+        || strcmp ( imtype, "Palette" ) || strcmp ( imtype, "PaletteMatte" ) )
+    # The 'PaletteMatte' option added by TLS to accomodate ImageMagick
+    # on .png images.  It appears GraphicsMagick returns a different
+    # string, so this will likely be only a temporary change.
+    error ( "imread: unknown image type '%s'", imtype );
+  endif
+
+  switch (imtype)
+    case {"Bilevel"} fmt = "pgm";
+    case {"Grayscale"} fmt = "pgm";
+    case {"TrueColor", "TrueColorMatte", "Palette", "PaletteMatte"}
+      fmt = "ppm";
+  endswitch
+    
+  ## Why are pipes so slow?
+  ##    cmd = sprintf ( "convert -flatten -strip %s %s:-", fn, fmt );
+    
+  tmpf = [tmpnam(), ".", fmt];
+  ##cmd = sprintf ( "convert -flatten -strip +compress '%s' '%s' 2>/dev/null",
+  ##                fn, tmpf );
+  cmd = sprintf ( "convert -strip \"%s\" \"%s\"", fn, tmpf );
+
+  sys = system (cmd);    
+  if (sys != 0)
+    error ("imread: error running ImageMagick's 'convert'");
+    unlink (tmpf);
+  endif
+
+  try
+    fid = fopen ( tmpf, "rb" );
+  catch
+    unlink (tmpf);
+    error ( "imread: could not open temporary file %s", tmpf )
+  end_try_catch
+
+  fgetl (fid); # P5 or P6 (pgm or ppm)
+  [width, height] = sscanf ( fgetl (fid), "%d %d", "C" );
+  fgetl (fid); # ignore max components
+
+  if (depth == 16)
+    ## PGM format has MSB first, i.e. big endian
+    [data, count] = fread ( fid, "uint16", 0, "ieee-be" );
+  else
+    [data, count] = fread ( fid, "uint8" );
+  endif
+    
+  fclose (fid);
+  unlink (tmpf);
+
+  if (any (strcmp ( imtype, {"TrueColor", "TrueColorMatte", ...
+                             "Palette", "PaletteMatte"} ) ) )
+    channels = 3;
+  else
+    channels = 1;
+  endif
+  if (count != width*height*channels)
+    error ( "imread: image data chunk has invalid size %i != %i*%i*%i == %i",
+            count, width, height, channels, width*height*channels );
+  endif
+
+  varargout = {};
+  switch (imtype)
+    case {"Bilevel"} varargout{1} = logical ( reshape (data, width, height)' );
+    case {"Grayscale"} varargout{1} = uint8 ( reshape (data, width, height)' );
+    case {"TrueColor", "TrueColorMatte", "Palette", "PaletteMatte"}
+      varargout{1} = cat(3, reshape ( data(1:3:end), width, height )',
+                         reshape ( data(2:3:end), width, height )',
+                         reshape ( data(3:3:end), width, height )');
+      eval( sprintf( "varargout{1} = uint%d(varargout{1});", depth ) );
+  endswitch
+endfunction
+
+function value = re_grab ( re, str )
+  T = regexp ( str, re, 'tokens' );
+  if ( isempty (T) )
+    value = "";
+  else
+    value = T{1}{1};
+  endif
+endfunction