## Copyright (C) 2008, 2009 Soren Hauberg <hauberg@gmail.com>
##
## 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{info} =} imfinfo (@var{filename})
## @deftypefnx{Function File} {@var{info} =} imfinfo (@var{url})
## Read image information from a file.
##
## @code{imfinfo} returns a structure containing information about the image
## stored in the file @var{filename}. The output structure contains the
## following fields.
##
## @table @samp
## @item Filename
## The full name of the image file.
## @item FileSize
## Number of bytes of the image on disk
## @item FileModDate
## Date of last modification to the file.
## @item Height
## Image height in pixels.
## @item Width
## Image Width in pixels.
## @item BitDepth
## Number of bits per channel per pixel.
## @item Format
## Image format (e.g. @code{"jpeg"}).
## @item LongFormat
## Long form image format description.
## @item XResolution
## X resolution of the image.
## @item YResolution
## Y resolution of the image.
## @item TotalColors
## Number of unique colors in the image.
## @item TileName
## Tile name.
## @item AnimationDelay
## Time in 1/100ths of a second (0 to 65535) which must expire before displaying
## the next image in an animated sequence.
## @item AnimationIterations
## Number of iterations to loop an animation (e.g. Netscape loop extension) for.
## @item ByteOrder
## Endian option for formats that support it. Is either @code{"little-endian"},
## @code{"big-endian"}, or @code{"undefined"}.
## @item Gamma
## Gamma level of the image. The same color image displayed on two different
## workstations  may  look  different due to differences in the display monitor.
## @item Matte
## @code{true} if the image has transparency.
## @item ModulusDepth
## Image modulus depth (minimum number of bits required to support red/green/blue
## components without loss of accuracy).
## @item Quality
## JPEG/MIFF/PNG compression level.
## @item QuantizeColors
## Preferred number of colors in the image.
## @item ResolutionUnits
## Units of image resolution. Is either @code{"pixels per inch"},
## @code{"pixels per centimeter"}, or @code{"undefined"}.
## @item ColorType
## Image type. Is either @code{"grayscale"}, @code{"indexed"}, @code{"truecolor"},
## or @code{"undefined"}.
## @item View
## FlashPix viewing parameters.
## @end table
##
## @seealso{imread, imwrite}
## @end deftypefn

function info = imfinfo (filename)

  if (nargin < 1)
    print_usage ();
  endif

  if (!ischar (filename))
    error ("imfinfo: filename must be a string");
  endif

  filename = tilde_expand (filename);

  delete_file = false;

  unwind_protect

    fn = file_in_path (IMAGE_PATH, filename);

    if (isempty (fn))

      ## Couldn't find file. See if it's an URL.

      tmp = tmpnam ();

      [fn, status, msg] = urlwrite (filename, tmp);

      if (! status)
	error ("imfinfo: cannot find %s", filename);
      endif

      if (! isempty (fn))
	delete_file = true;
      endif

    endif

    [statinfo, err, msg] = stat (fn);
    if (err != 0)
      error ("imfinfo: error reading '%s': %s", fn, msg);
    endif

    time_stamp = strftime ("%e-%b-%Y %H:%M:%S", localtime (statinfo.mtime));
  
    info = __magick_finfo__ (fn);
    info.FileModDate = time_stamp;

  unwind_protect_cleanup

    if (delete_file)
      unlink (fn);
    endif

  end_unwind_protect

endfunction