###########################################################################
#
# AdvImagePlugin.pm -- extends the standard ImagePlugin with feature
#                      extraction using the OpenSIFT program.  SIFT, in
#                      turn requires the OpenCV libraries.
#
# A component of the Greenstone digital library software from the New
# Zealand Digital Library Project at the University of Waikato, New
# Zealand.
#
# Copyright (C) 1999 New Zealand Digital Library Project
#
# 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., 675 Mass Ave, Cambridge, MA 02139, USA.
#
###########################################################################

package AdvImagePlugin;

use ImagePlugin;

use strict;
no strict 'refs'; # allow filehandles to be variables and viceversa
no strict 'subs';

use gsprintf 'gsprintf';

sub BEGIN {
    @AdvImagePlugin::ISA = ('ImagePlugin');
}

my $arguments =
    [ { 'name' => "process_exp",
	'desc' => "{BasePlugin.process_exp}",
	'type' => "regexp",
	'deft' => &get_default_process_exp(),
	'reqd' => "no" },
      ];

my $options = { 'name'     => "AdvImagePlugin",
		'desc'     => "{ImagePlugin.desc}",
		'abstract' => "no",
		'inherits' => "yes",
		'args'     => $arguments };


## @function
#
sub new {
    my ($class) = shift (@_);
    my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
    push(@$pluginlist, $class);
    push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
    push(@{$hashArgOptLists->{"OptList"}},$options);
    my $self = new ImagePlugin($pluginlist, $inputargs, $hashArgOptLists);
    $self->{'sift_available'} = 0;
    return bless $self, $class;
}
##


## @function
#
sub init {
  my $self = shift (@_);
  my ($verbosity, $outhandle, $failhandle) = @_;
  $self->SUPER::init(@_);
  # Test that OpenSIFT is available... otherwise nothing else is going to work
  my $sift_version = `siftfeat -h 2>&1`;
  if ($sift_version =~ /siftfeat version \d+\.\d+\.\d+/)
  {
    $self->{'sift_available'} = 1;
  }
}
##


## @function
# - for now we'll restrict to JPGs because I know OpenSIFT likes them
sub get_default_process_exp {
  my $self = shift (@_);
  return q^(?i)\.(jpe?g)$^;
}
##


## @function
# do plugin specific processing of doc_obj
sub process {
  my $self = shift (@_);
  my ($pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli) = @_;

  $self->SUPER::process($pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli);

  my $outhandle = $self->{'outhandle'};
  my ($filename_full_path, $filename_no_path) = &util::get_full_filenames($base_dir, $file);


  if ($self->{'sift_available'} == 1)
  {
    # we call SIFT on the image, and then read the Oxford formatted features
    # from STDOUT
    # any other messages on STDERR are sent to nullsville
    my $sift_command = 'siftfeat -x "' . $filename_full_path . '" 2>/dev/null';
    my $oxfd_features = `$sift_command`;
    $doc_obj->add_metadata ($doc_obj->get_top_section(), "SIFTOXFDFeatures", $oxfd_features);
  }
  else
  {
    print STDERR 'Warning! SIFT features cannot be extracted: ' . $file . "\n";
  }
  return 1;
}

1;