islandora/plugins/fedora_imageapi.module

<?php



function fedora_imageapi_menu() {
  $items = array();
  $items['fedora/imageapi'] = array(
    'title' => t('Image manipulation functions'),
    'page callback' => 'fedora_repository_image_manip',
    'type' => MENU_CALLBACK,
    'access arguments' => array('view fedora collection'),
  );
  return $items;
}

/**
 * Call out to the Drupal ImageAPI module and return the resulting image as a stream.
 *
 * @param string $pid
 * @param string $dsid
 * @param string $op
 * @param string $params
 */
function fedora_repository_image_manip($pid = '', $dsid = '', $op = '', $params = '') {
  module_load_include('inc', 'Fedora_Repository', 'ObjectHelper');
  module_load_include('module', 'imageapi');
  $obj = new ObjectHelper();
  $mimetype = $obj->getMimeType($pid, $dsid);
  $ext = substr(strstr($mimetype, '/'), 1);
  $op = (!empty($_GET['op']) ? $_GET['op'] : '');
  $safe_pid = str_replace(':', '_', $pid);

  $cache_key = 'fedora_repository_image_manip_' . md5($safe_pid . '_' . $dsid . '_' . $ext . '_' . $op . (isset($_GET['width']) ? '_' . $_GET['width'] : '') . (isset($_GET['height']) ? '_' . $_GET['height'] : ''));
  if (($file = cache_get($cache_key)) === 0) {
    //added the slash as sys_get_temp_dir in linux does not seem to include the slash
    $tmp_file_name = sys_get_temp_dir() . '/' . $safe_pid . '_' . $dsid . '.' . $ext;
    $handle = fopen($tmp_file_name, "w");
    $numbytes = fwrite($handle, $obj->getStream($pid, $dsid));
    fclose($handle);
    if ($numbytes == 0) {
      return;
    }


    $image = imageapi_image_open($tmp_file_name);

    switch ($op) {
      case 'scale':
        if (!empty($_GET['height']) || !empty($_GET['width'])) {
          imageapi_image_scale($image, $_GET['width'], $_GET['height']);
        }
      case 'centerscale':
        if (!empty($_GET['height']) && !empty($_GET['width'])) {
          imageapi_image_scale_and_crop($image, $_GET['width'], $_GET['height']);
        }
    }
    imageapi_image_close($image);
    $file = file_get_contents($tmp_file_name);
    cache_set($cache_key, $file, 'cache', time() + variable_get('fedora_image_blocks_cache_time', 3600));
    file_delete($tmp_file_name);
  }
  else {
    $file = $file->data;
  }


  header("Content-type: $mimetype");
  header('Content-Disposition: attachment; filename="' . $dsid . '.' . $ext . '"');
  echo $file;


//  return "$numbytes bytes written to ".sys_get_temp_dir()."$pid_$dsid.$ext\n";
}

/**
 * Implementation of hook_form_alter
 *
 * @param unknown_type $form
 * @param unknown_type $form_state
 * @param unknown_type $form_id
 */
/*
  function fedora_imageapi_form_alter( &$form, $form_state, $form_id) {

  switch ( $form_id ) {
  case 'fedora_repository_admin':

  $fedora_base_url = $form['fedora_base_url']['#default_value'];

  $fedora_server_url = substr($fedora_base_url,0,strpos($fedora_base_url,'/',7));
  // Add the Djatoka server location. Set it to default to the same server as fedora.
  $form['djatoka_server_url'] = array (
  '#type' => 'textfield',
  '#title' => '<h3>'.t('Fedora Image API Module').'</h3><br />'.t('aDORe Djatoka image server resolver URL'),
  '#default_value' => variable_get('djatoka_server_url', $fedora_server_url.'/adore-djatoka/resolver' ),
  '#description' => t('The location of your <a href="http://african.lanl.gov/aDORe/projects/djatoka/" title="aDORe Djatoka Home Page">aDORe Djatoka</a> image server, if you have one installed.'),
  '#weight' => 1,
  );
  $form['openlayers_server_url'] = array(
  '#type' => 'textfield',
  '#title' => t('OpenLayers servlet URL'),
  '#default_value' => variable_get('openlayers_server_url', $fedora_server_url.'/islandora/OpenLayers'),
  '#description' => t('URL of your installation of the <a href="http://openlayers.org/">OpenLayers</a> servlet, if you have one.'),
  '#weight' => 1,
  );
  $form['buttons']['#weight'] = 2;
  break;
  }
  }

  function show_openlayers_viewer() {
  $output = 'Hi.';

  return $output;
  }
 */