popsu-d7/sites/all/modules/imagecache_actions/autorotate/imagecache_autorotate.module

<?php
/**
 * @file
 * Autorotate image based on EXIF Orientation tag.
 * http://sylvana.net/jpegcrop/exif_orientation.html
 *
 * This mini-module contributed by jonathan_hunt http://drupal.org/user/28976
 * September 1, 2009
 *
 * Tweaked by dman to add documentation
 */

/* In Adobe PNGs and TIFF, this information MAY be present in the XMP
 * metadata like so:

 <x:xmpmeta xmlns:x="adobe:ns:meta/">
 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
 <rdf:Description rdf:about="" xmlns:tiff="http://ns.adobe.com/tiff/1.0/">
 <tiff:Orientation>6</tiff:Orientation>
 </rdf:Description>
 </rdf:RDF>
 </x:xmpmeta>

 */

function imagecache_autorotate_image_effect_info() {
  $effects = array();

  $effects['imagecache_autorotate'] = array(
    'label' => t('Autorotate'),
    'help' => t('Add autorotate image based on EXIF Orientation.'),
    'effect callback' => 'imagecache_autorotate_image',
    'dimensions callback' => 'imagecache_autorotate_dimensions',
  );

  return $effects;
}

/**
 * @todo: This form is no longer needed nor defined in the hook above. If this
 * information still needs to be displayed it should probably be moved to help.
 */
function imagecache_autorotate_form() {
  $form = array();
  $form['help'] = array(
    '#type' => 'markup',
    '#value' => "<p>
      <b>There are no user-configurable options for this process.</b>
      </p><p>
      Certain cameras can embed <em>orientation</em> information into image
      files when they save them. This information is embedded in an EXIF tag
      and can be used to rotate images to their correct position for display.
      </p><p>
      <em>Not all cameras or images contain this information.</em>
      This process is only useful for those that do.
      </p><p>
      The expected/supported values are
      <br/><strong>Tag</strong>: <code>0x0112  Orientation</code>
      </p>
      <ul>
      <li>1 = Horizontal (normal)</li>
      <li>3 = Rotate 180</li>
      <li>6 = Rotate 90 CW</li>
      <li>8 = Rotate 270 CW</li>
      </ul>
      <p>
      <a href='http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/EXIF.html'>
EXIF Reference</a>
      </p>
    ",
  );
  return $form;
}

/**
 * Autorotate image based on EXIF Orientation tag.
 *
 * See code at
 * http://sylvana.net/jpegcrop/exif_orientation.html
 *
 * and reference at
 * http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/EXIF.html
 *
 * @todo:
 * Add horizontal and vertical flips etc.
 * Need to create sample set for tests.
 */
function imagecache_autorotate_image($image, $data) {
  // Test to see if EXIF is supported for image type (e.g. not PNG).
  if ($image->info['mime_type'] == 'image/jpeg') {
    if (!function_exists('exif_read_data')) {
      watchdog('image', 'The image %file could not be auto-rotated because the exif_read_data() function is not available in this PHP installation. You probably will have to enable the exif extension.', array('%file' => $image->source));
      return FALSE;
    }
    $exif = exif_read_data(drupal_realpath($image->source));
    if (isset($exif['Orientation'])) {
      switch ($exif['Orientation']) {
        case 3:
          $degrees = 180;
          break;
        case 6:
          $degrees = 90;
          break;
        case 8:
          $degrees = 270;
          break;
        default:
          $degrees = 0;
      }
      if ($degrees != 0) {
        $org_width = $image->info['width'];
        $org_height = $image->info['height'];
        image_rotate($image, $degrees);
        if (($degrees === 90 || $degrees === 270) && $image->info['width'] === $org_width) {
          // The toolkit failed to alter the dimensions (imagemagick currently
          // fails to do so). So we do it ourselves.
          $image->info['width'] = $org_height;
          $image->info['height'] = $org_width;
        }
      }
    }
  }
  else if ($image->source === 'modules/image/sample.png' && !function_exists('exif_read_data')) {
    // Issue a warning if we are in the admin screen and the exif extension is
    // not enabled.
    drupal_set_message(t('The exif_read_data() function is not available in this PHP installation. You probably will have to enable the exif extension.'), 'warning');
  }
  return TRUE;
}

/**
 * Image dimensions callback; Auto-rotate.
 *
 * @param array $dimensions
 *   An array with the dimensions (in pixels) to be modified.
 * @param array $data
 *   An array of parameters for the autorotate effect (empty for this effect).
*/
function imagecache_autorotate_dimensions(array &$dimensions, array $data) {
  // We can only know the resulting dimensions if both dimensions are equal.
  // Otherwise we need to inspect the image itself, which is not passed in here.
  // (this callback was introduced to enhance performance by not accessing the
  // image file when rendering the width and height attributes of the html img
  // tag).
  if ($dimensions['width'] !== $dimensions['height']) {
    $dimensions['width'] = $dimensions['height'] = NULL;
  }
}