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   1  <?php
   2  /**
   3   * File contains all the administration image manipulation functions.
   4   *
   5   * @package WordPress
   6   * @subpackage Administration
   7   */
   8  
   9  /**
  10   * Create a thumbnail from an Image given a maximum side size.
  11   *
  12   * This function can handle most image file formats which PHP supports. If PHP
  13   * does not have the functionality to save in a file of the same format, the
  14   * thumbnail will be created as a jpeg.
  15   *
  16   * @since 1.2.0
  17   *
  18   * @param mixed $file Filename of the original image, Or attachment id.
  19   * @param int $max_side Maximum length of a single side for the thumbnail.
  20   * @return string Thumbnail path on success, Error string on failure.
  21   */
  22  function wp_create_thumbnail( $file, $max_side, $deprecated = '' ) {
  23      $thumbpath = image_resize( $file, $max_side, $max_side );
  24      return apply_filters( 'wp_create_thumbnail', $thumbpath );
  25  }
  26  
  27  /**
  28   * Crop an Image to a given size.
  29   *
  30   * @since 2.1.0
  31   *
  32   * @param string|int $src_file The source file or Attachment ID.
  33   * @param int $src_x The start x position to crop from.
  34   * @param int $src_y The start y position to crop from.
  35   * @param int $src_w The width to crop.
  36   * @param int $src_h The height to crop.
  37   * @param int $dst_w The destination width.
  38   * @param int $dst_h The destination height.
  39   * @param int $src_abs Optional. If the source crop points are absolute.
  40   * @param string $dst_file Optional. The destination file to write to.
  41   * @return string New filepath on success, String error message on failure.
  42   */
  43  function wp_crop_image( $src_file, $src_x, $src_y, $src_w, $src_h, $dst_w, $dst_h, $src_abs = false, $dst_file = false ) {
  44      if ( is_numeric( $src_file ) ) // Handle int as attachment ID
  45          $src_file = get_attached_file( $src_file );
  46  
  47      $src = wp_load_image( $src_file );
  48  
  49      if ( !is_resource( $src ))
  50          return $src;
  51  
  52      $dst = wp_imagecreatetruecolor( $dst_w, $dst_h );
  53  
  54      if ( $src_abs ) {
  55          $src_w -= $src_x;
  56          $src_h -= $src_y;
  57      }
  58  
  59      if (function_exists('imageantialias'))
  60          imageantialias( $dst, true );
  61  
  62      imagecopyresampled( $dst, $src, 0, 0, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h );
  63  
  64      imagedestroy( $src ); // Free up memory
  65  
  66      if ( ! $dst_file )
  67          $dst_file = str_replace( basename( $src_file ), 'cropped-' . basename( $src_file ), $src_file );
  68  
  69      $dst_file = preg_replace( '/\\.[^\\.]+$/', '.jpg', $dst_file );
  70  
  71      if ( imagejpeg( $dst, $dst_file, apply_filters( 'jpeg_quality', 90, 'wp_crop_image' ) ) )
  72          return $dst_file;
  73      else
  74          return false;
  75  }
  76  
  77  /**
  78   * Generate post thumbnail attachment meta data.
  79   *
  80   * @since 2.1.0
  81   *
  82   * @param int $attachment_id Attachment Id to process.
  83   * @param string $file Filepath of the Attached image.
  84   * @return mixed Metadata for attachment.
  85   */
  86  function wp_generate_attachment_metadata( $attachment_id, $file ) {
  87      $attachment = get_post( $attachment_id );
  88  
  89      $metadata = array();
  90      if ( preg_match('!^image/!', get_post_mime_type( $attachment )) && file_is_displayable_image($file) ) {
  91          $imagesize = getimagesize( $file );
  92          $metadata['width'] = $imagesize[0];
  93          $metadata['height'] = $imagesize[1];
  94          list($uwidth, $uheight) = wp_shrink_dimensions($metadata['width'], $metadata['height']);
  95          $metadata['hwstring_small'] = "height='$uheight' width='$uwidth'";
  96  
  97          // Make the file path relative to the upload dir
  98          $metadata['file'] = _wp_relative_upload_path($file);
  99  
 100          // make thumbnails and other intermediate sizes
 101          global $_wp_additional_image_sizes;
 102          $temp_sizes = array('thumbnail', 'medium', 'large'); // Standard sizes
 103          if ( isset( $_wp_additional_image_sizes ) && count( $_wp_additional_image_sizes ) )
 104              $temp_sizes = array_merge( $temp_sizes, array_keys( $_wp_additional_image_sizes ) );
 105  
 106          $temp_sizes = apply_filters( 'intermediate_image_sizes', $temp_sizes );
 107  
 108          foreach ( $temp_sizes as $s ) {
 109              $sizes[$s] = array( 'width' => '', 'height' => '', 'crop' => FALSE );
 110              if ( isset( $_wp_additional_image_sizes[$s]['width'] ) )
 111                  $sizes[$s]['width'] = intval( $_wp_additional_image_sizes[$s]['width'] ); // For theme-added sizes
 112              else
 113                  $sizes[$s]['width'] = get_option( "{$s}_size_w" ); // For default sizes set in options
 114              if ( isset( $_wp_additional_image_sizes[$s]['height'] ) )
 115                  $sizes[$s]['height'] = intval( $_wp_additional_image_sizes[$s]['height'] ); // For theme-added sizes
 116              else
 117                  $sizes[$s]['height'] = get_option( "{$s}_size_h" ); // For default sizes set in options
 118              if ( isset( $_wp_additional_image_sizes[$s]['crop'] ) )
 119                  $sizes[$s]['crop'] = intval( $_wp_additional_image_sizes[$s]['crop'] ); // For theme-added sizes
 120              else
 121                  $sizes[$s]['crop'] = get_option( "{$s}_crop" ); // For default sizes set in options
 122          }
 123  
 124          $sizes = apply_filters( 'intermediate_image_sizes_advanced', $sizes );
 125  
 126          foreach ($sizes as $size => $size_data ) {
 127              $resized = image_make_intermediate_size( $file, $size_data['width'], $size_data['height'], $size_data['crop'] );
 128              if ( $resized )
 129                  $metadata['sizes'][$size] = $resized;
 130          }
 131  
 132          // fetch additional metadata from exif/iptc
 133          $image_meta = wp_read_image_metadata( $file );
 134          if ( $image_meta )
 135              $metadata['image_meta'] = $image_meta;
 136  
 137      }
 138  
 139      return apply_filters( 'wp_generate_attachment_metadata', $metadata, $attachment_id );
 140  }
 141  
 142  /**
 143   * Load an image from a string, if PHP supports it.
 144   *
 145   * @since 2.1.0
 146   *
 147   * @param string $file Filename of the image to load.
 148   * @return resource The resulting image resource on success, Error string on failure.
 149   */
 150  function wp_load_image( $file ) {
 151      if ( is_numeric( $file ) )
 152          $file = get_attached_file( $file );
 153  
 154      if ( ! file_exists( $file ) )
 155          return sprintf(__('File &#8220;%s&#8221; doesn&#8217;t exist?'), $file);
 156  
 157      if ( ! function_exists('imagecreatefromstring') )
 158          return __('The GD image library is not installed.');
 159  
 160      // Set artificially high because GD uses uncompressed images in memory
 161      @ini_set('memory_limit', '256M');
 162      $image = imagecreatefromstring( file_get_contents( $file ) );
 163  
 164      if ( !is_resource( $image ) )
 165          return sprintf(__('File &#8220;%s&#8221; is not an image.'), $file);
 166  
 167      return $image;
 168  }
 169  
 170  /**
 171   * Calculated the new dimentions for a downsampled image.
 172   *
 173   * @since 2.0.0
 174   * @see wp_shrink_dimensions()
 175   *
 176   * @param int $width Current width of the image
 177   * @param int $height Current height of the image
 178   * @return mixed Array(height,width) of shrunk dimensions.
 179   */
 180  function get_udims( $width, $height) {
 181      return wp_shrink_dimensions( $width, $height );
 182  }
 183  
 184  /**
 185   * Calculates the new dimentions for a downsampled image.
 186   *
 187   * @since 2.0.0
 188   * @see wp_constrain_dimensions()
 189   *
 190   * @param int $width Current width of the image
 191   * @param int $height Current height of the image
 192   * @param int $wmax Maximum wanted width
 193   * @param int $hmax Maximum wanted height
 194   * @return mixed Array(height,width) of shrunk dimensions.
 195   */
 196  function wp_shrink_dimensions( $width, $height, $wmax = 128, $hmax = 96 ) {
 197      return wp_constrain_dimensions( $width, $height, $wmax, $hmax );
 198  }
 199  
 200  /**
 201   * Convert a fraction string to a decimal.
 202   *
 203   * @since 2.5.0
 204   *
 205   * @param string $str
 206   * @return int|float
 207   */
 208  function wp_exif_frac2dec($str) {
 209      @list( $n, $d ) = explode( '/', $str );
 210      if ( !empty($d) )
 211          return $n / $d;
 212      return $str;
 213  }
 214  
 215  /**
 216   * Convert the exif date format to a unix timestamp.
 217   *
 218   * @since 2.5.0
 219   *
 220   * @param string $str
 221   * @return int
 222   */
 223  function wp_exif_date2ts($str) {
 224      @list( $date, $time ) = explode( ' ', trim($str) );
 225      @list( $y, $m, $d ) = explode( ':', $date );
 226  
 227      return strtotime( "{$y}-{$m}-{$d} {$time}" );
 228  }
 229  
 230  /**
 231   * Get extended image metadata, exif or iptc as available.
 232   *
 233   * Retrieves the EXIF metadata aperture, credit, camera, caption, copyright, iso
 234   * created_timestamp, focal_length, shutter_speed, and title.
 235   *
 236   * The IPTC metadata that is retrieved is APP13, credit, byline, created date
 237   * and time, caption, copyright, and title. Also includes FNumber, Model,
 238   * DateTimeDigitized, FocalLength, ISOSpeedRatings, and ExposureTime.
 239   *
 240   * @todo Try other exif libraries if available.
 241   * @since 2.5.0
 242   *
 243   * @param string $file
 244   * @return bool|array False on failure. Image metadata array on success.
 245   */
 246  function wp_read_image_metadata( $file ) {
 247      if ( !file_exists( $file ) )
 248          return false;
 249  
 250      list(,,$sourceImageType) = getimagesize( $file );
 251  
 252      // exif contains a bunch of data we'll probably never need formatted in ways
 253      // that are difficult to use. We'll normalize it and just extract the fields
 254      // that are likely to be useful.  Fractions and numbers are converted to
 255      // floats, dates to unix timestamps, and everything else to strings.
 256      $meta = array(
 257          'aperture' => 0,
 258          'credit' => '',
 259          'camera' => '',
 260          'caption' => '',
 261          'created_timestamp' => 0,
 262          'copyright' => '',
 263          'focal_length' => 0,
 264          'iso' => 0,
 265          'shutter_speed' => 0,
 266          'title' => '',
 267      );
 268  
 269      // read iptc first, since it might contain data not available in exif such
 270      // as caption, description etc
 271      if ( is_callable('iptcparse') ) {
 272          getimagesize($file, $info);
 273          if ( !empty($info['APP13']) ) {
 274              $iptc = iptcparse($info['APP13']);
 275              if ( !empty($iptc['2#110'][0]) ) // credit
 276                  $meta['credit'] = utf8_encode(trim($iptc['2#110'][0]));
 277              elseif ( !empty($iptc['2#080'][0]) ) // byline
 278                  $meta['credit'] = utf8_encode(trim($iptc['2#080'][0]));
 279              if ( !empty($iptc['2#055'][0]) and !empty($iptc['2#060'][0]) ) // created date and time
 280                  $meta['created_timestamp'] = strtotime($iptc['2#055'][0] . ' ' . $iptc['2#060'][0]);
 281              if ( !empty($iptc['2#120'][0]) ) // caption
 282                  $meta['caption'] = utf8_encode(trim($iptc['2#120'][0]));
 283              if ( !empty($iptc['2#116'][0]) ) // copyright
 284                  $meta['copyright'] = utf8_encode(trim($iptc['2#116'][0]));
 285              if ( !empty($iptc['2#005'][0]) ) // title
 286                  $meta['title'] = utf8_encode(trim($iptc['2#005'][0]));
 287           }
 288      }
 289  
 290      // fetch additional info from exif if available
 291      if ( is_callable('exif_read_data') && in_array($sourceImageType, apply_filters('wp_read_image_metadata_types', array(IMAGETYPE_JPEG, IMAGETYPE_TIFF_II, IMAGETYPE_TIFF_MM)) ) ) {
 292          $exif = @exif_read_data( $file );
 293          if (!empty($exif['FNumber']))
 294              $meta['aperture'] = round( wp_exif_frac2dec( $exif['FNumber'] ), 2 );
 295          if (!empty($exif['Model']))
 296              $meta['camera'] = trim( $exif['Model'] );
 297          if (!empty($exif['DateTimeDigitized']))
 298              $meta['created_timestamp'] = wp_exif_date2ts($exif['DateTimeDigitized']);
 299          if (!empty($exif['FocalLength']))
 300              $meta['focal_length'] = wp_exif_frac2dec( $exif['FocalLength'] );
 301          if (!empty($exif['ISOSpeedRatings']))
 302              $meta['iso'] = $exif['ISOSpeedRatings'];
 303          if (!empty($exif['ExposureTime']))
 304              $meta['shutter_speed'] = wp_exif_frac2dec( $exif['ExposureTime'] );
 305      }
 306  
 307      return apply_filters( 'wp_read_image_metadata', $meta, $file, $sourceImageType );
 308  
 309  }
 310  
 311  /**
 312   * Validate that file is an image.
 313   *
 314   * @since 2.5.0
 315   *
 316   * @param string $path File path to test if valid image.
 317   * @return bool True if valid image, false if not valid image.
 318   */
 319  function file_is_valid_image($path) {
 320      $size = @getimagesize($path);
 321      return !empty($size);
 322  }
 323  
 324  /**
 325   * Validate that file is suitable for displaying within a web page.
 326   *
 327   * @since 2.5.0
 328   * @uses apply_filters() Calls 'file_is_displayable_image' on $result and $path.
 329   *
 330   * @param string $path File path to test.
 331   * @return bool True if suitable, false if not suitable.
 332   */
 333  function file_is_displayable_image($path) {
 334      $info = @getimagesize($path);
 335      if ( empty($info) )
 336          $result = false;
 337      elseif ( !in_array($info[2], array(IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG)) )    // only gif, jpeg and png images can reliably be displayed
 338          $result = false;
 339      else
 340          $result = true;
 341  
 342      return apply_filters('file_is_displayable_image', $result, $path);
 343  }