includes/media/Bitmap.php

   1 <?php
   2 /**
   3  * Generic handler for bitmap images
   4  *
   5  * @file
   6  * @ingroup Media
   7  */
   8
   9 /**
  10  * Generic handler for bitmap images
  11  *
  12  * @ingroup Media
  13  */
  14 class BitmapHandler extends ImageHandler {
  15         function normaliseParams( $image, &$params ) {
  16                 global $wgMaxImageArea;
  17                 if ( !parent::normaliseParams( $image, $params ) ) {
  18                         return false;
  19                 }
  20
  21                 $mimeType = $image->getMimeType();
  22                 $srcWidth = $image->getWidth( $params['page'] );
  23                 $srcHeight = $image->getHeight( $params['page'] );
  24
  25                 # Don't make an image bigger than the source
  26                 $params['physicalWidth'] = $params['width'];
  27                 $params['physicalHeight'] = $params['height'];
  28
  29                 if ( $params['physicalWidth'] >= $srcWidth ) {
  30                         $params['physicalWidth'] = $srcWidth;
  31                         $params['physicalHeight'] = $srcHeight;
  32                         # Skip scaling limit checks if no scaling is required
  33                         if ( !$image->mustRender() )
  34                                 return true;
  35                 }
  36
  37                 # Don't thumbnail an image so big that it will fill hard drives and send servers into swap
  38                 # JPEG has the handy property of allowing thumbnailing without full decompression, so we make
  39                 # an exception for it.
  40                 # FIXME: This actually only applies to ImageMagick
  41                 if ( $mimeType !== 'image/jpeg' &&
  42                         $srcWidth * $srcHeight > $wgMaxImageArea )
  43                 {
  44                         return false;
  45                 }
  46
  47                 return true;
  48         }
  49
  50
  51         // Function that returns the number of pixels to be thumbnailed.
  52         // Intended for animated GIFs to multiply by the number of frames.
  53         function getImageArea( $image, $width, $height ) {
  54                 return $width * $height;
  55         }
  56
  57         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
  58                 global $wgUseImageMagick;
  59                 global $wgCustomConvertCommand, $wgUseImageResize;
  60
  61                 if ( !$this->normaliseParams( $image, $params ) ) {
  62                         return new TransformParameterError( $params );
  63                 }
  64                 # Create a parameter array to pass to the scaler
  65                 $scalerParams = array(
  66                         # The size to which the image will be resized
  67                         'physicalWidth' => $params['physicalWidth'],
  68                         'physicalHeight' => $params['physicalHeight'],
  69                         'physicalDimensions' => "{$params['physicalWidth']}x{$params['physicalHeight']}",
  70                         # The size of the image on the page
  71                         'clientWidth' => $params['width'],
  72                         'clientHeight' => $params['height'],
  73                         # Comment as will be added to the EXIF of the thumbnail
  74                         'comment' => isset( $params['descriptionUrl'] ) ?
  75                                 "File source: {$params['descriptionUrl']}" : '',
  76                         # Properties of the original image
  77                         'srcWidth' => $image->getWidth(),
  78                         'srcHeight' => $image->getHeight(),
  79                         'mimeType' => $image->getMimeType(),
  80                         'srcPath' => $image->getPath(),
  81                         'dstPath' => $dstPath,
  82                 );
  83
  84                 wfDebug( __METHOD__ . ": creating {$scalerParams['physicalDimensions']} thumbnail at $dstPath\n" );
  85
  86                 if ( !$image->mustRender() &&
  87                                 $scalerParams['physicalWidth'] == $scalerParams['srcWidth']
  88                                 && $scalerParams['physicalHeight'] == $scalerParams['srcHeight'] ) {
  89
  90                         # normaliseParams (or the user) wants us to return the unscaled image
  91                         wfDebug( __METHOD__ . ": returning unscaled image\n" );
  92                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
  93                 }
  94
  95                 # Determine scaler type
  96                 if ( !$dstPath ) {
  97                         # No output path available, client side scaling only
  98                         $scaler = 'client';
  99                 } elseif ( !$wgUseImageResize ) {
 100                         $scaler = 'client';
 101                 } elseif ( $wgUseImageMagick ) {
 102                         $scaler = 'im';
 103                 } elseif ( $wgCustomConvertCommand ) {
 104                         $scaler = 'custom';
 105                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
 106                         $scaler = 'gd';
 107                 } else {
 108                         $scaler = 'client';
 109                 }
 110                 wfDebug( __METHOD__ . ": scaler $scaler\n" );
 111
 112                 if ( $scaler == 'client' ) {
 113                         # Client-side image scaling, use the source URL
 114                         # Using the destination URL in a TRANSFORM_LATER request would be incorrect
 115                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 116                 }
 117
 118                 if ( $flags & self::TRANSFORM_LATER ) {
 119                         wfDebug( __METHOD__ . ": Transforming later per flags.\n" );
 120                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 121                                 $scalerParams['clientHeight'], $dstPath );
 122                 }
 123
 124                 # Try to make a target path for the thumbnail
 125                 if ( !wfMkdirParents( dirname( $dstPath ) ) ) {
 126                         wfDebug( __METHOD__ . ": Unable to create thumbnail destination directory, falling back to client scaling\n" );
 127                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 128                 }
 129
 130                 switch ( $scaler ) {
 131                         case 'im':
 132                                 $err = $this->transformImageMagick( $image, $scalerParams );
 133                                 break;
 134                         case 'custom':
 135                                 $err = $this->transformCustom( $image, $scalerParams );
 136                                 break;
 137                         case 'gd':
 138                         default:
 139                                 $err = $this->transformGd( $image, $scalerParams );
 140                                 break;
 141                 }
 142
 143                 # Remove the file if a zero-byte thumbnail was created, or if there was an error
 144                 $removed = $this->removeBadFile( $dstPath, (bool)$err );
 145                 if ( $err ) {
 146                         # transform returned MediaTransforError
 147                         return $err;
 148                 } elseif ( $removed ) {
 149                         # Thumbnail was zero-byte and had to be removed
 150                         return new MediaTransformError( 'thumbnail_error',
 151                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'] );
 152                 } else {
 153                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 154                                 $scalerParams['clientHeight'], $dstPath );
 155                 }
 156         }
 157
 158         /**
 159          * Get a ThumbnailImage that respresents an image that will be scaled
 160          * client side
 161          *
 162          * @param $image File File associated with this thumbnail
 163          * @param $params array Array with scaler params
 164          * @return ThumbnailImage
 165          */
 166         protected function getClientScalingThumbnailImage( $image, $params ) {
 167                 return new ThumbnailImage( $image, $image->getURL(),
 168                                 $params['clientWidth'], $params['clientHeight'], $params['srcPath'] );
 169         }
 170
 171         /**
 172          * Transform an image using ImageMagick
 173          *
 174          * @param $image File File associated with this thumbnail
 175          * @param $params array Array with scaler params
 176          *
 177          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 178          */
 179         protected function transformImageMagick( $image, $params ) {
 180                 # use ImageMagick
 181                 global $wgSharpenReductionThreshold, $wgSharpenParameter,
 182                         $wgMaxAnimatedGifArea,
 183                         $wgImageMagickTempDir, $wgImageMagickConvertCommand;
 184
 185                 $quality = '';
 186                 $sharpen = '';
 187                 $scene = false;
 188                 $animation_pre = '';
 189                 $animation_post = '';
 190                 $decoderHint = '';
 191                 if ( $params['mimeType'] == 'image/jpeg' ) {
 192                         $quality = "-quality 80"; // 80%
 193                         # Sharpening, see bug 6193
 194                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 195                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 196                                         < $wgSharpenReductionThreshold ) {
 197                                 $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 198                         }
 199                         // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 200                         $decoderHint = "-define jpeg:size={$params['physicalDimensions']}";
 201
 202                 } elseif ( $params['mimeType'] == 'image/png' ) {
 203                         $quality = "-quality 95"; // zlib 9, adaptive filtering
 204
 205                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 206                         if ( $this->getImageArea( $image, $params['srcWidth'],
 207                                         $params['srcHeight'] ) > $wgMaxAnimatedGifArea ) {
 208                                 // Extract initial frame only; we're so big it'll
 209                                 // be a total drag. :P
 210                                 $scene = 0;
 211
 212                         } elseif ( $this->isAnimatedImage( $image ) ) {
 213                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 214                                 $animation_pre = '-coalesce';
 215                                 // We optimize the output, but -optimize is broken,
 216                                 // use optimizeTransparency instead (bug 11822)
 217                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 218                                         $animation_post = '-fuzz 5% -layers optimizeTransparency +map';
 219                                 }
 220                         }
 221                 }
 222
 223                 // Use one thread only, to avoid deadlock bugs on OOM
 224                 $env = array( 'OMP_NUM_THREADS' => 1 );
 225                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 226                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 227                 }
 228
 229                 $cmd  =
 230                         wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 231                         // Specify white background color, will be used for transparent images
 232                         // in Internet Explorer/Windows instead of default black.
 233                         " {$quality} -background white" .
 234                         " {$decoderHint} " .
 235                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 236                         " {$animation_pre}" .
 237                         // For the -thumbnail option a "!" is needed to force exact size,
 238                         // or ImageMagick may decide your ratio is wrong and slice off
 239                         // a pixel.
 240                         " -thumbnail " . wfEscapeShellArg( "{$params['physicalDimensions']}!" ) .
 241                         // Add the source url as a comment to the thumb.
 242                         " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) ) .
 243                         " -depth 8 $sharpen" .
 244                         " {$animation_post} " .
 245                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) ) . " 2>&1";
 246
 247                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 248                 wfProfileIn( 'convert' );
 249                 $retval = 0;
 250                 $err = wfShellExec( $cmd, $retval, $env );
 251                 wfProfileOut( 'convert' );
 252
 253                 if ( $retval !== 0 ) {
 254                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 255                         return $this->getMediaTransformError( $params, $err );
 256                 }
 257
 258                 return false; # No error
 259         }
 260
 261         /**
 262          * Transform an image using a custom command
 263          *
 264          * @param $image File File associated with this thumbnail
 265          * @param $params array Array with scaler params
 266          *
 267          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 268          */
 269         protected function transformCustom( $image, $params ) {
 270                 # Use a custom convert command
 271                 global $wgCustomConvertCommand;
 272
 273                 # Variables: %s %d %w %h
 274                 $src = wfEscapeShellArg( $params['srcPath'] );
 275                 $dst = wfEscapeShellArg( $params['dstPath'] );
 276                 $cmd = $wgCustomConvertCommand;
 277                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 278                 $cmd = str_replace( '%h', $params['physicalHeight'],
 279                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 280                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 281                 wfProfileIn( 'convert' );
 282                 $retval = 0;
 283                 $err = wfShellExec( $cmd, $retval );
 284                 wfProfileOut( 'convert' );
 285
 286                 if ( $retval !== 0 ) {
 287                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 288                         return $this->getMediaTransformError( $params, $err );
 289                 }
 290                 return false; # No error
 291         }
 292
 293         /**
 294          * Log an error that occured in an external process
 295          *
 296          * @param $retval int
 297          * @param $err int
 298          * @param $cmd string
 299          */
 300         protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
 301                 wfDebugLog( 'thumbnail',
 302                         sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 303                                         wfHostname(), $retval, trim( $err ), $cmd ) );
 304         }
 305         /**
 306          * Get a MediaTransformError with error 'thumbnail_error'
 307          *
 308          * @param $params array Paramter array as passed to the transform* functions
 309          * @param $errMsg string Error message
 310          * @return MediaTransformError
 311          */
 312         protected function getMediaTransformError( $params, $errMsg ) {
 313                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 314                                         $params['clientHeight'], $errMsg );
 315         }
 316
 317         /**
 318          * Transform an image using the built in GD library
 319          *
 320          * @param $image File File associated with this thumbnail
 321          * @param $params array Array with scaler params
 322          *
 323          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 324          */
 325         protected function transformGd( $image, $params ) {
 326                 # Use PHP's builtin GD library functions.
 327                 #
 328                 # First find out what kind of file this is, and select the correct
 329                 # input routine for this.
 330
 331                 $typemap = array(
 332                         'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
 333                         'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( __CLASS__, 'imageJpegWrapper' ) ),
 334                         'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
 335                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
 336                         'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
 337                 );
 338                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 339                         $err = 'Image type not supported';
 340                         wfDebug( "$err\n" );
 341                         $errMsg = wfMsg ( 'thumbnail_image-type' );
 342                         return $this->getMediaTransformError( $params, $errMsg );
 343                 }
 344                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 345
 346                 if ( !function_exists( $loader ) ) {
 347                         $err = "Incomplete GD library configuration: missing function $loader";
 348                         wfDebug( "$err\n" );
 349                         $errMsg = wfMsg ( 'thumbnail_gd-library', $loader );
 350                         return $this->getMediaTransformError( $params, $errMsg );
 351                 }
 352
 353                 if ( !file_exists( $params['srcPath'] ) ) {
 354                         $err = "File seems to be missing: {$params['srcPath']}";
 355                         wfDebug( "$err\n" );
 356                         $errMsg = wfMsg ( 'thumbnail_image-missing', $params['srcPath'] );
 357                         return $this->getMediaTransformError( $params, $errMsg );
 358                 }
 359
 360                 $src_image = call_user_func( $loader, $params['srcPath'] );
 361                 $dst_image = imagecreatetruecolor( $params['physicalWidth'],
 362                         $params['physicalHeight'] );
 363
 364                 // Initialise the destination image to transparent instead of
 365                 // the default solid black, to support PNG and GIF transparency nicely
 366                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 367                 imagecolortransparent( $dst_image, $background );
 368                 imagealphablending( $dst_image, false );
 369
 370                 if ( $colorStyle == 'palette' ) {
 371                         // Don't resample for paletted GIF images.
 372                         // It may just uglify them, and completely breaks transparency.
 373                         imagecopyresized( $dst_image, $src_image,
 374                                 0, 0, 0, 0,
 375                                 $params['physicalWidth'], $params['physicalHeight'],
 376                                 imagesx( $src_image ), imagesy( $src_image ) );
 377                 } else {
 378                         imagecopyresampled( $dst_image, $src_image,
 379                                 0, 0, 0, 0,
 380                                 $params['physicalWidth'], $params['physicalHeight'],
 381                                 imagesx( $src_image ), imagesy( $src_image ) );
 382                 }
 383
 384                 imagesavealpha( $dst_image, true );
 385
 386                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 387                 imagedestroy( $dst_image );
 388                 imagedestroy( $src_image );
 389
 390                 return false; # No error
 391         }
 392
 393         /**
 394          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 395          * See InterpretImageProperties() in magick/property.c
 396          */
 397         function escapeMagickProperty( $s ) {
 398                 // Double the backslashes
 399                 $s = str_replace( '\\', '\\\\', $s );
 400                 // Double the percents
 401                 $s = str_replace( '%', '%%', $s );
 402                 // Escape initial - or @
 403                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 404                         $s = '\\' . $s;
 405                 }
 406                 return $s;
 407         }
 408
 409         /**
 410          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 411          * and GetPathComponent() in magick/utility.c.
 412          *
 413          * This won't work with an initial ~ or @, so input files should be prefixed
 414          * with the directory name.
 415          *
 416          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 417          * it's broken in a way that doesn't involve trying to convert every file
 418          * in a directory, so we're better off escaping and waiting for the bugfix
 419          * to filter down to users.
 420          *
 421          * @param $path string The file path
 422          * @param $scene string The scene specification, or false if there is none
 423          */
 424         function escapeMagickInput( $path, $scene = false ) {
 425                 # Die on initial metacharacters (caller should prepend path)
 426                 $firstChar = substr( $path, 0, 1 );
 427                 if ( $firstChar === '~' || $firstChar === '@' ) {
 428                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 429                 }
 430
 431                 # Escape glob chars
 432                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 433
 434                 return $this->escapeMagickPath( $path, $scene );
 435         }
 436
 437         /**
 438          * Escape a string for ImageMagick's output filename. See
 439          * InterpretImageFilename() in magick/image.c.
 440          */
 441         function escapeMagickOutput( $path, $scene = false ) {
 442                 $path = str_replace( '%', '%%', $path );
 443                 return $this->escapeMagickPath( $path, $scene );
 444         }
 445
 446         /**
 447          * Armour a string against ImageMagick's GetPathComponent(). This is a
 448          * helper function for escapeMagickInput() and escapeMagickOutput().
 449          *
 450          * @param $path string The file path
 451          * @param $scene string The scene specification, or false if there is none
 452          */
 453         protected function escapeMagickPath( $path, $scene = false ) {
 454                 # Die on format specifiers (other than drive letters). The regex is
 455                 # meant to match all the formats you get from "convert -list format"
 456                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 457                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 458                                 // OK, it's a drive letter
 459                                 // ImageMagick has a similar exception, see IsMagickConflict()
 460                         } else {
 461                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 462                         }
 463                 }
 464
 465                 # If there are square brackets, add a do-nothing scene specification
 466                 # to force a literal interpretation
 467                 if ( $scene === false ) {
 468                         if ( strpos( $path, '[' ) !== false ) {
 469                                 $path .= '[0--1]';
 470                         }
 471                 } else {
 472                         $path .= "[$scene]";
 473                 }
 474                 return $path;
 475         }
 476
 477         /**
 478          * Retrieve the version of the installed ImageMagick
 479          * You can use PHPs version_compare() to use this value
 480          * Value is cached for one hour.
 481          * @return String representing the IM version.
 482          */
 483         protected function getMagickVersion() {
 484                 global $wgMemc;
 485
 486                 $cache = $wgMemc->get( "imagemagick-version" );
 487                 if ( !$cache ) {
 488                         global $wgImageMagickConvertCommand;
 489                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 490                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 491                         $retval = '';
 492                         $return = wfShellExec( $cmd, $retval );
 493                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 494                         if ( $x != 1 ) {
 495                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 496                                 return null;
 497                         }
 498                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 499                         return $matches[1];
 500                 }
 501                 return $cache;
 502         }
 503
 504         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 505                 imageinterlace( $dst_image );
 506                 imagejpeg( $dst_image, $thumbPath, 95 );
 507         }
 508
 509
 510         function getMetadata( $image, $filename ) {
 511                 global $wgShowEXIF;
 512                 if ( $wgShowEXIF && file_exists( $filename ) ) {
 513                         $exif = new Exif( $filename );
 514                         $data = $exif->getFilteredData();
 515                         if ( $data ) {
 516                                 $data['MEDIAWIKI_EXIF_VERSION'] = Exif::version();
 517                                 return serialize( $data );
 518                         } else {
 519                                 return '0';
 520                         }
 521                 } else {
 522                         return '';
 523                 }
 524         }
 525
 526         function getMetadataType( $image ) {
 527                 return 'exif';
 528         }
 529
 530         function isMetadataValid( $image, $metadata ) {
 531                 global $wgShowEXIF;
 532                 if ( !$wgShowEXIF ) {
 533                         # Metadata disabled and so an empty field is expected
 534                         return true;
 535                 }
 536                 if ( $metadata === '0' ) {
 537                         # Special value indicating that there is no EXIF data in the file
 538                         return true;
 539                 }
 540                 wfSuppressWarnings();
 541                 $exif = unserialize( $metadata );
 542                 wfRestoreWarnings();
 543                 if ( !isset( $exif['MEDIAWIKI_EXIF_VERSION'] ) ||
 544                         $exif['MEDIAWIKI_EXIF_VERSION'] != Exif::version() )
 545                 {
 546                         # Wrong version
 547                         wfDebug( __METHOD__ . ": wrong version\n" );
 548                         return false;
 549                 }
 550                 return true;
 551         }
 552
 553         /**
 554          * Get a list of EXIF metadata items which should be displayed when
 555          * the metadata table is collapsed.
 556          *
 557          * @return array of strings
 558          * @access private
 559          */
 560         function visibleMetadataFields() {
 561                 $fields = array();
 562                 $lines = explode( "\n", wfMsgForContent( 'metadata-fields' ) );
 563                 foreach ( $lines as $line ) {
 564                         $matches = array();
 565                         if ( preg_match( '/^\\*\s*(.*?)\s*$/', $line, $matches ) ) {
 566                                 $fields[] = $matches[1];
 567                         }
 568                 }
 569                 $fields = array_map( 'strtolower', $fields );
 570                 return $fields;
 571         }
 572
 573         function formatMetadata( $image ) {
 574                 $result = array(
 575                         'visible' => array(),
 576                         'collapsed' => array()
 577                 );
 578                 $metadata = $image->getMetadata();
 579                 if ( !$metadata ) {
 580                         return false;
 581                 }
 582                 $exif = unserialize( $metadata );
 583                 if ( !$exif ) {
 584                         return false;
 585                 }
 586                 unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
 587                 $format = new FormatExif( $exif );
 588
 589                 $formatted = $format->getFormattedData();
 590                 // Sort fields into visible and collapsed
 591                 $visibleFields = $this->visibleMetadataFields();
 592                 foreach ( $formatted as $name => $value ) {
 593                         $tag = strtolower( $name );
 594                         self::addMeta( $result,
 595                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 596                                 'exif',
 597                                 $tag,
 598                                 $value
 599                         );
 600                 }
 601                 return $result;
 602         }
 603 }