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, but don't add the flag if there's no comment
 242                         ( $params['comment'] !== ''
 243                                 ? " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) )
 244                                 : '' ) .
 245                         " -depth 8 $sharpen" .
 246                         " {$animation_post} " .
 247                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) ) . " 2>&1";
 248
 249                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 250                 wfProfileIn( 'convert' );
 251                 $retval = 0;
 252                 $err = wfShellExec( $cmd, $retval, $env );
 253                 wfProfileOut( 'convert' );
 254
 255                 if ( $retval !== 0 ) {
 256                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 257                         return $this->getMediaTransformError( $params, $err );
 258                 }
 259
 260                 return false; # No error
 261         }
 262
 263         /**
 264          * Transform an image using a custom command
 265          *
 266          * @param $image File File associated with this thumbnail
 267          * @param $params array Array with scaler params
 268          *
 269          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 270          */
 271         protected function transformCustom( $image, $params ) {
 272                 # Use a custom convert command
 273                 global $wgCustomConvertCommand;
 274
 275                 # Variables: %s %d %w %h
 276                 $src = wfEscapeShellArg( $params['srcPath'] );
 277                 $dst = wfEscapeShellArg( $params['dstPath'] );
 278                 $cmd = $wgCustomConvertCommand;
 279                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 280                 $cmd = str_replace( '%h', $params['physicalHeight'],
 281                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 282                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 283                 wfProfileIn( 'convert' );
 284                 $retval = 0;
 285                 $err = wfShellExec( $cmd, $retval );
 286                 wfProfileOut( 'convert' );
 287
 288                 if ( $retval !== 0 ) {
 289                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 290                         return $this->getMediaTransformError( $params, $err );
 291                 }
 292                 return false; # No error
 293         }
 294
 295         /**
 296          * Log an error that occured in an external process
 297          *
 298          * @param $retval int
 299          * @param $err int
 300          * @param $cmd string
 301          */
 302         protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
 303                 wfDebugLog( 'thumbnail',
 304                         sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 305                                         wfHostname(), $retval, trim( $err ), $cmd ) );
 306         }
 307         /**
 308          * Get a MediaTransformError with error 'thumbnail_error'
 309          *
 310          * @param $params array Parameter array as passed to the transform* functions
 311          * @param $errMsg string Error message
 312          * @return MediaTransformError
 313          */
 314         protected function getMediaTransformError( $params, $errMsg ) {
 315                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 316                                         $params['clientHeight'], $errMsg );
 317         }
 318
 319         /**
 320          * Transform an image using the built in GD library
 321          *
 322          * @param $image File File associated with this thumbnail
 323          * @param $params array Array with scaler params
 324          *
 325          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 326          */
 327         protected function transformGd( $image, $params ) {
 328                 # Use PHP's builtin GD library functions.
 329                 #
 330                 # First find out what kind of file this is, and select the correct
 331                 # input routine for this.
 332
 333                 $typemap = array(
 334                         'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
 335                         'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( __CLASS__, 'imageJpegWrapper' ) ),
 336                         'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
 337                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
 338                         'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
 339                 );
 340                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 341                         $err = 'Image type not supported';
 342                         wfDebug( "$err\n" );
 343                         $errMsg = wfMsg ( 'thumbnail_image-type' );
 344                         return $this->getMediaTransformError( $params, $errMsg );
 345                 }
 346                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 347
 348                 if ( !function_exists( $loader ) ) {
 349                         $err = "Incomplete GD library configuration: missing function $loader";
 350                         wfDebug( "$err\n" );
 351                         $errMsg = wfMsg ( 'thumbnail_gd-library', $loader );
 352                         return $this->getMediaTransformError( $params, $errMsg );
 353                 }
 354
 355                 if ( !file_exists( $params['srcPath'] ) ) {
 356                         $err = "File seems to be missing: {$params['srcPath']}";
 357                         wfDebug( "$err\n" );
 358                         $errMsg = wfMsg ( 'thumbnail_image-missing', $params['srcPath'] );
 359                         return $this->getMediaTransformError( $params, $errMsg );
 360                 }
 361
 362                 $src_image = call_user_func( $loader, $params['srcPath'] );
 363                 $dst_image = imagecreatetruecolor( $params['physicalWidth'],
 364                         $params['physicalHeight'] );
 365
 366                 // Initialise the destination image to transparent instead of
 367                 // the default solid black, to support PNG and GIF transparency nicely
 368                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 369                 imagecolortransparent( $dst_image, $background );
 370                 imagealphablending( $dst_image, false );
 371
 372                 if ( $colorStyle == 'palette' ) {
 373                         // Don't resample for paletted GIF images.
 374                         // It may just uglify them, and completely breaks transparency.
 375                         imagecopyresized( $dst_image, $src_image,
 376                                 0, 0, 0, 0,
 377                                 $params['physicalWidth'], $params['physicalHeight'],
 378                                 imagesx( $src_image ), imagesy( $src_image ) );
 379                 } else {
 380                         imagecopyresampled( $dst_image, $src_image,
 381                                 0, 0, 0, 0,
 382                                 $params['physicalWidth'], $params['physicalHeight'],
 383                                 imagesx( $src_image ), imagesy( $src_image ) );
 384                 }
 385
 386                 imagesavealpha( $dst_image, true );
 387
 388                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 389                 imagedestroy( $dst_image );
 390                 imagedestroy( $src_image );
 391
 392                 return false; # No error
 393         }
 394
 395         /**
 396          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 397          * See InterpretImageProperties() in magick/property.c
 398          */
 399         function escapeMagickProperty( $s ) {
 400                 // Double the backslashes
 401                 $s = str_replace( '\\', '\\\\', $s );
 402                 // Double the percents
 403                 $s = str_replace( '%', '%%', $s );
 404                 // Escape initial - or @
 405                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 406                         $s = '\\' . $s;
 407                 }
 408                 return $s;
 409         }
 410
 411         /**
 412          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 413          * and GetPathComponent() in magick/utility.c.
 414          *
 415          * This won't work with an initial ~ or @, so input files should be prefixed
 416          * with the directory name.
 417          *
 418          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 419          * it's broken in a way that doesn't involve trying to convert every file
 420          * in a directory, so we're better off escaping and waiting for the bugfix
 421          * to filter down to users.
 422          *
 423          * @param $path string The file path
 424          * @param $scene string The scene specification, or false if there is none
 425          */
 426         function escapeMagickInput( $path, $scene = false ) {
 427                 # Die on initial metacharacters (caller should prepend path)
 428                 $firstChar = substr( $path, 0, 1 );
 429                 if ( $firstChar === '~' || $firstChar === '@' ) {
 430                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 431                 }
 432
 433                 # Escape glob chars
 434                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 435
 436                 return $this->escapeMagickPath( $path, $scene );
 437         }
 438
 439         /**
 440          * Escape a string for ImageMagick's output filename. See
 441          * InterpretImageFilename() in magick/image.c.
 442          */
 443         function escapeMagickOutput( $path, $scene = false ) {
 444                 $path = str_replace( '%', '%%', $path );
 445                 return $this->escapeMagickPath( $path, $scene );
 446         }
 447
 448         /**
 449          * Armour a string against ImageMagick's GetPathComponent(). This is a
 450          * helper function for escapeMagickInput() and escapeMagickOutput().
 451          *
 452          * @param $path string The file path
 453          * @param $scene string The scene specification, or false if there is none
 454          */
 455         protected function escapeMagickPath( $path, $scene = false ) {
 456                 # Die on format specifiers (other than drive letters). The regex is
 457                 # meant to match all the formats you get from "convert -list format"
 458                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 459                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 460                                 // OK, it's a drive letter
 461                                 // ImageMagick has a similar exception, see IsMagickConflict()
 462                         } else {
 463                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 464                         }
 465                 }
 466
 467                 # If there are square brackets, add a do-nothing scene specification
 468                 # to force a literal interpretation
 469                 if ( $scene === false ) {
 470                         if ( strpos( $path, '[' ) !== false ) {
 471                                 $path .= '[0--1]';
 472                         }
 473                 } else {
 474                         $path .= "[$scene]";
 475                 }
 476                 return $path;
 477         }
 478
 479         /**
 480          * Retrieve the version of the installed ImageMagick
 481          * You can use PHPs version_compare() to use this value
 482          * Value is cached for one hour.
 483          * @return String representing the IM version.
 484          */
 485         protected function getMagickVersion() {
 486                 global $wgMemc;
 487
 488                 $cache = $wgMemc->get( "imagemagick-version" );
 489                 if ( !$cache ) {
 490                         global $wgImageMagickConvertCommand;
 491                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 492                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 493                         $retval = '';
 494                         $return = wfShellExec( $cmd, $retval );
 495                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 496                         if ( $x != 1 ) {
 497                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 498                                 return null;
 499                         }
 500                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 501                         return $matches[1];
 502                 }
 503                 return $cache;
 504         }
 505
 506         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 507                 imageinterlace( $dst_image );
 508                 imagejpeg( $dst_image, $thumbPath, 95 );
 509         }
 510
 511
 512         function getMetadata( $image, $filename ) {
 513                 global $wgShowEXIF;
 514                 if ( $wgShowEXIF && file_exists( $filename ) ) {
 515                         $exif = new Exif( $filename );
 516                         $data = $exif->getFilteredData();
 517                         if ( $data ) {
 518                                 $data['MEDIAWIKI_EXIF_VERSION'] = Exif::version();
 519                                 return serialize( $data );
 520                         } else {
 521                                 return '0';
 522                         }
 523                 } else {
 524                         return '';
 525                 }
 526         }
 527
 528         function getMetadataType( $image ) {
 529                 return 'exif';
 530         }
 531
 532         function isMetadataValid( $image, $metadata ) {
 533                 global $wgShowEXIF;
 534                 if ( !$wgShowEXIF ) {
 535                         # Metadata disabled and so an empty field is expected
 536                         return true;
 537                 }
 538                 if ( $metadata === '0' ) {
 539                         # Special value indicating that there is no EXIF data in the file
 540                         return true;
 541                 }
 542                 wfSuppressWarnings();
 543                 $exif = unserialize( $metadata );
 544                 wfRestoreWarnings();
 545                 if ( !isset( $exif['MEDIAWIKI_EXIF_VERSION'] ) ||
 546                         $exif['MEDIAWIKI_EXIF_VERSION'] != Exif::version() )
 547                 {
 548                         # Wrong version
 549                         wfDebug( __METHOD__ . ": wrong version\n" );
 550                         return false;
 551                 }
 552                 return true;
 553         }
 554
 555         /**
 556          * Get a list of EXIF metadata items which should be displayed when
 557          * the metadata table is collapsed.
 558          *
 559          * @return array of strings
 560          * @access private
 561          */
 562         function visibleMetadataFields() {
 563                 $fields = array();
 564                 $lines = explode( "\n", wfMsgForContent( 'metadata-fields' ) );
 565                 foreach ( $lines as $line ) {
 566                         $matches = array();
 567                         if ( preg_match( '/^\\*\s*(.*?)\s*$/', $line, $matches ) ) {
 568                                 $fields[] = $matches[1];
 569                         }
 570                 }
 571                 $fields = array_map( 'strtolower', $fields );
 572                 return $fields;
 573         }
 574
 575         function formatMetadata( $image ) {
 576                 $result = array(
 577                         'visible' => array(),
 578                         'collapsed' => array()
 579                 );
 580                 $metadata = $image->getMetadata();
 581                 if ( !$metadata ) {
 582                         return false;
 583                 }
 584                 $exif = unserialize( $metadata );
 585                 if ( !$exif ) {
 586                         return false;
 587                 }
 588                 unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
 589                 $format = new FormatExif( $exif );
 590
 591                 $formatted = $format->getFormattedData();
 592                 // Sort fields into visible and collapsed
 593                 $visibleFields = $this->visibleMetadataFields();
 594                 foreach ( $formatted as $name => $value ) {
 595                         $tag = strtolower( $name );
 596                         self::addMeta( $result,
 597                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 598                                 'exif',
 599                                 $tag,
 600                                 $value
 601                         );
 602                 }
 603                 return $result;
 604         }
 605 }