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
  16         /**
  17          * @param $image File
  18          * @param $params array Transform parameters. Entries with the keys 'width'
  19          * and 'height' are the respective screen width and height, while the keys
  20          * 'physicalWidth' and 'physicalHeight' indicate the thumbnail dimensions.
  21          * @return bool
  22          */
  23         function normaliseParams( $image, &$params ) {
  24                 global $wgMaxImageArea;
  25                 if ( !parent::normaliseParams( $image, $params ) ) {
  26                         return false;
  27                 }
  28
  29                 $mimeType = $image->getMimeType();
  30                 # Obtain the source, pre-rotation dimensions
  31                 $srcWidth = $image->getWidth( $params['page'] );
  32                 $srcHeight = $image->getHeight( $params['page'] );
  33
  34                 # Don't make an image bigger than the source
  35                 if ( $params['physicalWidth'] >= $srcWidth ) {
  36                         $params['physicalWidth'] = $srcWidth;
  37                         $params['physicalHeight'] = $srcHeight;
  38
  39                         # Skip scaling limit checks if no scaling is required
  40                         # due to requested size being bigger than source.
  41                         if ( !$image->mustRender() ) {
  42                                 return true;
  43                         }
  44                 }
  45
  46                 # Don't thumbnail an image so big that it will fill hard drives and send servers into swap
  47                 # JPEG has the handy property of allowing thumbnailing without full decompression, so we make
  48                 # an exception for it.
  49                 # @todo FIXME: This actually only applies to ImageMagick
  50                 if ( $mimeType !== 'image/jpeg' &&
  51                         $srcWidth * $srcHeight > $wgMaxImageArea )
  52                 {
  53                         return false;
  54                 }
  55
  56                 return true;
  57         }
  58
  59         /**
  60          * Extracts the width/height if the image will be scaled before rotating
  61          *
  62          * This will match the physical size/aspect ratio of the original image
  63          * prior to application of the rotation -- so for a portrait image that's
  64          * stored as raw landscape with 90-degress rotation, the resulting size
  65          * will be wider than it is tall.
  66          *
  67          * @param $params array Parameters as returned by normaliseParams
  68          * @param $rotation int The rotation angle that will be applied
  69          * @return array ($width, $height) array
  70          */
  71         public function extractPreRotationDimensions( $params, $rotation ) {
  72                 if ( $rotation == 90 || $rotation == 270 ) {
  73                         # We'll resize before rotation, so swap the dimensions again
  74                         $width = $params['physicalHeight'];
  75                         $height = $params['physicalWidth'];
  76                 } else {
  77                         $width = $params['physicalWidth'];
  78                         $height = $params['physicalHeight'];
  79                 }
  80                 return array( $width, $height );
  81         }
  82
  83
  84         // Function that returns the number of pixels to be thumbnailed.
  85         // Intended for animated GIFs to multiply by the number of frames.
  86         function getImageArea( $image, $width, $height ) {
  87                 return $width * $height;
  88         }
  89
  90         /**
  91          * @param $image File
  92          * @param  $dstPath
  93          * @param  $dstUrl
  94          * @param  $params
  95          * @param int $flags
  96          * @return MediaTransformError|ThumbnailImage|TransformParameterError
  97          */
  98         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
  99                 if ( !$this->normaliseParams( $image, $params ) ) {
 100                         return new TransformParameterError( $params );
 101                 }
 102                 # Create a parameter array to pass to the scaler
 103                 $scalerParams = array(
 104                         # The size to which the image will be resized
 105                         'physicalWidth' => $params['physicalWidth'],
 106                         'physicalHeight' => $params['physicalHeight'],
 107                         'physicalDimensions' => "{$params['physicalWidth']}x{$params['physicalHeight']}",
 108                         # The size of the image on the page
 109                         'clientWidth' => $params['width'],
 110                         'clientHeight' => $params['height'],
 111                         # Comment as will be added to the EXIF of the thumbnail
 112                         'comment' => isset( $params['descriptionUrl'] ) ?
 113                                 "File source: {$params['descriptionUrl']}" : '',
 114                         # Properties of the original image
 115                         'srcWidth' => $image->getWidth(),
 116                         'srcHeight' => $image->getHeight(),
 117                         'mimeType' => $image->getMimeType(),
 118                         'srcPath' => $image->getPath(),
 119                         'dstPath' => $dstPath,
 120                         'dstUrl' => $dstUrl,
 121                 );
 122
 123                 wfDebug( __METHOD__ . ": creating {$scalerParams['physicalDimensions']} thumbnail at $dstPath\n" );
 124
 125                 if ( !$image->mustRender() &&
 126                                 $scalerParams['physicalWidth'] == $scalerParams['srcWidth']
 127                                 && $scalerParams['physicalHeight'] == $scalerParams['srcHeight'] ) {
 128
 129                         # normaliseParams (or the user) wants us to return the unscaled image
 130                         wfDebug( __METHOD__ . ": returning unscaled image\n" );
 131                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 132                 }
 133
 134                 # Determine scaler type
 135                 $scaler = self::getScalerType( $dstPath );
 136                 wfDebug( __METHOD__ . ": scaler $scaler\n" );
 137
 138                 if ( $scaler == 'client' ) {
 139                         # Client-side image scaling, use the source URL
 140                         # Using the destination URL in a TRANSFORM_LATER request would be incorrect
 141                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 142                 }
 143
 144                 if ( $flags & self::TRANSFORM_LATER ) {
 145                         wfDebug( __METHOD__ . ": Transforming later per flags.\n" );
 146                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 147                                 $scalerParams['clientHeight'], $dstPath );
 148                 }
 149
 150                 # Try to make a target path for the thumbnail
 151                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 152                         wfDebug( __METHOD__ . ": Unable to create thumbnail destination directory, falling back to client scaling\n" );
 153                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 154                 }
 155
 156                 # Try a hook
 157                 $mto = null;
 158                 wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
 159                 if ( !is_null( $mto ) ) {
 160                         wfDebug( __METHOD__ . ": Hook to BitmapHandlerTransform created an mto\n" );
 161                         $scaler = 'hookaborted';
 162                 }
 163
 164                 switch ( $scaler ) {
 165                         case 'hookaborted':
 166                                 # Handled by the hook above
 167                                 $err = $mto->isError() ? $mto : false;
 168                                 break;
 169                         case 'im':
 170                                 $err = $this->transformImageMagick( $image, $scalerParams );
 171                                 break;
 172                         case 'custom':
 173                                 $err = $this->transformCustom( $image, $scalerParams );
 174                                 break;
 175                         case 'imext':
 176                                 $err = $this->transformImageMagickExt( $image, $scalerParams );
 177                                 break;
 178                         case 'gd':
 179                         default:
 180                                 $err = $this->transformGd( $image, $scalerParams );
 181                                 break;
 182                 }
 183
 184                 # Remove the file if a zero-byte thumbnail was created, or if there was an error
 185                 $removed = $this->removeBadFile( $dstPath, (bool)$err );
 186                 if ( $err ) {
 187                         # transform returned MediaTransforError
 188                         return $err;
 189                 } elseif ( $removed ) {
 190                         # Thumbnail was zero-byte and had to be removed
 191                         return new MediaTransformError( 'thumbnail_error',
 192                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'] );
 193                 } elseif ( $mto ) {
 194                         return $mto;
 195                 } else {
 196                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 197                                 $scalerParams['clientHeight'], $dstPath );
 198                 }
 199         }
 200
 201         /**
 202          * Returns which scaler type should be used. Creates parent directories
 203          * for $dstPath and returns 'client' on error
 204          *
 205          * @return string client,im,custom,gd
 206          */
 207         protected static function getScalerType( $dstPath, $checkDstPath = true ) {
 208                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
 209
 210                 if ( !$dstPath && $checkDstPath ) {
 211                         # No output path available, client side scaling only
 212                         $scaler = 'client';
 213                 } elseif ( !$wgUseImageResize ) {
 214                         $scaler = 'client';
 215                 } elseif ( $wgUseImageMagick ) {
 216                         $scaler = 'im';
 217                 } elseif ( $wgCustomConvertCommand ) {
 218                         $scaler = 'custom';
 219                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
 220                         $scaler = 'gd';
 221                 } elseif ( class_exists( 'Imagick' ) ) {
 222                         $scaler = 'imext';
 223                 } else {
 224                         $scaler = 'client';
 225                 }
 226                 return $scaler;
 227         }
 228
 229         /**
 230          * Get a ThumbnailImage that respresents an image that will be scaled
 231          * client side
 232          *
 233          * @param $image File File associated with this thumbnail
 234          * @param $params array Array with scaler params
 235          * @return ThumbnailImage
 236          *
 237          * @fixme no rotation support
 238          */
 239         protected function getClientScalingThumbnailImage( $image, $params ) {
 240                 return new ThumbnailImage( $image, $image->getURL(),
 241                                 $params['clientWidth'], $params['clientHeight'], $params['srcPath'] );
 242         }
 243
 244         /**
 245          * Transform an image using ImageMagick
 246          *
 247          * @param $image File File associated with this thumbnail
 248          * @param $params array Array with scaler params
 249          *
 250          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 251          */
 252         protected function transformImageMagick( $image, $params ) {
 253                 # use ImageMagick
 254                 global $wgSharpenReductionThreshold, $wgSharpenParameter,
 255                         $wgMaxAnimatedGifArea,
 256                         $wgImageMagickTempDir, $wgImageMagickConvertCommand;
 257
 258                 $quality = '';
 259                 $sharpen = '';
 260                 $scene = false;
 261                 $animation_pre = '';
 262                 $animation_post = '';
 263                 $decoderHint = '';
 264                 if ( $params['mimeType'] == 'image/jpeg' ) {
 265                         $quality = "-quality 80"; // 80%
 266                         # Sharpening, see bug 6193
 267                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 268                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 269                                         < $wgSharpenReductionThreshold ) {
 270                                 $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 271                         }
 272                         // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 273                         $decoderHint = "-define jpeg:size={$params['physicalDimensions']}";
 274
 275                 } elseif ( $params['mimeType'] == 'image/png' ) {
 276                         $quality = "-quality 95"; // zlib 9, adaptive filtering
 277
 278                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 279                         if ( $this->getImageArea( $image, $params['srcWidth'],
 280                                         $params['srcHeight'] ) > $wgMaxAnimatedGifArea ) {
 281                                 // Extract initial frame only; we're so big it'll
 282                                 // be a total drag. :P
 283                                 $scene = 0;
 284
 285                         } elseif ( $this->isAnimatedImage( $image ) ) {
 286                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 287                                 $animation_pre = '-coalesce';
 288                                 // We optimize the output, but -optimize is broken,
 289                                 // use optimizeTransparency instead (bug 11822)
 290                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 291                                         $animation_post = '-fuzz 5% -layers optimizeTransparency';
 292                                 }
 293                         }
 294                 }
 295
 296                 // Use one thread only, to avoid deadlock bugs on OOM
 297                 $env = array( 'OMP_NUM_THREADS' => 1 );
 298                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 299                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 300                 }
 301
 302                 $rotation = $this->getRotation( $image );
 303                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 304
 305                 $cmd  =
 306                         wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 307                         // Specify white background color, will be used for transparent images
 308                         // in Internet Explorer/Windows instead of default black.
 309                         " {$quality} -background white" .
 310                         " {$decoderHint} " .
 311                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 312                         " {$animation_pre}" .
 313                         // For the -thumbnail option a "!" is needed to force exact size,
 314                         // or ImageMagick may decide your ratio is wrong and slice off
 315                         // a pixel.
 316                         " -thumbnail " . wfEscapeShellArg( "{$width}x{$height}!" ) .
 317                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 318                         ( $params['comment'] !== ''
 319                                 ? " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) )
 320                                 : '' ) .
 321                         " -depth 8 $sharpen " .
 322                         " -rotate -$rotation " .
 323                         " {$animation_post} " .
 324                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) ) . " 2>&1";
 325
 326                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 327                 wfProfileIn( 'convert' );
 328                 $retval = 0;
 329                 $err = wfShellExec( $cmd, $retval, $env );
 330                 wfProfileOut( 'convert' );
 331
 332                 if ( $retval !== 0 ) {
 333                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 334                         return $this->getMediaTransformError( $params, $err );
 335                 }
 336
 337                 return false; # No error
 338         }
 339
 340         /**
 341          * Transform an image using the Imagick PHP extension
 342          *
 343          * @param $image File File associated with this thumbnail
 344          * @param $params array Array with scaler params
 345          *
 346          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 347          */
 348         protected function transformImageMagickExt( $image, $params ) {
 349                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea;
 350
 351                 try {
 352                         $im = new Imagick();
 353                         $im->readImage( $params['srcPath'] );
 354
 355                         if ( $params['mimeType'] == 'image/jpeg' ) {
 356                                 // Sharpening, see bug 6193
 357                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 358                                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 359                                                 < $wgSharpenReductionThreshold ) {
 360                                         // Hack, since $wgSharpenParamater is written specifically for the command line convert
 361                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 362                                         $im->sharpenImage( $radius, $sigma );
 363                                 }
 364                                 $im->setCompressionQuality( 80 );
 365                         } elseif( $params['mimeType'] == 'image/png' ) {
 366                                 $im->setCompressionQuality( 95 );
 367                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 368                                 if ( $this->getImageArea( $image, $params['srcWidth'],
 369                                                 $params['srcHeight'] ) > $wgMaxAnimatedGifArea ) {
 370                                         // Extract initial frame only; we're so big it'll
 371                                         // be a total drag. :P
 372                                         $im->setImageScene( 0 );
 373                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 374                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 375                                         $im = $im->coalesceImages();
 376                                 }
 377                         }
 378
 379                         $rotation = $this->getRotation( $image );
 380                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 381
 382                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 383
 384                         // Call Imagick::thumbnailImage on each frame
 385                         foreach ( $im as $i => $frame ) {
 386                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 387                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 388                                 }
 389                         }
 390                         $im->setImageDepth( 8 );
 391
 392                         if ( $rotation ) {
 393                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 394                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 395                                 }
 396                         }
 397
 398                         if ( $this->isAnimatedImage( $image ) ) {
 399                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 400                                 // This is broken somehow... can't find out how to fix it
 401                                 $result = $im->writeImages( $params['dstPath'], true );
 402                         } else {
 403                                 $result = $im->writeImage( $params['dstPath'] );
 404                         }
 405                         if ( !$result ) {
 406                                 return $this->getMediaTransformError( $params,
 407                                         "Unable to write thumbnail to {$params['dstPath']}" );
 408                         }
 409
 410                 } catch ( ImagickException $e ) {
 411                         return $this->getMediaTransformError( $params, $e->getMessage() );
 412                 }
 413
 414                 return false;
 415
 416         }
 417
 418         /**
 419          * Transform an image using a custom command
 420          *
 421          * @param $image File File associated with this thumbnail
 422          * @param $params array Array with scaler params
 423          *
 424          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 425          */
 426         protected function transformCustom( $image, $params ) {
 427                 # Use a custom convert command
 428                 global $wgCustomConvertCommand;
 429
 430                 # Variables: %s %d %w %h
 431                 $src = wfEscapeShellArg( $params['srcPath'] );
 432                 $dst = wfEscapeShellArg( $params['dstPath'] );
 433                 $cmd = $wgCustomConvertCommand;
 434                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 435                 $cmd = str_replace( '%h', $params['physicalHeight'],
 436                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 437                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 438                 wfProfileIn( 'convert' );
 439                 $retval = 0;
 440                 $err = wfShellExec( $cmd, $retval );
 441                 wfProfileOut( 'convert' );
 442
 443                 if ( $retval !== 0 ) {
 444                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 445                         return $this->getMediaTransformError( $params, $err );
 446                 }
 447                 return false; # No error
 448         }
 449
 450         /**
 451          * Log an error that occured in an external process
 452          *
 453          * @param $retval int
 454          * @param $err int
 455          * @param $cmd string
 456          */
 457         protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
 458                 wfDebugLog( 'thumbnail',
 459                         sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 460                                         wfHostname(), $retval, trim( $err ), $cmd ) );
 461         }
 462         /**
 463          * Get a MediaTransformError with error 'thumbnail_error'
 464          *
 465          * @param $params array Parameter array as passed to the transform* functions
 466          * @param $errMsg string Error message
 467          * @return MediaTransformError
 468          */
 469         public function getMediaTransformError( $params, $errMsg ) {
 470                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 471                                         $params['clientHeight'], $errMsg );
 472         }
 473
 474         /**
 475          * Transform an image using the built in GD library
 476          *
 477          * @param $image File File associated with this thumbnail
 478          * @param $params array Array with scaler params
 479          *
 480          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 481          */
 482         protected function transformGd( $image, $params ) {
 483                 # Use PHP's builtin GD library functions.
 484                 #
 485                 # First find out what kind of file this is, and select the correct
 486                 # input routine for this.
 487
 488                 $typemap = array(
 489                         'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
 490                         'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( __CLASS__, 'imageJpegWrapper' ) ),
 491                         'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
 492                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
 493                         'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
 494                 );
 495                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 496                         $err = 'Image type not supported';
 497                         wfDebug( "$err\n" );
 498                         $errMsg = wfMsg ( 'thumbnail_image-type' );
 499                         return $this->getMediaTransformError( $params, $errMsg );
 500                 }
 501                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 502
 503                 if ( !function_exists( $loader ) ) {
 504                         $err = "Incomplete GD library configuration: missing function $loader";
 505                         wfDebug( "$err\n" );
 506                         $errMsg = wfMsg ( 'thumbnail_gd-library', $loader );
 507                         return $this->getMediaTransformError( $params, $errMsg );
 508                 }
 509
 510                 if ( !file_exists( $params['srcPath'] ) ) {
 511                         $err = "File seems to be missing: {$params['srcPath']}";
 512                         wfDebug( "$err\n" );
 513                         $errMsg = wfMsg ( 'thumbnail_image-missing', $params['srcPath'] );
 514                         return $this->getMediaTransformError( $params, $errMsg );
 515                 }
 516
 517                 $src_image = call_user_func( $loader, $params['srcPath'] );
 518
 519                 $rotation = function_exists( 'imagerotate' ) ? $this->getRotation( $image ) : 0;
 520                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 521                 $dst_image = imagecreatetruecolor( $width, $height );
 522
 523                 // Initialise the destination image to transparent instead of
 524                 // the default solid black, to support PNG and GIF transparency nicely
 525                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 526                 imagecolortransparent( $dst_image, $background );
 527                 imagealphablending( $dst_image, false );
 528
 529                 if ( $colorStyle == 'palette' ) {
 530                         // Don't resample for paletted GIF images.
 531                         // It may just uglify them, and completely breaks transparency.
 532                         imagecopyresized( $dst_image, $src_image,
 533                                 0, 0, 0, 0,
 534                                 $width, $height,
 535                                 imagesx( $src_image ), imagesy( $src_image ) );
 536                 } else {
 537                         imagecopyresampled( $dst_image, $src_image,
 538                                 0, 0, 0, 0,
 539                                 $width, $height,
 540                                 imagesx( $src_image ), imagesy( $src_image ) );
 541                 }
 542
 543                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 544                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 545                         imagedestroy( $dst_image );
 546                         $dst_image = $rot_image;
 547                 }
 548
 549                 imagesavealpha( $dst_image, true );
 550
 551                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 552                 imagedestroy( $dst_image );
 553                 imagedestroy( $src_image );
 554
 555                 return false; # No error
 556         }
 557
 558         /**
 559          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 560          * See InterpretImageProperties() in magick/property.c
 561          */
 562         function escapeMagickProperty( $s ) {
 563                 // Double the backslashes
 564                 $s = str_replace( '\\', '\\\\', $s );
 565                 // Double the percents
 566                 $s = str_replace( '%', '%%', $s );
 567                 // Escape initial - or @
 568                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 569                         $s = '\\' . $s;
 570                 }
 571                 return $s;
 572         }
 573
 574         /**
 575          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 576          * and GetPathComponent() in magick/utility.c.
 577          *
 578          * This won't work with an initial ~ or @, so input files should be prefixed
 579          * with the directory name.
 580          *
 581          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 582          * it's broken in a way that doesn't involve trying to convert every file
 583          * in a directory, so we're better off escaping and waiting for the bugfix
 584          * to filter down to users.
 585          *
 586          * @param $path string The file path
 587          * @param $scene string The scene specification, or false if there is none
 588          */
 589         function escapeMagickInput( $path, $scene = false ) {
 590                 # Die on initial metacharacters (caller should prepend path)
 591                 $firstChar = substr( $path, 0, 1 );
 592                 if ( $firstChar === '~' || $firstChar === '@' ) {
 593                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 594                 }
 595
 596                 # Escape glob chars
 597                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 598
 599                 return $this->escapeMagickPath( $path, $scene );
 600         }
 601
 602         /**
 603          * Escape a string for ImageMagick's output filename. See
 604          * InterpretImageFilename() in magick/image.c.
 605          */
 606         function escapeMagickOutput( $path, $scene = false ) {
 607                 $path = str_replace( '%', '%%', $path );
 608                 return $this->escapeMagickPath( $path, $scene );
 609         }
 610
 611         /**
 612          * Armour a string against ImageMagick's GetPathComponent(). This is a
 613          * helper function for escapeMagickInput() and escapeMagickOutput().
 614          *
 615          * @param $path string The file path
 616          * @param $scene string The scene specification, or false if there is none
 617          */
 618         protected function escapeMagickPath( $path, $scene = false ) {
 619                 # Die on format specifiers (other than drive letters). The regex is
 620                 # meant to match all the formats you get from "convert -list format"
 621                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 622                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 623                                 // OK, it's a drive letter
 624                                 // ImageMagick has a similar exception, see IsMagickConflict()
 625                         } else {
 626                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 627                         }
 628                 }
 629
 630                 # If there are square brackets, add a do-nothing scene specification
 631                 # to force a literal interpretation
 632                 if ( $scene === false ) {
 633                         if ( strpos( $path, '[' ) !== false ) {
 634                                 $path .= '[0--1]';
 635                         }
 636                 } else {
 637                         $path .= "[$scene]";
 638                 }
 639                 return $path;
 640         }
 641
 642         /**
 643          * Retrieve the version of the installed ImageMagick
 644          * You can use PHPs version_compare() to use this value
 645          * Value is cached for one hour.
 646          * @return String representing the IM version.
 647          */
 648         protected function getMagickVersion() {
 649                 global $wgMemc;
 650
 651                 $cache = $wgMemc->get( "imagemagick-version" );
 652                 if ( !$cache ) {
 653                         global $wgImageMagickConvertCommand;
 654                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 655                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 656                         $retval = '';
 657                         $return = wfShellExec( $cmd, $retval );
 658                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 659                         if ( $x != 1 ) {
 660                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 661                                 return null;
 662                         }
 663                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 664                         return $matches[1];
 665                 }
 666                 return $cache;
 667         }
 668
 669         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 670                 imageinterlace( $dst_image );
 671                 imagejpeg( $dst_image, $thumbPath, 95 );
 672         }
 673
 674         /**
 675          * On supporting image formats, try to read out the low-level orientation
 676          * of the file and return the angle that the file needs to be rotated to
 677          * be viewed.
 678          *
 679          * This information is only useful when manipulating the original file;
 680          * the width and height we normally work with is logical, and will match
 681          * any produced output views.
 682          *
 683          * The base BitmapHandler doesn't understand any metadata formats, so this
 684          * is left up to child classes to implement.
 685          *
 686          * @param $file File
 687          * @return int 0, 90, 180 or 270
 688          */
 689         public function getRotation( $file ) {
 690                 return 0;
 691         }
 692
 693         /**
 694          * Returns whether the current scaler supports rotation (im and gd do)
 695          *
 696          * @return bool
 697          */
 698         public static function canRotate() {
 699                 $scaler = self::getScalerType( null, false );
 700                 switch ( $scaler ) {
 701                         case 'im':
 702                                 # ImageMagick supports autorotation
 703                                 return true;
 704                         case 'imext':
 705                                 # Imagick::rotateImage
 706                                 return true;
 707                         case 'gd':
 708                                 # GD's imagerotate function is used to rotate images, but not
 709                                 # all precompiled PHP versions have that function
 710                                 return function_exists( 'imagerotate' );
 711                         default:
 712                                 # Other scalers don't support rotation
 713                                 return false;
 714                 }
 715         }
 716
 717         /**
 718          * Rerurns whether the file needs to be rendered. Returns true if the
 719          * file requires rotation and we are able to rotate it.
 720          *
 721          * @param $file File
 722          * @return bool
 723          */
 724         public function mustRender( $file ) {
 725                 return self::canRotate() && $this->getRotation( $file ) != 0;
 726         }
 727 }