includes/media/Bitmap.php

   1 <?php
   2 /**
   3  * Generic handler for bitmap images.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Media
  22  */
  23
  24 /**
  25  * Generic handler for bitmap images
  26  *
  27  * @ingroup Media
  28  */
  29 class BitmapHandler extends ImageHandler {
  30         /**
  31          * @param $image File
  32          * @param $params array Transform parameters. Entries with the keys 'width'
  33          * and 'height' are the respective screen width and height, while the keys
  34          * 'physicalWidth' and 'physicalHeight' indicate the thumbnail dimensions.
  35          * @return bool
  36          */
  37         function normaliseParams( $image, &$params ) {
  38                 if ( !parent::normaliseParams( $image, $params ) ) {
  39                         return false;
  40                 }
  41
  42                 # Obtain the source, pre-rotation dimensions
  43                 $srcWidth = $image->getWidth( $params['page'] );
  44                 $srcHeight = $image->getHeight( $params['page'] );
  45
  46                 # Don't make an image bigger than the source
  47                 if ( $params['physicalWidth'] >= $srcWidth ) {
  48                         $params['physicalWidth'] = $srcWidth;
  49                         $params['physicalHeight'] = $srcHeight;
  50
  51                         # Skip scaling limit checks if no scaling is required
  52                         # due to requested size being bigger than source.
  53                         if ( !$image->mustRender() ) {
  54                                 return true;
  55                         }
  56                 }
  57
  58                 # Check if the file is smaller than the maximum image area for thumbnailing
  59                 $checkImageAreaHookResult = null;
  60                 wfRunHooks( 'BitmapHandlerCheckImageArea', array( $image, &$params, &$checkImageAreaHookResult ) );
  61                 if ( is_null( $checkImageAreaHookResult ) ) {
  62                         global $wgMaxImageArea;
  63
  64                         if ( $srcWidth * $srcHeight > $wgMaxImageArea &&
  65                                         !( $image->getMimeType() == 'image/jpeg' &&
  66                                                 self::getScalerType( false, false ) == 'im' ) ) {
  67                                 # Only ImageMagick can efficiently downsize jpg images without loading
  68                                 # the entire file in memory
  69                                 return false;
  70                         }
  71                 } else {
  72                         return $checkImageAreaHookResult;
  73                 }
  74
  75                 return true;
  76         }
  77
  78
  79         /**
  80          * Extracts the width/height if the image will be scaled before rotating
  81          *
  82          * This will match the physical size/aspect ratio of the original image
  83          * prior to application of the rotation -- so for a portrait image that's
  84          * stored as raw landscape with 90-degress rotation, the resulting size
  85          * will be wider than it is tall.
  86          *
  87          * @param $params array Parameters as returned by normaliseParams
  88          * @param $rotation int The rotation angle that will be applied
  89          * @return array ($width, $height) array
  90          */
  91         public function extractPreRotationDimensions( $params, $rotation ) {
  92                 if ( $rotation == 90 || $rotation == 270 ) {
  93                         # We'll resize before rotation, so swap the dimensions again
  94                         $width = $params['physicalHeight'];
  95                         $height = $params['physicalWidth'];
  96                 } else {
  97                         $width = $params['physicalWidth'];
  98                         $height = $params['physicalHeight'];
  99                 }
 100                 return array( $width, $height );
 101         }
 102
 103
 104         /**
 105          * Function that returns the number of pixels to be thumbnailed.
 106          * Intended for animated GIFs to multiply by the number of frames.
 107          *
 108          * @param File $image
 109          * @return int
 110          */
 111         function getImageArea( $image ) {
 112                 return $image->getWidth() * $image->getHeight();
 113         }
 114
 115         /**
 116          * @param $image File
 117          * @param  $dstPath
 118          * @param  $dstUrl
 119          * @param  $params
 120          * @param int $flags
 121          * @return MediaTransformError|ThumbnailImage|TransformParameterError
 122          */
 123         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 124                 if ( !$this->normaliseParams( $image, $params ) ) {
 125                         return new TransformParameterError( $params );
 126                 }
 127                 # Create a parameter array to pass to the scaler
 128                 $scalerParams = array(
 129                         # The size to which the image will be resized
 130                         'physicalWidth' => $params['physicalWidth'],
 131                         'physicalHeight' => $params['physicalHeight'],
 132                         'physicalDimensions' => "{$params['physicalWidth']}x{$params['physicalHeight']}",
 133                         # The size of the image on the page
 134                         'clientWidth' => $params['width'],
 135                         'clientHeight' => $params['height'],
 136                         # Comment as will be added to the EXIF of the thumbnail
 137                         'comment' => isset( $params['descriptionUrl'] ) ?
 138                                 "File source: {$params['descriptionUrl']}" : '',
 139                         # Properties of the original image
 140                         'srcWidth' => $image->getWidth(),
 141                         'srcHeight' => $image->getHeight(),
 142                         'mimeType' => $image->getMimeType(),
 143                         'dstPath' => $dstPath,
 144                         'dstUrl' => $dstUrl,
 145                 );
 146
 147                 # Determine scaler type
 148                 $scaler = self::getScalerType( $dstPath );
 149
 150                 wfDebug( __METHOD__ . ": creating {$scalerParams['physicalDimensions']} thumbnail at $dstPath using scaler $scaler\n" );
 151
 152                 if ( !$image->mustRender() &&
 153                                 $scalerParams['physicalWidth'] == $scalerParams['srcWidth']
 154                                 && $scalerParams['physicalHeight'] == $scalerParams['srcHeight'] ) {
 155
 156                         # normaliseParams (or the user) wants us to return the unscaled image
 157                         wfDebug( __METHOD__ . ": returning unscaled image\n" );
 158                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 159                 }
 160
 161
 162                 if ( $scaler == 'client' ) {
 163                         # Client-side image scaling, use the source URL
 164                         # Using the destination URL in a TRANSFORM_LATER request would be incorrect
 165                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 166                 }
 167
 168                 if ( $flags & self::TRANSFORM_LATER ) {
 169                         wfDebug( __METHOD__ . ": Transforming later per flags.\n" );
 170                         $params = array(
 171                                 'width' => $scalerParams['clientWidth'],
 172                                 'height' => $scalerParams['clientHeight']
 173                         );
 174                         return new ThumbnailImage( $image, $dstUrl, false, $params );
 175                 }
 176
 177                 # Try to make a target path for the thumbnail
 178                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 179                         wfDebug( __METHOD__ . ": Unable to create thumbnail destination directory, falling back to client scaling\n" );
 180                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 181                 }
 182
 183                 # Transform functions and binaries need a FS source file
 184                 $scalerParams['srcPath'] = $image->getLocalRefPath();
 185
 186                 # Try a hook
 187                 $mto = null;
 188                 wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
 189                 if ( !is_null( $mto ) ) {
 190                         wfDebug( __METHOD__ . ": Hook to BitmapHandlerTransform created an mto\n" );
 191                         $scaler = 'hookaborted';
 192                 }
 193
 194                 switch ( $scaler ) {
 195                         case 'hookaborted':
 196                                 # Handled by the hook above
 197                                 $err = $mto->isError() ? $mto : false;
 198                                 break;
 199                         case 'im':
 200                                 $err = $this->transformImageMagick( $image, $scalerParams );
 201                                 break;
 202                         case 'custom':
 203                                 $err = $this->transformCustom( $image, $scalerParams );
 204                                 break;
 205                         case 'imext':
 206                                 $err = $this->transformImageMagickExt( $image, $scalerParams );
 207                                 break;
 208                         case 'gd':
 209                         default:
 210                                 $err = $this->transformGd( $image, $scalerParams );
 211                                 break;
 212                 }
 213
 214                 # Remove the file if a zero-byte thumbnail was created, or if there was an error
 215                 $removed = $this->removeBadFile( $dstPath, (bool)$err );
 216                 if ( $err ) {
 217                         # transform returned MediaTransforError
 218                         return $err;
 219                 } elseif ( $removed ) {
 220                         # Thumbnail was zero-byte and had to be removed
 221                         return new MediaTransformError( 'thumbnail_error',
 222                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'] );
 223                 } elseif ( $mto ) {
 224                         return $mto;
 225                 } else {
 226                         $params = array(
 227                                 'width' => $scalerParams['clientWidth'],
 228                                 'height' => $scalerParams['clientHeight']
 229                         );
 230                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 231                 }
 232         }
 233
 234         /**
 235          * Returns which scaler type should be used. Creates parent directories
 236          * for $dstPath and returns 'client' on error
 237          *
 238          * @return string client,im,custom,gd
 239          */
 240         protected static function getScalerType( $dstPath, $checkDstPath = true ) {
 241                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
 242
 243                 if ( !$dstPath && $checkDstPath ) {
 244                         # No output path available, client side scaling only
 245                         $scaler = 'client';
 246                 } elseif ( !$wgUseImageResize ) {
 247                         $scaler = 'client';
 248                 } elseif ( $wgUseImageMagick ) {
 249                         $scaler = 'im';
 250                 } elseif ( $wgCustomConvertCommand ) {
 251                         $scaler = 'custom';
 252                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
 253                         $scaler = 'gd';
 254                 } elseif ( class_exists( 'Imagick' ) ) {
 255                         $scaler = 'imext';
 256                 } else {
 257                         $scaler = 'client';
 258                 }
 259                 return $scaler;
 260         }
 261
 262         /**
 263          * Get a ThumbnailImage that respresents an image that will be scaled
 264          * client side
 265          *
 266          * @param $image File File associated with this thumbnail
 267          * @param $scalerParams array Array with scaler params
 268          * @return ThumbnailImage
 269          *
 270          * @todo fixme: no rotation support
 271          */
 272         protected function getClientScalingThumbnailImage( $image, $scalerParams ) {
 273                 $params = array(
 274                         'width' => $scalerParams['clientWidth'],
 275                         'height' => $scalerParams['clientHeight']
 276                 );
 277                 return new ThumbnailImage( $image, $image->getURL(), null, $params );
 278         }
 279
 280         /**
 281          * Transform an image using ImageMagick
 282          *
 283          * @param $image File File associated with this thumbnail
 284          * @param $params array Array with scaler params
 285          *
 286          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 287          */
 288         protected function transformImageMagick( $image, $params ) {
 289                 # use ImageMagick
 290                 global $wgSharpenReductionThreshold, $wgSharpenParameter,
 291                         $wgMaxAnimatedGifArea,
 292                         $wgImageMagickTempDir, $wgImageMagickConvertCommand;
 293
 294                 $quality = '';
 295                 $sharpen = '';
 296                 $scene = false;
 297                 $animation_pre = '';
 298                 $animation_post = '';
 299                 $decoderHint = '';
 300                 if ( $params['mimeType'] == 'image/jpeg' ) {
 301                         $quality = "-quality 80"; // 80%
 302                         # Sharpening, see bug 6193
 303                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 304                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 305                                         < $wgSharpenReductionThreshold ) {
 306                                 $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 307                         }
 308                         if ( version_compare( $this->getMagickVersion(), "6.5.6" ) >= 0 ) {
 309                                 // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 310                                 $decoderHint = "-define jpeg:size={$params['physicalDimensions']}";
 311                         }
 312
 313                 } elseif ( $params['mimeType'] == 'image/png' ) {
 314                         $quality = "-quality 95"; // zlib 9, adaptive filtering
 315
 316                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 317                         if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 318                                 // Extract initial frame only; we're so big it'll
 319                                 // be a total drag. :P
 320                                 $scene = 0;
 321
 322                         } elseif ( $this->isAnimatedImage( $image ) ) {
 323                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 324                                 $animation_pre = '-coalesce';
 325                                 // We optimize the output, but -optimize is broken,
 326                                 // use optimizeTransparency instead (bug 11822)
 327                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 328                                         $animation_post = '-fuzz 5% -layers optimizeTransparency';
 329                                 }
 330                         }
 331                 } elseif ( $params['mimeType'] == 'image/x-xcf' ) {
 332                         $animation_post = '-layers merge';
 333                 }
 334
 335                 // Use one thread only, to avoid deadlock bugs on OOM
 336                 $env = array( 'OMP_NUM_THREADS' => 1 );
 337                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 338                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 339                 }
 340
 341                 $rotation = $this->getRotation( $image );
 342                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 343
 344                 $cmd  =
 345                         wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 346                         // Specify white background color, will be used for transparent images
 347                         // in Internet Explorer/Windows instead of default black.
 348                         " {$quality} -background white" .
 349                         " {$decoderHint} " .
 350                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 351                         " {$animation_pre}" .
 352                         // For the -thumbnail option a "!" is needed to force exact size,
 353                         // or ImageMagick may decide your ratio is wrong and slice off
 354                         // a pixel.
 355                         " -thumbnail " . wfEscapeShellArg( "{$width}x{$height}!" ) .
 356                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 357                         ( $params['comment'] !== ''
 358                                 ? " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) )
 359                                 : '' ) .
 360                         " -depth 8 $sharpen " .
 361                         " -rotate -$rotation " .
 362                         " {$animation_post} " .
 363                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) ) . " 2>&1";
 364
 365                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 366                 wfProfileIn( 'convert' );
 367                 $retval = 0;
 368                 $err = wfShellExec( $cmd, $retval, $env );
 369                 wfProfileOut( 'convert' );
 370
 371                 if ( $retval !== 0 ) {
 372                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 373                         return $this->getMediaTransformError( $params, $err );
 374                 }
 375
 376                 return false; # No error
 377         }
 378
 379         /**
 380          * Transform an image using the Imagick PHP extension
 381          *
 382          * @param $image File File associated with this thumbnail
 383          * @param $params array Array with scaler params
 384          *
 385          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 386          */
 387         protected function transformImageMagickExt( $image, $params ) {
 388                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea;
 389
 390                 try {
 391                         $im = new Imagick();
 392                         $im->readImage( $params['srcPath'] );
 393
 394                         if ( $params['mimeType'] == 'image/jpeg' ) {
 395                                 // Sharpening, see bug 6193
 396                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 397                                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 398                                                 < $wgSharpenReductionThreshold ) {
 399                                         // Hack, since $wgSharpenParamater is written specifically for the command line convert
 400                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 401                                         $im->sharpenImage( $radius, $sigma );
 402                                 }
 403                                 $im->setCompressionQuality( 80 );
 404                         } elseif( $params['mimeType'] == 'image/png' ) {
 405                                 $im->setCompressionQuality( 95 );
 406                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 407                                 if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 408                                         // Extract initial frame only; we're so big it'll
 409                                         // be a total drag. :P
 410                                         $im->setImageScene( 0 );
 411                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 412                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 413                                         $im = $im->coalesceImages();
 414                                 }
 415                         }
 416
 417                         $rotation = $this->getRotation( $image );
 418                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 419
 420                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 421
 422                         // Call Imagick::thumbnailImage on each frame
 423                         foreach ( $im as $i => $frame ) {
 424                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 425                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 426                                 }
 427                         }
 428                         $im->setImageDepth( 8 );
 429
 430                         if ( $rotation ) {
 431                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 432                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 433                                 }
 434                         }
 435
 436                         if ( $this->isAnimatedImage( $image ) ) {
 437                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 438                                 // This is broken somehow... can't find out how to fix it
 439                                 $result = $im->writeImages( $params['dstPath'], true );
 440                         } else {
 441                                 $result = $im->writeImage( $params['dstPath'] );
 442                         }
 443                         if ( !$result ) {
 444                                 return $this->getMediaTransformError( $params,
 445                                         "Unable to write thumbnail to {$params['dstPath']}" );
 446                         }
 447
 448                 } catch ( ImagickException $e ) {
 449                         return $this->getMediaTransformError( $params, $e->getMessage() );
 450                 }
 451
 452                 return false;
 453
 454         }
 455
 456         /**
 457          * Transform an image using a custom command
 458          *
 459          * @param $image File File associated with this thumbnail
 460          * @param $params array Array with scaler params
 461          *
 462          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 463          */
 464         protected function transformCustom( $image, $params ) {
 465                 # Use a custom convert command
 466                 global $wgCustomConvertCommand;
 467
 468                 # Variables: %s %d %w %h
 469                 $src = wfEscapeShellArg( $params['srcPath'] );
 470                 $dst = wfEscapeShellArg( $params['dstPath'] );
 471                 $cmd = $wgCustomConvertCommand;
 472                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 473                 $cmd = str_replace( '%h', $params['physicalHeight'],
 474                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 475                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 476                 wfProfileIn( 'convert' );
 477                 $retval = 0;
 478                 $err = wfShellExec( $cmd, $retval );
 479                 wfProfileOut( 'convert' );
 480
 481                 if ( $retval !== 0 ) {
 482                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 483                         return $this->getMediaTransformError( $params, $err );
 484                 }
 485                 return false; # No error
 486         }
 487
 488         /**
 489          * Log an error that occurred in an external process
 490          *
 491          * @param $retval int
 492          * @param $err int
 493          * @param $cmd string
 494          */
 495         protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
 496                 wfDebugLog( 'thumbnail',
 497                         sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 498                                         wfHostname(), $retval, trim( $err ), $cmd ) );
 499         }
 500         /**
 501          * Get a MediaTransformError with error 'thumbnail_error'
 502          *
 503          * @param $params array Parameter array as passed to the transform* functions
 504          * @param $errMsg string Error message
 505          * @return MediaTransformError
 506          */
 507         public function getMediaTransformError( $params, $errMsg ) {
 508                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 509                                         $params['clientHeight'], $errMsg );
 510         }
 511
 512         /**
 513          * Transform an image using the built in GD library
 514          *
 515          * @param $image File File associated with this thumbnail
 516          * @param $params array Array with scaler params
 517          *
 518          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 519          */
 520         protected function transformGd( $image, $params ) {
 521                 # Use PHP's builtin GD library functions.
 522                 #
 523                 # First find out what kind of file this is, and select the correct
 524                 # input routine for this.
 525
 526                 $typemap = array(
 527                         'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
 528                         'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( __CLASS__, 'imageJpegWrapper' ) ),
 529                         'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
 530                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
 531                         'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
 532                 );
 533                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 534                         $err = 'Image type not supported';
 535                         wfDebug( "$err\n" );
 536                         $errMsg = wfMessage( 'thumbnail_image-type' )->text();
 537                         return $this->getMediaTransformError( $params, $errMsg );
 538                 }
 539                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 540
 541                 if ( !function_exists( $loader ) ) {
 542                         $err = "Incomplete GD library configuration: missing function $loader";
 543                         wfDebug( "$err\n" );
 544                         $errMsg = wfMessage( 'thumbnail_gd-library', $loader )->text();
 545                         return $this->getMediaTransformError( $params, $errMsg );
 546                 }
 547
 548                 if ( !file_exists( $params['srcPath'] ) ) {
 549                         $err = "File seems to be missing: {$params['srcPath']}";
 550                         wfDebug( "$err\n" );
 551                         $errMsg = wfMessage( 'thumbnail_image-missing', $params['srcPath'] )->text();
 552                         return $this->getMediaTransformError( $params, $errMsg );
 553                 }
 554
 555                 $src_image = call_user_func( $loader, $params['srcPath'] );
 556
 557                 $rotation = function_exists( 'imagerotate' ) ? $this->getRotation( $image ) : 0;
 558                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 559                 $dst_image = imagecreatetruecolor( $width, $height );
 560
 561                 // Initialise the destination image to transparent instead of
 562                 // the default solid black, to support PNG and GIF transparency nicely
 563                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 564                 imagecolortransparent( $dst_image, $background );
 565                 imagealphablending( $dst_image, false );
 566
 567                 if ( $colorStyle == 'palette' ) {
 568                         // Don't resample for paletted GIF images.
 569                         // It may just uglify them, and completely breaks transparency.
 570                         imagecopyresized( $dst_image, $src_image,
 571                                 0, 0, 0, 0,
 572                                 $width, $height,
 573                                 imagesx( $src_image ), imagesy( $src_image ) );
 574                 } else {
 575                         imagecopyresampled( $dst_image, $src_image,
 576                                 0, 0, 0, 0,
 577                                 $width, $height,
 578                                 imagesx( $src_image ), imagesy( $src_image ) );
 579                 }
 580
 581                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 582                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 583                         imagedestroy( $dst_image );
 584                         $dst_image = $rot_image;
 585                 }
 586
 587                 imagesavealpha( $dst_image, true );
 588
 589                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 590                 imagedestroy( $dst_image );
 591                 imagedestroy( $src_image );
 592
 593                 return false; # No error
 594         }
 595
 596         /**
 597          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 598          * See InterpretImageProperties() in magick/property.c
 599          * @return mixed|string
 600          */
 601         function escapeMagickProperty( $s ) {
 602                 // Double the backslashes
 603                 $s = str_replace( '\\', '\\\\', $s );
 604                 // Double the percents
 605                 $s = str_replace( '%', '%%', $s );
 606                 // Escape initial - or @
 607                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 608                         $s = '\\' . $s;
 609                 }
 610                 return $s;
 611         }
 612
 613         /**
 614          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 615          * and GetPathComponent() in magick/utility.c.
 616          *
 617          * This won't work with an initial ~ or @, so input files should be prefixed
 618          * with the directory name.
 619          *
 620          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 621          * it's broken in a way that doesn't involve trying to convert every file
 622          * in a directory, so we're better off escaping and waiting for the bugfix
 623          * to filter down to users.
 624          *
 625          * @param $path string The file path
 626          * @param bool|string $scene The scene specification, or false if there is none
 627          * @throws MWException
 628          * @return string
 629          */
 630         function escapeMagickInput( $path, $scene = false ) {
 631                 # Die on initial metacharacters (caller should prepend path)
 632                 $firstChar = substr( $path, 0, 1 );
 633                 if ( $firstChar === '~' || $firstChar === '@' ) {
 634                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 635                 }
 636
 637                 # Escape glob chars
 638                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 639
 640                 return $this->escapeMagickPath( $path, $scene );
 641         }
 642
 643         /**
 644          * Escape a string for ImageMagick's output filename. See
 645          * InterpretImageFilename() in magick/image.c.
 646          * @return string
 647          */
 648         function escapeMagickOutput( $path, $scene = false ) {
 649                 $path = str_replace( '%', '%%', $path );
 650                 return $this->escapeMagickPath( $path, $scene );
 651         }
 652
 653         /**
 654          * Armour a string against ImageMagick's GetPathComponent(). This is a
 655          * helper function for escapeMagickInput() and escapeMagickOutput().
 656          *
 657          * @param $path string The file path
 658          * @param bool|string $scene The scene specification, or false if there is none
 659          * @throws MWException
 660          * @return string
 661          */
 662         protected function escapeMagickPath( $path, $scene = false ) {
 663                 # Die on format specifiers (other than drive letters). The regex is
 664                 # meant to match all the formats you get from "convert -list format"
 665                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 666                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 667                                 // OK, it's a drive letter
 668                                 // ImageMagick has a similar exception, see IsMagickConflict()
 669                         } else {
 670                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 671                         }
 672                 }
 673
 674                 # If there are square brackets, add a do-nothing scene specification
 675                 # to force a literal interpretation
 676                 if ( $scene === false ) {
 677                         if ( strpos( $path, '[' ) !== false ) {
 678                                 $path .= '[0--1]';
 679                         }
 680                 } else {
 681                         $path .= "[$scene]";
 682                 }
 683                 return $path;
 684         }
 685
 686         /**
 687          * Retrieve the version of the installed ImageMagick
 688          * You can use PHPs version_compare() to use this value
 689          * Value is cached for one hour.
 690          * @return String representing the IM version.
 691          */
 692         protected function getMagickVersion() {
 693                 global $wgMemc;
 694
 695                 $cache = $wgMemc->get( "imagemagick-version" );
 696                 if ( !$cache ) {
 697                         global $wgImageMagickConvertCommand;
 698                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 699                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 700                         $retval = '';
 701                         $return = wfShellExec( $cmd, $retval );
 702                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 703                         if ( $x != 1 ) {
 704                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 705                                 return null;
 706                         }
 707                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 708                         return $matches[1];
 709                 }
 710                 return $cache;
 711         }
 712
 713         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 714                 imageinterlace( $dst_image );
 715                 imagejpeg( $dst_image, $thumbPath, 95 );
 716         }
 717
 718         /**
 719          * On supporting image formats, try to read out the low-level orientation
 720          * of the file and return the angle that the file needs to be rotated to
 721          * be viewed.
 722          *
 723          * This information is only useful when manipulating the original file;
 724          * the width and height we normally work with is logical, and will match
 725          * any produced output views.
 726          *
 727          * The base BitmapHandler doesn't understand any metadata formats, so this
 728          * is left up to child classes to implement.
 729          *
 730          * @param $file File
 731          * @return int 0, 90, 180 or 270
 732          */
 733         public function getRotation( $file ) {
 734                 return 0;
 735         }
 736
 737         /**
 738          * Returns whether the current scaler supports rotation (im and gd do)
 739          *
 740          * @return bool
 741          */
 742         public static function canRotate() {
 743                 $scaler = self::getScalerType( null, false );
 744                 switch ( $scaler ) {
 745                         case 'im':
 746                                 # ImageMagick supports autorotation
 747                                 return true;
 748                         case 'imext':
 749                                 # Imagick::rotateImage
 750                                 return true;
 751                         case 'gd':
 752                                 # GD's imagerotate function is used to rotate images, but not
 753                                 # all precompiled PHP versions have that function
 754                                 return function_exists( 'imagerotate' );
 755                         default:
 756                                 # Other scalers don't support rotation
 757                                 return false;
 758                 }
 759         }
 760
 761         /**
 762          * Rerurns whether the file needs to be rendered. Returns true if the
 763          * file requires rotation and we are able to rotate it.
 764          *
 765          * @param $file File
 766          * @return bool
 767          */
 768         public function mustRender( $file ) {
 769                 return self::canRotate() && $this->getRotation( $file ) != 0;
 770         }
 771 }