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                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 171                                 $scalerParams['clientHeight'], false );
 172                 }
 173
 174                 # Try to make a target path for the thumbnail
 175                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 176                         wfDebug( __METHOD__ . ": Unable to create thumbnail destination directory, falling back to client scaling\n" );
 177                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 178                 }
 179
 180                 # Transform functions and binaries need a FS source file
 181                 $scalerParams['srcPath'] = $image->getLocalRefPath();
 182
 183                 # Try a hook
 184                 $mto = null;
 185                 wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
 186                 if ( !is_null( $mto ) ) {
 187                         wfDebug( __METHOD__ . ": Hook to BitmapHandlerTransform created an mto\n" );
 188                         $scaler = 'hookaborted';
 189                 }
 190
 191                 switch ( $scaler ) {
 192                         case 'hookaborted':
 193                                 # Handled by the hook above
 194                                 $err = $mto->isError() ? $mto : false;
 195                                 break;
 196                         case 'im':
 197                                 $err = $this->transformImageMagick( $image, $scalerParams );
 198                                 break;
 199                         case 'custom':
 200                                 $err = $this->transformCustom( $image, $scalerParams );
 201                                 break;
 202                         case 'imext':
 203                                 $err = $this->transformImageMagickExt( $image, $scalerParams );
 204                                 break;
 205                         case 'gd':
 206                         default:
 207                                 $err = $this->transformGd( $image, $scalerParams );
 208                                 break;
 209                 }
 210
 211                 # Remove the file if a zero-byte thumbnail was created, or if there was an error
 212                 $removed = $this->removeBadFile( $dstPath, (bool)$err );
 213                 if ( $err ) {
 214                         # transform returned MediaTransforError
 215                         return $err;
 216                 } elseif ( $removed ) {
 217                         # Thumbnail was zero-byte and had to be removed
 218                         return new MediaTransformError( 'thumbnail_error',
 219                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'] );
 220                 } elseif ( $mto ) {
 221                         return $mto;
 222                 } else {
 223                         return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 224                                 $scalerParams['clientHeight'], $dstPath );
 225                 }
 226         }
 227
 228         /**
 229          * Returns which scaler type should be used. Creates parent directories
 230          * for $dstPath and returns 'client' on error
 231          *
 232          * @return string client,im,custom,gd
 233          */
 234         protected static function getScalerType( $dstPath, $checkDstPath = true ) {
 235                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
 236
 237                 if ( !$dstPath && $checkDstPath ) {
 238                         # No output path available, client side scaling only
 239                         $scaler = 'client';
 240                 } elseif ( !$wgUseImageResize ) {
 241                         $scaler = 'client';
 242                 } elseif ( $wgUseImageMagick ) {
 243                         $scaler = 'im';
 244                 } elseif ( $wgCustomConvertCommand ) {
 245                         $scaler = 'custom';
 246                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
 247                         $scaler = 'gd';
 248                 } elseif ( class_exists( 'Imagick' ) ) {
 249                         $scaler = 'imext';
 250                 } else {
 251                         $scaler = 'client';
 252                 }
 253                 return $scaler;
 254         }
 255
 256         /**
 257          * Get a ThumbnailImage that respresents an image that will be scaled
 258          * client side
 259          *
 260          * @param $image File File associated with this thumbnail
 261          * @param $params array Array with scaler params
 262          * @return ThumbnailImage
 263          *
 264          * @todo fixme: no rotation support
 265          */
 266         protected function getClientScalingThumbnailImage( $image, $params ) {
 267                 return new ThumbnailImage( $image, $image->getURL(),
 268                         $params['clientWidth'], $params['clientHeight'], null );
 269         }
 270
 271         /**
 272          * Transform an image using ImageMagick
 273          *
 274          * @param $image File File associated with this thumbnail
 275          * @param $params array Array with scaler params
 276          *
 277          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 278          */
 279         protected function transformImageMagick( $image, $params ) {
 280                 # use ImageMagick
 281                 global $wgSharpenReductionThreshold, $wgSharpenParameter,
 282                         $wgMaxAnimatedGifArea,
 283                         $wgImageMagickTempDir, $wgImageMagickConvertCommand;
 284
 285                 $quality = '';
 286                 $sharpen = '';
 287                 $scene = false;
 288                 $animation_pre = '';
 289                 $animation_post = '';
 290                 $decoderHint = '';
 291                 if ( $params['mimeType'] == 'image/jpeg' ) {
 292                         $quality = "-quality 80"; // 80%
 293                         # Sharpening, see bug 6193
 294                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 295                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 296                                         < $wgSharpenReductionThreshold ) {
 297                                 $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 298                         }
 299                         if ( version_compare( $this->getMagickVersion(), "6.5.6" ) >= 0 ) {
 300                                 // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 301                                 $decoderHint = "-define jpeg:size={$params['physicalDimensions']}";
 302                         }
 303
 304                 } elseif ( $params['mimeType'] == 'image/png' ) {
 305                         $quality = "-quality 95"; // zlib 9, adaptive filtering
 306
 307                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 308                         if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 309                                 // Extract initial frame only; we're so big it'll
 310                                 // be a total drag. :P
 311                                 $scene = 0;
 312
 313                         } elseif ( $this->isAnimatedImage( $image ) ) {
 314                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 315                                 $animation_pre = '-coalesce';
 316                                 // We optimize the output, but -optimize is broken,
 317                                 // use optimizeTransparency instead (bug 11822)
 318                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 319                                         $animation_post = '-fuzz 5% -layers optimizeTransparency';
 320                                 }
 321                         }
 322                 } elseif ( $params['mimeType'] == 'image/x-xcf' ) {
 323                         $animation_post = '-layers merge';
 324                 }
 325
 326                 // Use one thread only, to avoid deadlock bugs on OOM
 327                 $env = array( 'OMP_NUM_THREADS' => 1 );
 328                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 329                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 330                 }
 331
 332                 $rotation = $this->getRotation( $image );
 333                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 334
 335                 $cmd  =
 336                         wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 337                         // Specify white background color, will be used for transparent images
 338                         // in Internet Explorer/Windows instead of default black.
 339                         " {$quality} -background white" .
 340                         " {$decoderHint} " .
 341                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 342                         " {$animation_pre}" .
 343                         // For the -thumbnail option a "!" is needed to force exact size,
 344                         // or ImageMagick may decide your ratio is wrong and slice off
 345                         // a pixel.
 346                         " -thumbnail " . wfEscapeShellArg( "{$width}x{$height}!" ) .
 347                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 348                         ( $params['comment'] !== ''
 349                                 ? " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) )
 350                                 : '' ) .
 351                         " -depth 8 $sharpen " .
 352                         " -rotate -$rotation " .
 353                         " {$animation_post} " .
 354                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) ) . " 2>&1";
 355
 356                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 357                 wfProfileIn( 'convert' );
 358                 $retval = 0;
 359                 $err = wfShellExec( $cmd, $retval, $env );
 360                 wfProfileOut( 'convert' );
 361
 362                 if ( $retval !== 0 ) {
 363                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 364                         return $this->getMediaTransformError( $params, $err );
 365                 }
 366
 367                 return false; # No error
 368         }
 369
 370         /**
 371          * Transform an image using the Imagick PHP extension
 372          *
 373          * @param $image File File associated with this thumbnail
 374          * @param $params array Array with scaler params
 375          *
 376          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 377          */
 378         protected function transformImageMagickExt( $image, $params ) {
 379                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea;
 380
 381                 try {
 382                         $im = new Imagick();
 383                         $im->readImage( $params['srcPath'] );
 384
 385                         if ( $params['mimeType'] == 'image/jpeg' ) {
 386                                 // Sharpening, see bug 6193
 387                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 388                                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 389                                                 < $wgSharpenReductionThreshold ) {
 390                                         // Hack, since $wgSharpenParamater is written specifically for the command line convert
 391                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 392                                         $im->sharpenImage( $radius, $sigma );
 393                                 }
 394                                 $im->setCompressionQuality( 80 );
 395                         } elseif( $params['mimeType'] == 'image/png' ) {
 396                                 $im->setCompressionQuality( 95 );
 397                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 398                                 if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 399                                         // Extract initial frame only; we're so big it'll
 400                                         // be a total drag. :P
 401                                         $im->setImageScene( 0 );
 402                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 403                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 404                                         $im = $im->coalesceImages();
 405                                 }
 406                         }
 407
 408                         $rotation = $this->getRotation( $image );
 409                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 410
 411                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 412
 413                         // Call Imagick::thumbnailImage on each frame
 414                         foreach ( $im as $i => $frame ) {
 415                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 416                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 417                                 }
 418                         }
 419                         $im->setImageDepth( 8 );
 420
 421                         if ( $rotation ) {
 422                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 423                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 424                                 }
 425                         }
 426
 427                         if ( $this->isAnimatedImage( $image ) ) {
 428                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 429                                 // This is broken somehow... can't find out how to fix it
 430                                 $result = $im->writeImages( $params['dstPath'], true );
 431                         } else {
 432                                 $result = $im->writeImage( $params['dstPath'] );
 433                         }
 434                         if ( !$result ) {
 435                                 return $this->getMediaTransformError( $params,
 436                                         "Unable to write thumbnail to {$params['dstPath']}" );
 437                         }
 438
 439                 } catch ( ImagickException $e ) {
 440                         return $this->getMediaTransformError( $params, $e->getMessage() );
 441                 }
 442
 443                 return false;
 444
 445         }
 446
 447         /**
 448          * Transform an image using a custom command
 449          *
 450          * @param $image File File associated with this thumbnail
 451          * @param $params array Array with scaler params
 452          *
 453          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 454          */
 455         protected function transformCustom( $image, $params ) {
 456                 # Use a custom convert command
 457                 global $wgCustomConvertCommand;
 458
 459                 # Variables: %s %d %w %h
 460                 $src = wfEscapeShellArg( $params['srcPath'] );
 461                 $dst = wfEscapeShellArg( $params['dstPath'] );
 462                 $cmd = $wgCustomConvertCommand;
 463                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 464                 $cmd = str_replace( '%h', $params['physicalHeight'],
 465                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 466                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 467                 wfProfileIn( 'convert' );
 468                 $retval = 0;
 469                 $err = wfShellExec( $cmd, $retval );
 470                 wfProfileOut( 'convert' );
 471
 472                 if ( $retval !== 0 ) {
 473                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 474                         return $this->getMediaTransformError( $params, $err );
 475                 }
 476                 return false; # No error
 477         }
 478
 479         /**
 480          * Log an error that occured in an external process
 481          *
 482          * @param $retval int
 483          * @param $err int
 484          * @param $cmd string
 485          */
 486         protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
 487                 wfDebugLog( 'thumbnail',
 488                         sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 489                                         wfHostname(), $retval, trim( $err ), $cmd ) );
 490         }
 491         /**
 492          * Get a MediaTransformError with error 'thumbnail_error'
 493          *
 494          * @param $params array Parameter array as passed to the transform* functions
 495          * @param $errMsg string Error message
 496          * @return MediaTransformError
 497          */
 498         public function getMediaTransformError( $params, $errMsg ) {
 499                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 500                                         $params['clientHeight'], $errMsg );
 501         }
 502
 503         /**
 504          * Transform an image using the built in GD library
 505          *
 506          * @param $image File File associated with this thumbnail
 507          * @param $params array Array with scaler params
 508          *
 509          * @return MediaTransformError Error object if error occured, false (=no error) otherwise
 510          */
 511         protected function transformGd( $image, $params ) {
 512                 # Use PHP's builtin GD library functions.
 513                 #
 514                 # First find out what kind of file this is, and select the correct
 515                 # input routine for this.
 516
 517                 $typemap = array(
 518                         'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
 519                         'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( __CLASS__, 'imageJpegWrapper' ) ),
 520                         'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
 521                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
 522                         'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
 523                 );
 524                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 525                         $err = 'Image type not supported';
 526                         wfDebug( "$err\n" );
 527                         $errMsg = wfMsg( 'thumbnail_image-type' );
 528                         return $this->getMediaTransformError( $params, $errMsg );
 529                 }
 530                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 531
 532                 if ( !function_exists( $loader ) ) {
 533                         $err = "Incomplete GD library configuration: missing function $loader";
 534                         wfDebug( "$err\n" );
 535                         $errMsg = wfMsg( 'thumbnail_gd-library', $loader );
 536                         return $this->getMediaTransformError( $params, $errMsg );
 537                 }
 538
 539                 if ( !file_exists( $params['srcPath'] ) ) {
 540                         $err = "File seems to be missing: {$params['srcPath']}";
 541                         wfDebug( "$err\n" );
 542                         $errMsg = wfMsg( 'thumbnail_image-missing', $params['srcPath'] );
 543                         return $this->getMediaTransformError( $params, $errMsg );
 544                 }
 545
 546                 $src_image = call_user_func( $loader, $params['srcPath'] );
 547
 548                 $rotation = function_exists( 'imagerotate' ) ? $this->getRotation( $image ) : 0;
 549                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 550                 $dst_image = imagecreatetruecolor( $width, $height );
 551
 552                 // Initialise the destination image to transparent instead of
 553                 // the default solid black, to support PNG and GIF transparency nicely
 554                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 555                 imagecolortransparent( $dst_image, $background );
 556                 imagealphablending( $dst_image, false );
 557
 558                 if ( $colorStyle == 'palette' ) {
 559                         // Don't resample for paletted GIF images.
 560                         // It may just uglify them, and completely breaks transparency.
 561                         imagecopyresized( $dst_image, $src_image,
 562                                 0, 0, 0, 0,
 563                                 $width, $height,
 564                                 imagesx( $src_image ), imagesy( $src_image ) );
 565                 } else {
 566                         imagecopyresampled( $dst_image, $src_image,
 567                                 0, 0, 0, 0,
 568                                 $width, $height,
 569                                 imagesx( $src_image ), imagesy( $src_image ) );
 570                 }
 571
 572                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 573                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 574                         imagedestroy( $dst_image );
 575                         $dst_image = $rot_image;
 576                 }
 577
 578                 imagesavealpha( $dst_image, true );
 579
 580                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 581                 imagedestroy( $dst_image );
 582                 imagedestroy( $src_image );
 583
 584                 return false; # No error
 585         }
 586
 587         /**
 588          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 589          * See InterpretImageProperties() in magick/property.c
 590          * @return mixed|string
 591          */
 592         function escapeMagickProperty( $s ) {
 593                 // Double the backslashes
 594                 $s = str_replace( '\\', '\\\\', $s );
 595                 // Double the percents
 596                 $s = str_replace( '%', '%%', $s );
 597                 // Escape initial - or @
 598                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 599                         $s = '\\' . $s;
 600                 }
 601                 return $s;
 602         }
 603
 604         /**
 605          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 606          * and GetPathComponent() in magick/utility.c.
 607          *
 608          * This won't work with an initial ~ or @, so input files should be prefixed
 609          * with the directory name.
 610          *
 611          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 612          * it's broken in a way that doesn't involve trying to convert every file
 613          * in a directory, so we're better off escaping and waiting for the bugfix
 614          * to filter down to users.
 615          *
 616          * @param $path string The file path
 617          * @param $scene string The scene specification, or false if there is none
 618          * @return string
 619          */
 620         function escapeMagickInput( $path, $scene = false ) {
 621                 # Die on initial metacharacters (caller should prepend path)
 622                 $firstChar = substr( $path, 0, 1 );
 623                 if ( $firstChar === '~' || $firstChar === '@' ) {
 624                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 625                 }
 626
 627                 # Escape glob chars
 628                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 629
 630                 return $this->escapeMagickPath( $path, $scene );
 631         }
 632
 633         /**
 634          * Escape a string for ImageMagick's output filename. See
 635          * InterpretImageFilename() in magick/image.c.
 636          * @return string
 637          */
 638         function escapeMagickOutput( $path, $scene = false ) {
 639                 $path = str_replace( '%', '%%', $path );
 640                 return $this->escapeMagickPath( $path, $scene );
 641         }
 642
 643         /**
 644          * Armour a string against ImageMagick's GetPathComponent(). This is a
 645          * helper function for escapeMagickInput() and escapeMagickOutput().
 646          *
 647          * @param $path string The file path
 648          * @param $scene string The scene specification, or false if there is none
 649          * @return string
 650          */
 651         protected function escapeMagickPath( $path, $scene = false ) {
 652                 # Die on format specifiers (other than drive letters). The regex is
 653                 # meant to match all the formats you get from "convert -list format"
 654                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 655                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 656                                 // OK, it's a drive letter
 657                                 // ImageMagick has a similar exception, see IsMagickConflict()
 658                         } else {
 659                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 660                         }
 661                 }
 662
 663                 # If there are square brackets, add a do-nothing scene specification
 664                 # to force a literal interpretation
 665                 if ( $scene === false ) {
 666                         if ( strpos( $path, '[' ) !== false ) {
 667                                 $path .= '[0--1]';
 668                         }
 669                 } else {
 670                         $path .= "[$scene]";
 671                 }
 672                 return $path;
 673         }
 674
 675         /**
 676          * Retrieve the version of the installed ImageMagick
 677          * You can use PHPs version_compare() to use this value
 678          * Value is cached for one hour.
 679          * @return String representing the IM version.
 680          */
 681         protected function getMagickVersion() {
 682                 global $wgMemc;
 683
 684                 $cache = $wgMemc->get( "imagemagick-version" );
 685                 if ( !$cache ) {
 686                         global $wgImageMagickConvertCommand;
 687                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 688                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 689                         $retval = '';
 690                         $return = wfShellExec( $cmd, $retval );
 691                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 692                         if ( $x != 1 ) {
 693                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 694                                 return null;
 695                         }
 696                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 697                         return $matches[1];
 698                 }
 699                 return $cache;
 700         }
 701
 702         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 703                 imageinterlace( $dst_image );
 704                 imagejpeg( $dst_image, $thumbPath, 95 );
 705         }
 706
 707         /**
 708          * On supporting image formats, try to read out the low-level orientation
 709          * of the file and return the angle that the file needs to be rotated to
 710          * be viewed.
 711          *
 712          * This information is only useful when manipulating the original file;
 713          * the width and height we normally work with is logical, and will match
 714          * any produced output views.
 715          *
 716          * The base BitmapHandler doesn't understand any metadata formats, so this
 717          * is left up to child classes to implement.
 718          *
 719          * @param $file File
 720          * @return int 0, 90, 180 or 270
 721          */
 722         public function getRotation( $file ) {
 723                 return 0;
 724         }
 725
 726         /**
 727          * Returns whether the current scaler supports rotation (im and gd do)
 728          *
 729          * @return bool
 730          */
 731         public static function canRotate() {
 732                 $scaler = self::getScalerType( null, false );
 733                 switch ( $scaler ) {
 734                         case 'im':
 735                                 # ImageMagick supports autorotation
 736                                 return true;
 737                         case 'imext':
 738                                 # Imagick::rotateImage
 739                                 return true;
 740                         case 'gd':
 741                                 # GD's imagerotate function is used to rotate images, but not
 742                                 # all precompiled PHP versions have that function
 743                                 return function_exists( 'imagerotate' );
 744                         default:
 745                                 # Other scalers don't support rotation
 746                                 return false;
 747                 }
 748         }
 749
 750         /**
 751          * Rerurns whether the file needs to be rendered. Returns true if the
 752          * file requires rotation and we are able to rotate it.
 753          *
 754          * @param $file File
 755          * @return bool
 756          */
 757         public function mustRender( $file ) {
 758                 return self::canRotate() && $this->getRotation( $file ) != 0;
 759         }
 760 }