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 TransformationalImageHandler {
  30
  31         /**
  32          * Returns which scaler type should be used. Creates parent directories
  33          * for $dstPath and returns 'client' on error
  34          *
  35          * @param string $dstPath
  36          * @param bool $checkDstPath
  37          * @return string|Callable One of client, im, custom, gd, imext or an array( object, method )
  38          */
  39         protected function getScalerType( $dstPath, $checkDstPath = true ) {
  40                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
  41
  42                 if ( !$dstPath && $checkDstPath ) {
  43                         # No output path available, client side scaling only
  44                         $scaler = 'client';
  45                 } elseif ( !$wgUseImageResize ) {
  46                         $scaler = 'client';
  47                 } elseif ( $wgUseImageMagick ) {
  48                         $scaler = 'im';
  49                 } elseif ( $wgCustomConvertCommand ) {
  50                         $scaler = 'custom';
  51                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
  52                         $scaler = 'gd';
  53                 } elseif ( class_exists( 'Imagick' ) ) {
  54                         $scaler = 'imext';
  55                 } else {
  56                         $scaler = 'client';
  57                 }
  58
  59                 return $scaler;
  60         }
  61
  62         public function makeParamString( $params ) {
  63                 $res = parent::makeParamString( $params );
  64                 if ( isset( $params['interlace'] ) && $params['interlace'] ) {
  65                         return "interlaced-{$res}";
  66                 } else {
  67                         return $res;
  68                 }
  69         }
  70
  71         public function parseParamString( $str ) {
  72                 $remainder = preg_replace( '/^interlaced-/', '', $str );
  73                 $params = parent::parseParamString( $remainder );
  74                 if ( $params === false ) {
  75                         return false;
  76                 }
  77                 $params['interlace'] = $str !== $remainder;
  78                 return $params;
  79         }
  80
  81         public function validateParam( $name, $value ) {
  82                 if ( $name === 'interlace' ) {
  83                         return $value === false || $value === true;
  84                 } else {
  85                         return parent::validateParam( $name, $value );
  86                 }
  87         }
  88
  89         /**
  90          * @param File $image
  91          * @param array $params
  92          * @return bool
  93          */
  94         function normaliseParams( $image, &$params ) {
  95                 global $wgMaxInterlacingAreas;
  96                 if ( !parent::normaliseParams( $image, $params ) ) {
  97                         return false;
  98                 }
  99                 $mimeType = $image->getMimeType();
 100                 $interlace = isset( $params['interlace'] ) && $params['interlace']
 101                         && isset( $wgMaxInterlacingAreas[$mimeType] )
 102                         && $this->getImageArea( $image ) <= $wgMaxInterlacingAreas[$mimeType];
 103                 $params['interlace'] = $interlace;
 104                 return true;
 105         }
 106
 107         /**
 108          * Transform an image using ImageMagick
 109          *
 110          * @param File $image File associated with this thumbnail
 111          * @param array $params Array with scaler params
 112          *
 113          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 114          */
 115         protected function transformImageMagick( $image, $params ) {
 116                 # use ImageMagick
 117                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
 118                         $wgImageMagickTempDir, $wgImageMagickConvertCommand, $wgMaxInterlacingAreas;
 119
 120                 $quality = [];
 121                 $sharpen = [];
 122                 $scene = false;
 123                 $animation_pre = [];
 124                 $animation_post = [];
 125                 $decoderHint = [];
 126
 127                 if ( $params['mimeType'] == 'image/jpeg' ) {
 128                         $qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
 129                         $quality = [ '-quality', $qualityVal ?: '80' ]; // 80%
 130                         if ( $params['interlace'] ) {
 131                                 $animation_post = [ '-interlace', 'JPEG' ];
 132                         }
 133                         # Sharpening, see bug 6193
 134                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 135                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 136                                 < $wgSharpenReductionThreshold
 137                         ) {
 138                                 $sharpen = [ '-sharpen', $wgSharpenParameter ];
 139                         }
 140                         if ( version_compare( $this->getMagickVersion(), "6.5.6" ) >= 0 ) {
 141                                 // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 142                                 $decoderHint = [ '-define', "jpeg:size={$params['physicalDimensions']}" ];
 143                         }
 144                 } elseif ( $params['mimeType'] == 'image/png' ) {
 145                         $quality = [ '-quality', '95' ]; // zlib 9, adaptive filtering
 146                         if ( $params['interlace'] ) {
 147                                 $animation_post = [ '-interlace', 'PNG' ];
 148                         }
 149                 } elseif ( $params['mimeType'] == 'image/webp' ) {
 150                         $quality = [ '-quality', '95' ]; // zlib 9, adaptive filtering
 151                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 152                         if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 153                                 // Extract initial frame only; we're so big it'll
 154                                 // be a total drag. :P
 155                                 $scene = 0;
 156                         } elseif ( $this->isAnimatedImage( $image ) ) {
 157                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 158                                 $animation_pre = [ '-coalesce' ];
 159                                 // We optimize the output, but -optimize is broken,
 160                                 // use optimizeTransparency instead (bug 11822)
 161                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 162                                         $animation_post = [ '-fuzz', '5%', '-layers', 'optimizeTransparency' ];
 163                                 }
 164                         }
 165                         if ( $params['interlace'] && version_compare( $this->getMagickVersion(), "6.3.4" ) >= 0
 166                                 && !$this->isAnimatedImage( $image ) ) { // interlacing animated GIFs is a bad idea
 167                                 $animation_post[] = '-interlace';
 168                                 $animation_post[] = 'GIF';
 169                         }
 170                 } elseif ( $params['mimeType'] == 'image/x-xcf' ) {
 171                         // Before merging layers, we need to set the background
 172                         // to be transparent to preserve alpha, as -layers merge
 173                         // merges all layers on to a canvas filled with the
 174                         // background colour. After merging we reset the background
 175                         // to be white for the default background colour setting
 176                         // in the PNG image (which is used in old IE)
 177                         $animation_pre = [
 178                                 '-background', 'transparent',
 179                                 '-layers', 'merge',
 180                                 '-background', 'white',
 181                         ];
 182                         MediaWiki\suppressWarnings();
 183                         $xcfMeta = unserialize( $image->getMetadata() );
 184                         MediaWiki\restoreWarnings();
 185                         if ( $xcfMeta
 186                                 && isset( $xcfMeta['colorType'] )
 187                                 && $xcfMeta['colorType'] === 'greyscale-alpha'
 188                                 && version_compare( $this->getMagickVersion(), "6.8.9-3" ) < 0
 189                         ) {
 190                                 // bug 66323 - Greyscale images not rendered properly.
 191                                 // So only take the "red" channel.
 192                                 $channelOnly = [ '-channel', 'R', '-separate' ];
 193                                 $animation_pre = array_merge( $animation_pre, $channelOnly );
 194                         }
 195                 }
 196
 197                 // Use one thread only, to avoid deadlock bugs on OOM
 198                 $env = [ 'OMP_NUM_THREADS' => 1 ];
 199                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 200                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 201                 }
 202
 203                 $rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
 204                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 205
 206                 $cmd = call_user_func_array( 'wfEscapeShellArg', array_merge(
 207                         [ $wgImageMagickConvertCommand ],
 208                         $quality,
 209                         // Specify white background color, will be used for transparent images
 210                         // in Internet Explorer/Windows instead of default black.
 211                         [ '-background', 'white' ],
 212                         $decoderHint,
 213                         [ $this->escapeMagickInput( $params['srcPath'], $scene ) ],
 214                         $animation_pre,
 215                         // For the -thumbnail option a "!" is needed to force exact size,
 216                         // or ImageMagick may decide your ratio is wrong and slice off
 217                         // a pixel.
 218                         [ '-thumbnail', "{$width}x{$height}!" ],
 219                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 220                         ( $params['comment'] !== ''
 221                                 ? [ '-set', 'comment', $this->escapeMagickProperty( $params['comment'] ) ]
 222                                 : [] ),
 223                         // T108616: Avoid exposure of local file path
 224                         [ '+set', 'Thumb::URI' ],
 225                         [ '-depth', 8 ],
 226                         $sharpen,
 227                         [ '-rotate', "-$rotation" ],
 228                         $animation_post,
 229                         [ $this->escapeMagickOutput( $params['dstPath'] ) ] ) );
 230
 231                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 232                 $retval = 0;
 233                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 234
 235                 if ( $retval !== 0 ) {
 236                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 237
 238                         return $this->getMediaTransformError( $params, "$err\nError code: $retval" );
 239                 }
 240
 241                 return false; # No error
 242         }
 243
 244         /**
 245          * Transform an image using the Imagick PHP extension
 246          *
 247          * @param File $image File associated with this thumbnail
 248          * @param array $params Array with scaler params
 249          *
 250          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 251          */
 252         protected function transformImageMagickExt( $image, $params ) {
 253                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
 254                         $wgMaxInterlacingAreas;
 255
 256                 try {
 257                         $im = new Imagick();
 258                         $im->readImage( $params['srcPath'] );
 259
 260                         if ( $params['mimeType'] == 'image/jpeg' ) {
 261                                 // Sharpening, see bug 6193
 262                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 263                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 264                                         < $wgSharpenReductionThreshold
 265                                 ) {
 266                                         // Hack, since $wgSharpenParameter is written specifically for the command line convert
 267                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 268                                         $im->sharpenImage( $radius, $sigma );
 269                                 }
 270                                 $qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
 271                                 $im->setCompressionQuality( $qualityVal ?: 80 );
 272                                 if ( $params['interlace'] ) {
 273                                         $im->setInterlaceScheme( Imagick::INTERLACE_JPEG );
 274                                 }
 275                         } elseif ( $params['mimeType'] == 'image/png' ) {
 276                                 $im->setCompressionQuality( 95 );
 277                                 if ( $params['interlace'] ) {
 278                                         $im->setInterlaceScheme( Imagick::INTERLACE_PNG );
 279                                 }
 280                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 281                                 if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 282                                         // Extract initial frame only; we're so big it'll
 283                                         // be a total drag. :P
 284                                         $im->setImageScene( 0 );
 285                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 286                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 287                                         $im = $im->coalesceImages();
 288                                 }
 289                                 // GIF interlacing is only available since 6.3.4
 290                                 $v = Imagick::getVersion();
 291                                 preg_match( '/ImageMagick ([0-9]+\.[0-9]+\.[0-9]+)/', $v['versionString'], $v );
 292
 293                                 if ( $params['interlace'] && version_compare( $v[1], '6.3.4' ) >= 0 ) {
 294                                         $im->setInterlaceScheme( Imagick::INTERLACE_GIF );
 295                                 }
 296                         }
 297
 298                         $rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
 299                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 300
 301                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 302
 303                         // Call Imagick::thumbnailImage on each frame
 304                         foreach ( $im as $i => $frame ) {
 305                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 306                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 307                                 }
 308                         }
 309                         $im->setImageDepth( 8 );
 310
 311                         if ( $rotation ) {
 312                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 313                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 314                                 }
 315                         }
 316
 317                         if ( $this->isAnimatedImage( $image ) ) {
 318                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 319                                 // This is broken somehow... can't find out how to fix it
 320                                 $result = $im->writeImages( $params['dstPath'], true );
 321                         } else {
 322                                 $result = $im->writeImage( $params['dstPath'] );
 323                         }
 324                         if ( !$result ) {
 325                                 return $this->getMediaTransformError( $params,
 326                                         "Unable to write thumbnail to {$params['dstPath']}" );
 327                         }
 328                 } catch ( ImagickException $e ) {
 329                         return $this->getMediaTransformError( $params, $e->getMessage() );
 330                 }
 331
 332                 return false;
 333         }
 334
 335         /**
 336          * Transform an image using a custom command
 337          *
 338          * @param File $image File associated with this thumbnail
 339          * @param array $params Array with scaler params
 340          *
 341          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 342          */
 343         protected function transformCustom( $image, $params ) {
 344                 # Use a custom convert command
 345                 global $wgCustomConvertCommand;
 346
 347                 # Variables: %s %d %w %h
 348                 $src = wfEscapeShellArg( $params['srcPath'] );
 349                 $dst = wfEscapeShellArg( $params['dstPath'] );
 350                 $cmd = $wgCustomConvertCommand;
 351                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 352                 $cmd = str_replace( '%h', wfEscapeShellArg( $params['physicalHeight'] ),
 353                         str_replace( '%w', wfEscapeShellArg( $params['physicalWidth'] ), $cmd ) ); # Size
 354                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 355                 $retval = 0;
 356                 $err = wfShellExecWithStderr( $cmd, $retval );
 357
 358                 if ( $retval !== 0 ) {
 359                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 360
 361                         return $this->getMediaTransformError( $params, $err );
 362                 }
 363
 364                 return false; # No error
 365         }
 366
 367         /**
 368          * Transform an image using the built in GD library
 369          *
 370          * @param File $image File associated with this thumbnail
 371          * @param array $params Array with scaler params
 372          *
 373          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 374          */
 375         protected function transformGd( $image, $params ) {
 376                 # Use PHP's builtin GD library functions.
 377                 # First find out what kind of file this is, and select the correct
 378                 # input routine for this.
 379
 380                 $typemap = [
 381                         'image/gif' => [ 'imagecreatefromgif', 'palette', false, 'imagegif' ],
 382                         'image/jpeg' => [ 'imagecreatefromjpeg', 'truecolor', true,
 383                                 [ __CLASS__, 'imageJpegWrapper' ] ],
 384                         'image/png' => [ 'imagecreatefrompng', 'bits', false, 'imagepng' ],
 385                         'image/vnd.wap.wbmp' => [ 'imagecreatefromwbmp', 'palette', false, 'imagewbmp' ],
 386                         'image/xbm' => [ 'imagecreatefromxbm', 'palette', false, 'imagexbm' ],
 387                 ];
 388
 389                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 390                         $err = 'Image type not supported';
 391                         wfDebug( "$err\n" );
 392                         $errMsg = wfMessage( 'thumbnail_image-type' )->text();
 393
 394                         return $this->getMediaTransformError( $params, $errMsg );
 395                 }
 396                 list( $loader, $colorStyle, $useQuality, $saveType ) = $typemap[$params['mimeType']];
 397
 398                 if ( !function_exists( $loader ) ) {
 399                         $err = "Incomplete GD library configuration: missing function $loader";
 400                         wfDebug( "$err\n" );
 401                         $errMsg = wfMessage( 'thumbnail_gd-library', $loader )->text();
 402
 403                         return $this->getMediaTransformError( $params, $errMsg );
 404                 }
 405
 406                 if ( !file_exists( $params['srcPath'] ) ) {
 407                         $err = "File seems to be missing: {$params['srcPath']}";
 408                         wfDebug( "$err\n" );
 409                         $errMsg = wfMessage( 'thumbnail_image-missing', $params['srcPath'] )->text();
 410
 411                         return $this->getMediaTransformError( $params, $errMsg );
 412                 }
 413
 414                 $src_image = call_user_func( $loader, $params['srcPath'] );
 415
 416                 $rotation = function_exists( 'imagerotate' ) && !isset( $params['disableRotation'] ) ?
 417                         $this->getRotation( $image ) :
 418                         0;
 419                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 420                 $dst_image = imagecreatetruecolor( $width, $height );
 421
 422                 // Initialise the destination image to transparent instead of
 423                 // the default solid black, to support PNG and GIF transparency nicely
 424                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 425                 imagecolortransparent( $dst_image, $background );
 426                 imagealphablending( $dst_image, false );
 427
 428                 if ( $colorStyle == 'palette' ) {
 429                         // Don't resample for paletted GIF images.
 430                         // It may just uglify them, and completely breaks transparency.
 431                         imagecopyresized( $dst_image, $src_image,
 432                                 0, 0, 0, 0,
 433                                 $width, $height,
 434                                 imagesx( $src_image ), imagesy( $src_image ) );
 435                 } else {
 436                         imagecopyresampled( $dst_image, $src_image,
 437                                 0, 0, 0, 0,
 438                                 $width, $height,
 439                                 imagesx( $src_image ), imagesy( $src_image ) );
 440                 }
 441
 442                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 443                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 444                         imagedestroy( $dst_image );
 445                         $dst_image = $rot_image;
 446                 }
 447
 448                 imagesavealpha( $dst_image, true );
 449
 450                 $funcParams = [ $dst_image, $params['dstPath'] ];
 451                 if ( $useQuality && isset( $params['quality'] ) ) {
 452                         $funcParams[] = $params['quality'];
 453                 }
 454                 call_user_func_array( $saveType, $funcParams );
 455
 456                 imagedestroy( $dst_image );
 457                 imagedestroy( $src_image );
 458
 459                 return false; # No error
 460         }
 461
 462         /**
 463          * Callback for transformGd when transforming jpeg images.
 464          */
 465         // FIXME: transformImageMagick() & transformImageMagickExt() uses JPEG quality 80, here it's 95?
 466         static function imageJpegWrapper( $dst_image, $thumbPath, $quality = 95 ) {
 467                 imageinterlace( $dst_image );
 468                 imagejpeg( $dst_image, $thumbPath, $quality );
 469         }
 470
 471         /**
 472          * Returns whether the current scaler supports rotation (im and gd do)
 473          *
 474          * @return bool
 475          */
 476         public function canRotate() {
 477                 $scaler = $this->getScalerType( null, false );
 478                 switch ( $scaler ) {
 479                         case 'im':
 480                                 # ImageMagick supports autorotation
 481                                 return true;
 482                         case 'imext':
 483                                 # Imagick::rotateImage
 484                                 return true;
 485                         case 'gd':
 486                                 # GD's imagerotate function is used to rotate images, but not
 487                                 # all precompiled PHP versions have that function
 488                                 return function_exists( 'imagerotate' );
 489                         default:
 490                                 # Other scalers don't support rotation
 491                                 return false;
 492                 }
 493         }
 494
 495         /**
 496          * @see $wgEnableAutoRotation
 497          * @return bool Whether auto rotation is enabled
 498          */
 499         public function autoRotateEnabled() {
 500                 global $wgEnableAutoRotation;
 501
 502                 if ( $wgEnableAutoRotation === null ) {
 503                         // Only enable auto-rotation when we actually can
 504                         return $this->canRotate();
 505                 }
 506
 507                 return $wgEnableAutoRotation;
 508         }
 509
 510         /**
 511          * @param File $file
 512          * @param array $params Rotate parameters.
 513          *   'rotation' clockwise rotation in degrees, allowed are multiples of 90
 514          * @since 1.21
 515          * @return bool
 516          */
 517         public function rotate( $file, $params ) {
 518                 global $wgImageMagickConvertCommand;
 519
 520                 $rotation = ( $params['rotation'] + $this->getRotation( $file ) ) % 360;
 521                 $scene = false;
 522
 523                 $scaler = $this->getScalerType( null, false );
 524                 switch ( $scaler ) {
 525                         case 'im':
 526                                 $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . " " .
 527                                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 528                                         " -rotate " . wfEscapeShellArg( "-$rotation" ) . " " .
 529                                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) );
 530                                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 531                                 $retval = 0;
 532                                 $err = wfShellExecWithStderr( $cmd, $retval );
 533                                 if ( $retval !== 0 ) {
 534                                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 535
 536                                         return new MediaTransformError( 'thumbnail_error', 0, 0, $err );
 537                                 }
 538
 539                                 return false;
 540                         case 'imext':
 541                                 $im = new Imagick();
 542                                 $im->readImage( $params['srcPath'] );
 543                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 544                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 545                                                 "Error rotating $rotation degrees" );
 546                                 }
 547                                 $result = $im->writeImage( $params['dstPath'] );
 548                                 if ( !$result ) {
 549                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 550                                                 "Unable to write image to {$params['dstPath']}" );
 551                                 }
 552
 553                                 return false;
 554                         default:
 555                                 return new MediaTransformError( 'thumbnail_error', 0, 0,
 556                                         "$scaler rotation not implemented" );
 557                 }
 558         }
 559 }