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 File $image
  32          * @param array $params 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(
  61                         'BitmapHandlerCheckImageArea',
  62                         array( $image, &$params, &$checkImageAreaHookResult )
  63                 );
  64
  65                 if ( is_null( $checkImageAreaHookResult ) ) {
  66                         global $wgMaxImageArea;
  67
  68                         if ( $srcWidth * $srcHeight > $wgMaxImageArea
  69                                 && !( $image->getMimeType() == 'image/jpeg'
  70                                 && self::getScalerType( false, false ) == 'im' )
  71                         ) {
  72                                 # Only ImageMagick can efficiently downsize jpg images without loading
  73                                 # the entire file in memory
  74                                 return false;
  75                         }
  76                 } else {
  77                         return $checkImageAreaHookResult;
  78                 }
  79
  80                 return true;
  81         }
  82
  83         /**
  84          * Extracts the width/height if the image will be scaled before rotating
  85          *
  86          * This will match the physical size/aspect ratio of the original image
  87          * prior to application of the rotation -- so for a portrait image that's
  88          * stored as raw landscape with 90-degress rotation, the resulting size
  89          * will be wider than it is tall.
  90          *
  91          * @param array $params Parameters as returned by normaliseParams
  92          * @param int $rotation The rotation angle that will be applied
  93          * @return array ($width, $height) array
  94          */
  95         public function extractPreRotationDimensions( $params, $rotation ) {
  96                 if ( $rotation == 90 || $rotation == 270 ) {
  97                         # We'll resize before rotation, so swap the dimensions again
  98                         $width = $params['physicalHeight'];
  99                         $height = $params['physicalWidth'];
 100                 } else {
 101                         $width = $params['physicalWidth'];
 102                         $height = $params['physicalHeight'];
 103                 }
 104
 105                 return array( $width, $height );
 106         }
 107
 108         /**
 109          * @param File $image
 110          * @param string $dstPath
 111          * @param string $dstUrl
 112          * @param array $params
 113          * @param int $flags
 114          * @return MediaTransformError|ThumbnailImage|TransformParameterError
 115          */
 116         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 117                 if ( !$this->normaliseParams( $image, $params ) ) {
 118                         return new TransformParameterError( $params );
 119                 }
 120                 # Create a parameter array to pass to the scaler
 121                 $scalerParams = array(
 122                         # The size to which the image will be resized
 123                         'physicalWidth' => $params['physicalWidth'],
 124                         'physicalHeight' => $params['physicalHeight'],
 125                         'physicalDimensions' => "{$params['physicalWidth']}x{$params['physicalHeight']}",
 126                         # The size of the image on the page
 127                         'clientWidth' => $params['width'],
 128                         'clientHeight' => $params['height'],
 129                         # Comment as will be added to the Exif of the thumbnail
 130                         'comment' => isset( $params['descriptionUrl'] )
 131                                 ? "File source: {$params['descriptionUrl']}"
 132                                 : '',
 133                         # Properties of the original image
 134                         'srcWidth' => $image->getWidth(),
 135                         'srcHeight' => $image->getHeight(),
 136                         'mimeType' => $image->getMimeType(),
 137                         'dstPath' => $dstPath,
 138                         'dstUrl' => $dstUrl,
 139                 );
 140
 141                 # Determine scaler type
 142                 $scaler = self::getScalerType( $dstPath );
 143
 144                 wfDebug( __METHOD__ . ": creating {$scalerParams['physicalDimensions']} " .
 145                         "thumbnail at $dstPath using scaler $scaler\n" );
 146
 147                 if ( !$image->mustRender() &&
 148                         $scalerParams['physicalWidth'] == $scalerParams['srcWidth']
 149                         && $scalerParams['physicalHeight'] == $scalerParams['srcHeight']
 150                 ) {
 151
 152                         # normaliseParams (or the user) wants us to return the unscaled image
 153                         wfDebug( __METHOD__ . ": returning unscaled image\n" );
 154
 155                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 156                 }
 157
 158                 if ( $scaler == 'client' ) {
 159                         # Client-side image scaling, use the source URL
 160                         # Using the destination URL in a TRANSFORM_LATER request would be incorrect
 161                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 162                 }
 163
 164                 if ( $flags & self::TRANSFORM_LATER ) {
 165                         wfDebug( __METHOD__ . ": Transforming later per flags.\n" );
 166                         $params = array(
 167                                 'width' => $scalerParams['clientWidth'],
 168                                 'height' => $scalerParams['clientHeight']
 169                         );
 170
 171                         return new ThumbnailImage( $image, $dstUrl, false, $params );
 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 " .
 177                                 "directory, falling back to client scaling\n" );
 178
 179                         return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 180                 }
 181
 182                 # Transform functions and binaries need a FS source file
 183                 $scalerParams['srcPath'] = $image->getLocalRefPath();
 184                 if ( $scalerParams['srcPath'] === false ) { // Failed to get local copy
 185                         wfDebugLog( 'thumbnail',
 186                                 sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
 187                                         wfHostname(), $image->getName() ) );
 188
 189                         return new MediaTransformError( 'thumbnail_error',
 190                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'] );
 191                 }
 192
 193                 # Try a hook
 194                 $mto = null;
 195                 wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
 196                 if ( !is_null( $mto ) ) {
 197                         wfDebug( __METHOD__ . ": Hook to BitmapHandlerTransform created an mto\n" );
 198                         $scaler = 'hookaborted';
 199                 }
 200
 201                 switch ( $scaler ) {
 202                         case 'hookaborted':
 203                                 # Handled by the hook above
 204                                 /** @var MediaTransformOutput $mto */
 205                                 $err = $mto->isError() ? $mto : false;
 206                                 break;
 207                         case 'im':
 208                                 $err = $this->transformImageMagick( $image, $scalerParams );
 209                                 break;
 210                         case 'custom':
 211                                 $err = $this->transformCustom( $image, $scalerParams );
 212                                 break;
 213                         case 'imext':
 214                                 $err = $this->transformImageMagickExt( $image, $scalerParams );
 215                                 break;
 216                         case 'gd':
 217                         default:
 218                                 $err = $this->transformGd( $image, $scalerParams );
 219                                 break;
 220                 }
 221
 222                 # Remove the file if a zero-byte thumbnail was created, or if there was an error
 223                 $removed = $this->removeBadFile( $dstPath, (bool)$err );
 224                 if ( $err ) {
 225                         # transform returned MediaTransforError
 226                         return $err;
 227                 } elseif ( $removed ) {
 228                         # Thumbnail was zero-byte and had to be removed
 229                         return new MediaTransformError( 'thumbnail_error',
 230                                 $scalerParams['clientWidth'], $scalerParams['clientHeight'] );
 231                 } elseif ( $mto ) {
 232                         return $mto;
 233                 } else {
 234                         $params = array(
 235                                 'width' => $scalerParams['clientWidth'],
 236                                 'height' => $scalerParams['clientHeight']
 237                         );
 238
 239                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 240                 }
 241         }
 242
 243         /**
 244          * Returns which scaler type should be used. Creates parent directories
 245          * for $dstPath and returns 'client' on error
 246          *
 247          * @param string $dstPath
 248          * @param bool $checkDstPath
 249          * @return string One of client, im, custom, gd, imext
 250          */
 251         protected static function getScalerType( $dstPath, $checkDstPath = true ) {
 252                 global $wgUseImageResize, $wgUseImageMagick, $wgCustomConvertCommand;
 253
 254                 if ( !$dstPath && $checkDstPath ) {
 255                         # No output path available, client side scaling only
 256                         $scaler = 'client';
 257                 } elseif ( !$wgUseImageResize ) {
 258                         $scaler = 'client';
 259                 } elseif ( $wgUseImageMagick ) {
 260                         $scaler = 'im';
 261                 } elseif ( $wgCustomConvertCommand ) {
 262                         $scaler = 'custom';
 263                 } elseif ( function_exists( 'imagecreatetruecolor' ) ) {
 264                         $scaler = 'gd';
 265                 } elseif ( class_exists( 'Imagick' ) ) {
 266                         $scaler = 'imext';
 267                 } else {
 268                         $scaler = 'client';
 269                 }
 270
 271                 return $scaler;
 272         }
 273
 274         /**
 275          * Get a ThumbnailImage that respresents an image that will be scaled
 276          * client side
 277          *
 278          * @param File $image File associated with this thumbnail
 279          * @param array $scalerParams Array with scaler params
 280          * @return ThumbnailImage
 281          *
 282          * @todo FIXME: No rotation support
 283          */
 284         protected function getClientScalingThumbnailImage( $image, $scalerParams ) {
 285                 $params = array(
 286                         'width' => $scalerParams['clientWidth'],
 287                         'height' => $scalerParams['clientHeight']
 288                 );
 289
 290                 return new ThumbnailImage( $image, $image->getURL(), null, $params );
 291         }
 292
 293         /**
 294          * Transform an image using ImageMagick
 295          *
 296          * @param File $image File associated with this thumbnail
 297          * @param array $params Array with scaler params
 298          *
 299          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 300          */
 301         protected function transformImageMagick( $image, $params ) {
 302                 # use ImageMagick
 303                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
 304                         $wgImageMagickTempDir, $wgImageMagickConvertCommand;
 305
 306                 $quality = '';
 307                 $sharpen = '';
 308                 $scene = false;
 309                 $animation_pre = '';
 310                 $animation_post = '';
 311                 $decoderHint = '';
 312                 if ( $params['mimeType'] == 'image/jpeg' ) {
 313                         $quality = "-quality 80"; // 80%
 314                         # Sharpening, see bug 6193
 315                         if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 316                                 / ( $params['srcWidth'] + $params['srcHeight'] )
 317                                 < $wgSharpenReductionThreshold
 318                         ) {
 319                                 $sharpen = "-sharpen " . wfEscapeShellArg( $wgSharpenParameter );
 320                         }
 321                         if ( version_compare( $this->getMagickVersion(), "6.5.6" ) >= 0 ) {
 322                                 // JPEG decoder hint to reduce memory, available since IM 6.5.6-2
 323                                 $decoderHint = "-define jpeg:size={$params['physicalDimensions']}";
 324                         }
 325                 } elseif ( $params['mimeType'] == 'image/png' ) {
 326                         $quality = "-quality 95"; // zlib 9, adaptive filtering
 327
 328                 } elseif ( $params['mimeType'] == 'image/gif' ) {
 329                         if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 330                                 // Extract initial frame only; we're so big it'll
 331                                 // be a total drag. :P
 332                                 $scene = 0;
 333                         } elseif ( $this->isAnimatedImage( $image ) ) {
 334                                 // Coalesce is needed to scale animated GIFs properly (bug 1017).
 335                                 $animation_pre = '-coalesce';
 336                                 // We optimize the output, but -optimize is broken,
 337                                 // use optimizeTransparency instead (bug 11822)
 338                                 if ( version_compare( $this->getMagickVersion(), "6.3.5" ) >= 0 ) {
 339                                         $animation_post = '-fuzz 5% -layers optimizeTransparency';
 340                                 }
 341                         }
 342                 } elseif ( $params['mimeType'] == 'image/x-xcf' ) {
 343                         $animation_post = '-layers merge';
 344                 }
 345
 346                 // Use one thread only, to avoid deadlock bugs on OOM
 347                 $env = array( 'OMP_NUM_THREADS' => 1 );
 348                 if ( strval( $wgImageMagickTempDir ) !== '' ) {
 349                         $env['MAGICK_TMPDIR'] = $wgImageMagickTempDir;
 350                 }
 351
 352                 $rotation = $this->getRotation( $image );
 353                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 354
 355                 $cmd =
 356                         wfEscapeShellArg( $wgImageMagickConvertCommand ) .
 357                         // Specify white background color, will be used for transparent images
 358                         // in Internet Explorer/Windows instead of default black.
 359                         " {$quality} -background white" .
 360                         " {$decoderHint} " .
 361                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 362                         " {$animation_pre}" .
 363                         // For the -thumbnail option a "!" is needed to force exact size,
 364                         // or ImageMagick may decide your ratio is wrong and slice off
 365                         // a pixel.
 366                         " -thumbnail " . wfEscapeShellArg( "{$width}x{$height}!" ) .
 367                         // Add the source url as a comment to the thumb, but don't add the flag if there's no comment
 368                         ( $params['comment'] !== ''
 369                                 ? " -set comment " . wfEscapeShellArg( $this->escapeMagickProperty( $params['comment'] ) )
 370                                 : '' ) .
 371                         " -depth 8 $sharpen " .
 372                         " -rotate -$rotation " .
 373                         " {$animation_post} " .
 374                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) );
 375
 376                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 377                 wfProfileIn( 'convert' );
 378                 $retval = 0;
 379                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 380                 wfProfileOut( 'convert' );
 381
 382                 if ( $retval !== 0 ) {
 383                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 384
 385                         return $this->getMediaTransformError( $params, "$err\nError code: $retval" );
 386                 }
 387
 388                 return false; # No error
 389         }
 390
 391         /**
 392          * Transform an image using the Imagick PHP extension
 393          *
 394          * @param File $image File associated with this thumbnail
 395          * @param array $params Array with scaler params
 396          *
 397          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 398          */
 399         protected function transformImageMagickExt( $image, $params ) {
 400                 global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea;
 401
 402                 try {
 403                         $im = new Imagick();
 404                         $im->readImage( $params['srcPath'] );
 405
 406                         if ( $params['mimeType'] == 'image/jpeg' ) {
 407                                 // Sharpening, see bug 6193
 408                                 if ( ( $params['physicalWidth'] + $params['physicalHeight'] )
 409                                         / ( $params['srcWidth'] + $params['srcHeight'] )
 410                                         < $wgSharpenReductionThreshold
 411                                 ) {
 412                                         // Hack, since $wgSharpenParamater is written specifically for the command line convert
 413                                         list( $radius, $sigma ) = explode( 'x', $wgSharpenParameter );
 414                                         $im->sharpenImage( $radius, $sigma );
 415                                 }
 416                                 $im->setCompressionQuality( 80 );
 417                         } elseif ( $params['mimeType'] == 'image/png' ) {
 418                                 $im->setCompressionQuality( 95 );
 419                         } elseif ( $params['mimeType'] == 'image/gif' ) {
 420                                 if ( $this->getImageArea( $image ) > $wgMaxAnimatedGifArea ) {
 421                                         // Extract initial frame only; we're so big it'll
 422                                         // be a total drag. :P
 423                                         $im->setImageScene( 0 );
 424                                 } elseif ( $this->isAnimatedImage( $image ) ) {
 425                                         // Coalesce is needed to scale animated GIFs properly (bug 1017).
 426                                         $im = $im->coalesceImages();
 427                                 }
 428                         }
 429
 430                         $rotation = $this->getRotation( $image );
 431                         list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 432
 433                         $im->setImageBackgroundColor( new ImagickPixel( 'white' ) );
 434
 435                         // Call Imagick::thumbnailImage on each frame
 436                         foreach ( $im as $i => $frame ) {
 437                                 if ( !$frame->thumbnailImage( $width, $height, /* fit */ false ) ) {
 438                                         return $this->getMediaTransformError( $params, "Error scaling frame $i" );
 439                                 }
 440                         }
 441                         $im->setImageDepth( 8 );
 442
 443                         if ( $rotation ) {
 444                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 445                                         return $this->getMediaTransformError( $params, "Error rotating $rotation degrees" );
 446                                 }
 447                         }
 448
 449                         if ( $this->isAnimatedImage( $image ) ) {
 450                                 wfDebug( __METHOD__ . ": Writing animated thumbnail\n" );
 451                                 // This is broken somehow... can't find out how to fix it
 452                                 $result = $im->writeImages( $params['dstPath'], true );
 453                         } else {
 454                                 $result = $im->writeImage( $params['dstPath'] );
 455                         }
 456                         if ( !$result ) {
 457                                 return $this->getMediaTransformError( $params,
 458                                         "Unable to write thumbnail to {$params['dstPath']}" );
 459                         }
 460                 } catch ( ImagickException $e ) {
 461                         return $this->getMediaTransformError( $params, $e->getMessage() );
 462                 }
 463
 464                 return false;
 465         }
 466
 467         /**
 468          * Transform an image using a custom command
 469          *
 470          * @param File $image File associated with this thumbnail
 471          * @param array $params Array with scaler params
 472          *
 473          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 474          */
 475         protected function transformCustom( $image, $params ) {
 476                 # Use a custom convert command
 477                 global $wgCustomConvertCommand;
 478
 479                 # Variables: %s %d %w %h
 480                 $src = wfEscapeShellArg( $params['srcPath'] );
 481                 $dst = wfEscapeShellArg( $params['dstPath'] );
 482                 $cmd = $wgCustomConvertCommand;
 483                 $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
 484                 $cmd = str_replace( '%h', $params['physicalHeight'],
 485                         str_replace( '%w', $params['physicalWidth'], $cmd ) ); # Size
 486                 wfDebug( __METHOD__ . ": Running custom convert command $cmd\n" );
 487                 wfProfileIn( 'convert' );
 488                 $retval = 0;
 489                 $err = wfShellExecWithStderr( $cmd, $retval );
 490                 wfProfileOut( 'convert' );
 491
 492                 if ( $retval !== 0 ) {
 493                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 494
 495                         return $this->getMediaTransformError( $params, $err );
 496                 }
 497
 498                 return false; # No error
 499         }
 500
 501         /**
 502          * Get a MediaTransformError with error 'thumbnail_error'
 503          *
 504          * @param array $params Parameter array as passed to the transform* functions
 505          * @param string $errMsg Error message
 506          * @return MediaTransformError
 507          */
 508         public function getMediaTransformError( $params, $errMsg ) {
 509                 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 510                         $params['clientHeight'], $errMsg );
 511         }
 512
 513         /**
 514          * Transform an image using the built in GD library
 515          *
 516          * @param File $image File associated with this thumbnail
 517          * @param array $params Array with scaler params
 518          *
 519          * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
 520          */
 521         protected function transformGd( $image, $params ) {
 522                 # Use PHP's builtin GD library functions.
 523                 #
 524                 # First find out what kind of file this is, and select the correct
 525                 # input routine for this.
 526
 527                 $typemap = array(
 528                         'image/gif' => array( 'imagecreatefromgif', 'palette', 'imagegif' ),
 529                         'image/jpeg' => array( 'imagecreatefromjpeg', 'truecolor',
 530                                 array( __CLASS__, 'imageJpegWrapper' ) ),
 531                         'image/png' => array( 'imagecreatefrompng', 'bits', 'imagepng' ),
 532                         'image/vnd.wap.wbmp' => array( 'imagecreatefromwbmp', 'palette', 'imagewbmp' ),
 533                         'image/xbm' => array( 'imagecreatefromxbm', 'palette', 'imagexbm' ),
 534                 );
 535                 if ( !isset( $typemap[$params['mimeType']] ) ) {
 536                         $err = 'Image type not supported';
 537                         wfDebug( "$err\n" );
 538                         $errMsg = wfMessage( 'thumbnail_image-type' )->text();
 539
 540                         return $this->getMediaTransformError( $params, $errMsg );
 541                 }
 542                 list( $loader, $colorStyle, $saveType ) = $typemap[$params['mimeType']];
 543
 544                 if ( !function_exists( $loader ) ) {
 545                         $err = "Incomplete GD library configuration: missing function $loader";
 546                         wfDebug( "$err\n" );
 547                         $errMsg = wfMessage( 'thumbnail_gd-library', $loader )->text();
 548
 549                         return $this->getMediaTransformError( $params, $errMsg );
 550                 }
 551
 552                 if ( !file_exists( $params['srcPath'] ) ) {
 553                         $err = "File seems to be missing: {$params['srcPath']}";
 554                         wfDebug( "$err\n" );
 555                         $errMsg = wfMessage( 'thumbnail_image-missing', $params['srcPath'] )->text();
 556
 557                         return $this->getMediaTransformError( $params, $errMsg );
 558                 }
 559
 560                 $src_image = call_user_func( $loader, $params['srcPath'] );
 561
 562                 $rotation = function_exists( 'imagerotate' ) ? $this->getRotation( $image ) : 0;
 563                 list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 564                 $dst_image = imagecreatetruecolor( $width, $height );
 565
 566                 // Initialise the destination image to transparent instead of
 567                 // the default solid black, to support PNG and GIF transparency nicely
 568                 $background = imagecolorallocate( $dst_image, 0, 0, 0 );
 569                 imagecolortransparent( $dst_image, $background );
 570                 imagealphablending( $dst_image, false );
 571
 572                 if ( $colorStyle == 'palette' ) {
 573                         // Don't resample for paletted GIF images.
 574                         // It may just uglify them, and completely breaks transparency.
 575                         imagecopyresized( $dst_image, $src_image,
 576                                 0, 0, 0, 0,
 577                                 $width, $height,
 578                                 imagesx( $src_image ), imagesy( $src_image ) );
 579                 } else {
 580                         imagecopyresampled( $dst_image, $src_image,
 581                                 0, 0, 0, 0,
 582                                 $width, $height,
 583                                 imagesx( $src_image ), imagesy( $src_image ) );
 584                 }
 585
 586                 if ( $rotation % 360 != 0 && $rotation % 90 == 0 ) {
 587                         $rot_image = imagerotate( $dst_image, $rotation, 0 );
 588                         imagedestroy( $dst_image );
 589                         $dst_image = $rot_image;
 590                 }
 591
 592                 imagesavealpha( $dst_image, true );
 593
 594                 call_user_func( $saveType, $dst_image, $params['dstPath'] );
 595                 imagedestroy( $dst_image );
 596                 imagedestroy( $src_image );
 597
 598                 return false; # No error
 599         }
 600
 601         /**
 602          * Escape a string for ImageMagick's property input (e.g. -set -comment)
 603          * See InterpretImageProperties() in magick/property.c
 604          * @param string $s
 605          * @return string
 606          */
 607         function escapeMagickProperty( $s ) {
 608                 // Double the backslashes
 609                 $s = str_replace( '\\', '\\\\', $s );
 610                 // Double the percents
 611                 $s = str_replace( '%', '%%', $s );
 612                 // Escape initial - or @
 613                 if ( strlen( $s ) > 0 && ( $s[0] === '-' || $s[0] === '@' ) ) {
 614                         $s = '\\' . $s;
 615                 }
 616
 617                 return $s;
 618         }
 619
 620         /**
 621          * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
 622          * and GetPathComponent() in magick/utility.c.
 623          *
 624          * This won't work with an initial ~ or @, so input files should be prefixed
 625          * with the directory name.
 626          *
 627          * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
 628          * it's broken in a way that doesn't involve trying to convert every file
 629          * in a directory, so we're better off escaping and waiting for the bugfix
 630          * to filter down to users.
 631          *
 632          * @param string $path The file path
 633          * @param bool|string $scene The scene specification, or false if there is none
 634          * @throws MWException
 635          * @return string
 636          */
 637         function escapeMagickInput( $path, $scene = false ) {
 638                 # Die on initial metacharacters (caller should prepend path)
 639                 $firstChar = substr( $path, 0, 1 );
 640                 if ( $firstChar === '~' || $firstChar === '@' ) {
 641                         throw new MWException( __METHOD__ . ': cannot escape this path name' );
 642                 }
 643
 644                 # Escape glob chars
 645                 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
 646
 647                 return $this->escapeMagickPath( $path, $scene );
 648         }
 649
 650         /**
 651          * Escape a string for ImageMagick's output filename. See
 652          * InterpretImageFilename() in magick/image.c.
 653          * @param string $path The file path
 654          * @param bool|string $scene The scene specification, or false if there is none
 655          * @return string
 656          */
 657         function escapeMagickOutput( $path, $scene = false ) {
 658                 $path = str_replace( '%', '%%', $path );
 659
 660                 return $this->escapeMagickPath( $path, $scene );
 661         }
 662
 663         /**
 664          * Armour a string against ImageMagick's GetPathComponent(). This is a
 665          * helper function for escapeMagickInput() and escapeMagickOutput().
 666          *
 667          * @param string $path The file path
 668          * @param bool|string $scene The scene specification, or false if there is none
 669          * @throws MWException
 670          * @return string
 671          */
 672         protected function escapeMagickPath( $path, $scene = false ) {
 673                 # Die on format specifiers (other than drive letters). The regex is
 674                 # meant to match all the formats you get from "convert -list format"
 675                 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
 676                         if ( wfIsWindows() && is_dir( $m[0] ) ) {
 677                                 // OK, it's a drive letter
 678                                 // ImageMagick has a similar exception, see IsMagickConflict()
 679                         } else {
 680                                 throw new MWException( __METHOD__ . ': unexpected colon character in path name' );
 681                         }
 682                 }
 683
 684                 # If there are square brackets, add a do-nothing scene specification
 685                 # to force a literal interpretation
 686                 if ( $scene === false ) {
 687                         if ( strpos( $path, '[' ) !== false ) {
 688                                 $path .= '[0--1]';
 689                         }
 690                 } else {
 691                         $path .= "[$scene]";
 692                 }
 693
 694                 return $path;
 695         }
 696
 697         /**
 698          * Retrieve the version of the installed ImageMagick
 699          * You can use PHPs version_compare() to use this value
 700          * Value is cached for one hour.
 701          * @return string Representing the IM version.
 702          */
 703         protected function getMagickVersion() {
 704                 global $wgMemc;
 705
 706                 $cache = $wgMemc->get( "imagemagick-version" );
 707                 if ( !$cache ) {
 708                         global $wgImageMagickConvertCommand;
 709                         $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
 710                         wfDebug( __METHOD__ . ": Running convert -version\n" );
 711                         $retval = '';
 712                         $return = wfShellExec( $cmd, $retval );
 713                         $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
 714                         if ( $x != 1 ) {
 715                                 wfDebug( __METHOD__ . ": ImageMagick version check failed\n" );
 716
 717                                 return null;
 718                         }
 719                         $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
 720
 721                         return $matches[1];
 722                 }
 723
 724                 return $cache;
 725         }
 726
 727         static function imageJpegWrapper( $dst_image, $thumbPath ) {
 728                 imageinterlace( $dst_image );
 729                 imagejpeg( $dst_image, $thumbPath, 95 );
 730         }
 731
 732         /**
 733          * Returns whether the current scaler supports rotation (im and gd do)
 734          *
 735          * @return bool
 736          */
 737         public static function canRotate() {
 738                 $scaler = self::getScalerType( null, false );
 739                 switch ( $scaler ) {
 740                         case 'im':
 741                                 # ImageMagick supports autorotation
 742                                 return true;
 743                         case 'imext':
 744                                 # Imagick::rotateImage
 745                                 return true;
 746                         case 'gd':
 747                                 # GD's imagerotate function is used to rotate images, but not
 748                                 # all precompiled PHP versions have that function
 749                                 return function_exists( 'imagerotate' );
 750                         default:
 751                                 # Other scalers don't support rotation
 752                                 return false;
 753                 }
 754         }
 755
 756         /**
 757          * @param File $file
 758          * @param array $params Rotate parameters.
 759          *   'rotation' clockwise rotation in degrees, allowed are multiples of 90
 760          * @since 1.21
 761          * @return bool
 762          */
 763         public function rotate( $file, $params ) {
 764                 global $wgImageMagickConvertCommand;
 765
 766                 $rotation = ( $params['rotation'] + $this->getRotation( $file ) ) % 360;
 767                 $scene = false;
 768
 769                 $scaler = self::getScalerType( null, false );
 770                 switch ( $scaler ) {
 771                         case 'im':
 772                                 $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . " " .
 773                                         wfEscapeShellArg( $this->escapeMagickInput( $params['srcPath'], $scene ) ) .
 774                                         " -rotate -$rotation " .
 775                                         wfEscapeShellArg( $this->escapeMagickOutput( $params['dstPath'] ) );
 776                                 wfDebug( __METHOD__ . ": running ImageMagick: $cmd\n" );
 777                                 wfProfileIn( 'convert' );
 778                                 $retval = 0;
 779                                 // @todo FIXME: Undefined variable %env
 780                                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 781                                 wfProfileOut( 'convert' );
 782                                 if ( $retval !== 0 ) {
 783                                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 784
 785                                         return new MediaTransformError( 'thumbnail_error', 0, 0, $err );
 786                                 }
 787
 788                                 return false;
 789                         case 'imext':
 790                                 $im = new Imagick();
 791                                 $im->readImage( $params['srcPath'] );
 792                                 if ( !$im->rotateImage( new ImagickPixel( 'white' ), 360 - $rotation ) ) {
 793                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 794                                                 "Error rotating $rotation degrees" );
 795                                 }
 796                                 $result = $im->writeImage( $params['dstPath'] );
 797                                 if ( !$result ) {
 798                                         return new MediaTransformError( 'thumbnail_error', 0, 0,
 799                                                 "Unable to write image to {$params['dstPath']}" );
 800                                 }
 801
 802                                 return false;
 803                         default:
 804                                 return new MediaTransformError( 'thumbnail_error', 0, 0,
 805                                         "$scaler rotation not implemented" );
 806                 }
 807         }
 808
 809         /**
 810          * Rerurns whether the file needs to be rendered. Returns true if the
 811          * file requires rotation and we are able to rotate it.
 812          *
 813          * @param File $file
 814          * @return bool
 815          */
 816         public function mustRender( $file ) {
 817                 return self::canRotate() && $this->getRotation( $file ) != 0;
 818         }
 819 }