* No longer displaying ResolutionUnit at all
[lhc/web/wiklou.git] / includes / Exif.php
index d8c5a91..7e90175 100644 (file)
@@ -1,5 +1,5 @@
 <?php
-if (defined('MEDIAWIKI')) {
+if ( !defined( 'MEDIAWIKI' ) ) die();
 /**
  * @package MediaWiki
  * @subpackage Metadata
@@ -48,59 +48,71 @@ define('MW_EXIF_SRATIONAL', 10);    # Two SLONGs. The first SLONG is the numerator
 class Exif {
        /**#@+
         * @var array
+        * @access private
         */
-        
+       
        /**
         * Exif tags grouped by category, the tagname itself is the key and the type
         * is the value, in the case of more than one possible value type they are 
         * seperated by commas.
-        *
-        * @access private
         */
-       var $mExif;
-       
+       var $mExifTags;
+
        /**
         * A one dimentional array of all Exif tags
         */
-       var $mFlatExif;
-       
+       var $mFlatExifTags;
+
+       /**
+        * The raw Exif data returned by exif_read_data()
+        */
+       var $mRawExifData;
+
        /**
-        * A one dimentional array of all Exif tags that we'd want to save in
-        * the database or present on a page.
+        * A Filtered version of $mRawExifData that has been pruned of invalid
+        * tags and tags that contain content they shouldn't contain according
+        * to the Exif specification
         */
-       var $mValidExif;
+       var $mFilteredExifData;
 
+       /**
+        * Filtered and formatted Exif data, see FormatExif::getFormattedData()
+        */
+       var $mFormattedExifData;
+       
        /**#@-*/
 
        /**
         * Constructor
+        *
+        * @param string $file
         */
-       function Exif() {
+       function Exif( $file ) {
                /**
                 * Page numbers here refer to pages in the EXIF 2.2 standard
                 *
                 * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
                 */
-               $this->mExif = array(
+               $this->mExifTags = array(
                        # TIFF Rev. 6.0 Attribute Information (p22)
                        'tiff' => array(
                                # Tags relating to image structure
                                'structure' => array(
                                        'ImageWidth' => MW_EXIF_SHORT.','.MW_EXIF_LONG,         # Image width
                                        'ImageLength' => MW_EXIF_SHORT.','.MW_EXIF_LONG,        # Image height
-                                       'BitsPerSample' => MW_EXIF_SHORT,               # Number of bits per component
+                                       'BitsPerSample' => MW_EXIF_SHORT,                       # Number of bits per component
                                        # "When a primary image is JPEG compressed, this designation is not"
                                        # "necessary and is omitted." (p23)
-                                       'Compression' => MW_EXIF_SHORT,                 # Compression scheme #p23
-                                       'PhotometricInterpretation' => MW_EXIF_SHORT,   # Pixel composition #p23
-                                       'Orientation' => MW_EXIF_SHORT,                 # Orientation of image #p24
-                                       'SamplesPerPixel' => MW_EXIF_SHORT,             # Number of components
-                                       'PlanarConfiguration' => MW_EXIF_SHORT,         # Image data arrangement #p24
-                                       'YCbCrSubSampling' => MW_EXIF_SHORT,            # Subsampling ratio of Y to C #p24
-                                       'YCbCrPositioning' => MW_EXIF_SHORT,            # Y and C positioning #p24-25
-                                       'XResolution' => MW_EXIF_RATIONAL,              # Image resolution in width direction
-                                       'YResolution' => MW_EXIF_RATIONAL,              # Image resolution in height direction
-                                       'ResolutionUnit' => MW_EXIF_SHORT,              # Unit of X and Y resolution #(p26)
+                                       'Compression' => MW_EXIF_SHORT,                         # Compression scheme #p23
+                                       'PhotometricInterpretation' => MW_EXIF_SHORT,           # Pixel composition #p23
+                                       'Orientation' => MW_EXIF_SHORT,                         # Orientation of image #p24
+                                       'SamplesPerPixel' => MW_EXIF_SHORT,                     # Number of components
+                                       'PlanarConfiguration' => MW_EXIF_SHORT,                 # Image data arrangement #p24
+                                       'YCbCrSubSampling' => MW_EXIF_SHORT,                    # Subsampling ratio of Y to C #p24
+                                       'YCbCrPositioning' => MW_EXIF_SHORT,                    # Y and C positioning #p24-25
+                                       'XResolution' => MW_EXIF_RATIONAL,                      # Image resolution in width direction
+                                       'YResolution' => MW_EXIF_RATIONAL,                      # Image resolution in height direction
+                                       'ResolutionUnit' => MW_EXIF_SHORT,                      # Unit of X and Y resolution #(p26)
                                ),
                                
                                # Tags relating to recording offset
@@ -152,8 +164,8 @@ class Exif {
                                'configuration' => array(
                                        'ComponentsConfiguration' => MW_EXIF_UNDEFINED,         # Meaning of each component #p33
                                        'CompressedBitsPerPixel' => MW_EXIF_RATIONAL,           # Image compression mode
-                                       'PixelYDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,            # Valid image width
-                                       'PixelXDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,            # Valind image height
+                                       'PixelYDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,    # Valid image width
+                                       'PixelXDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,    # Valind image height
                                ),
                                
                                # Tags relating to related user information
@@ -199,7 +211,7 @@ class Exif {
                                        'SpatialFrequencyResponse' => MW_EXIF_UNDEFINED,        # Spatial frequency response
                                        'FocalPlaneXResolution' => MW_EXIF_RATIONAL,            # Focal plane X resolution
                                        'FocalPlaneYResolution' => MW_EXIF_RATIONAL,            # Focal plane Y resolution
-                                       'FocalPlaneResolutionUnit' => MW_EXIF_SHORT,            # Focal plane resolution unit
+                                       'FocalPlaneResolutionUnit' => MW_EXIF_SHORT,            # Focal plane resolution unit #p46
                                        'SubjectLocation' => MW_EXIF_SHORT,                     # Subject location
                                        'ExposureIndex' => MW_EXIF_RATIONAL,                    # Exposure index
                                        'SensingMethod' => MW_EXIF_SHORT,                       # Sensing method #p46
@@ -262,373 +274,716 @@ class Exif {
                );
 
                $this->makeFlatExifTags();
-               $this->makeValidExifTags();
+               wfSuppressWarnings();
+               $this->mRawExifData = exif_read_data( $file );
+               wfRestoreWarnings();
+               $this->makeFilteredData();
+               $this->makeFormattedData();
        }
-
-       /**
-        * Get the raw list of exiftags
-        *
+       
+       /**#@+
         * @access private
-        * @return array
-       */
-       function getExif() {
-               return $this->mExif;
-       }
-
+        */
        /**
         * Generate a flat list of the exif tags
         */
        function makeFlatExifTags() {
-               $exif = $this->getExif();
-               $this->extractTags( $exif );
+               $this->extractTags( $this->mExifTags );
        }
        
        /**
         * A recursing extractor function used by makeFlatExifTags()
+        *
+        * Note: This used to use an array_walk function, but it made PHP5
+        * segfault, see `cvs diff -u -r 1.4 -r 1.5 Exif.php`
         */
-       function extractTags( $tagset ) {
+       function extractTags( &$tagset ) {
                foreach( $tagset as $key => $val ) {
                        if( is_array( $val ) ) {
                                $this->extractTags( $val );
                        } else {
-                               $this->mFlatExif[$key] = $val;
+                               $this->mFlatExifTags[$key] = $val;
                        }
                }
        }
        
        /**
-        * Produce a list of all Exif tags appropriate for user output
-        *
-        * Produce a list of all tags that we want to show in output, in order not to 
-        * output binary gibberish such as raw thumbnails we strip all tags
-        * with the datatype of UNDEFINED.
-        *
-        * @todo We might actually want to display some of the UNDEFINED
-        *       stuff, but we strip it for now.
+        * Make $this->mFilteredExifData
         */
-       function makeValidExifTags() {
-               foreach( $this->mFlatExif as $key => $val ) {
-                       if( strpos( $val, (string)MW_EXIF_UNDEFINED ) !== false ) {
-                               continue;
+       function makeFilteredData() {
+               $this->mFilteredExifData = $this->mRawExifData;
+               
+               foreach( $this->mFilteredExifData as $k => $v ) {
+                       if ( !in_array( $k, array_keys( $this->mFlatExifTags ) ) ) {
+                               $this->debug( $v, __FUNCTION__, "'$k' is not a valid Exif tag" );
+                               unset( $this->mFilteredExifData[$k] );
                        }
-                       $this->mValidExif[] = $key;
                }
+
+               foreach( $this->mFilteredExifData as $k => $v ) {
+                       if ( !$this->validate($k, $v) ) {
+                               $this->debug( $v, __FUNCTION__, "'$k' contained invalid data" );
+                               unset( $this->mFilteredExifData[$k] );
+                       }
+               }
+       }
+
+       function makeFormattedData( $data = null ) {
+               $format = new FormatExif( $this->getFilteredData() );
+               $this->mFormattedExifData = $format->getFormattedData();
+       }
+       /**#@-*/
+
+       /**#@+
+        * @return array
+        */
+       /**
+        * Get $this->mRawExifData
+        */
+       function getData() {
+               return $this->mRawExifData;
+       }
+
+       /**
+        * Get $this->mFilteredExifData
+        */
+       function getFilteredData() {
+               return $this->mFilteredExifData;
        }
 
-        /**
-         * The version of the output format
-         *
-         * Before the actual metadata information is saved in the database we
-         * strip some of it since we don't want to save things like thumbnails
-         * which usually accompany Exif data. This value gets saved in the
-         * database along with the actual Exif data, and if the version in the
-         * database doesn't equal the value returned by this function the Exif
-         * data is regenerated.
-         *
-         * @return int
-         */
+       /**
+        * Get $this->mFormattedExifData
+        */
+       function getFormattedData() {
+               return $this->mFormattedExifData;
+       }
+       /**#@-*/
+       
+       /**
+        * The version of the output format
+        *
+        * Before the actual metadata information is saved in the database we
+        * strip some of it since we don't want to save things like thumbnails
+        * which usually accompany Exif data. This value gets saved in the
+        * database along with the actual Exif data, and if the version in the
+        * database doesn't equal the value returned by this function the Exif
+        * data is regenerated.
+        *
+        * @return int
+        */
        function version() {
                return 1; // We don't need no bloddy constants!
        }
 
        /**#@+
         * Validates if a tag value is of the type it should be according to the Exif spec
-        * 
+        *
+        * @access private
+        *
         * @param mixed $in The input value to check
         * @return bool
         */
        function isByte( $in ) {
-               return is_numeric( $in ) && $in >= 0 && $in <= 255;
+               if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 255 ) {
+                       $this->debug( $in, __FUNCTION__, true );
+                       return true;
+               } else {
+                       $this->debug( $in, __FUNCTION__, false );
+                       return false;
+               }
        }
        
        function isASCII( $in ) {
-               return true; // TODO: FIXME
+               if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
+                       $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
+                       return false;
+               }
+               
+               if ( preg_match( "/^\s*$/", $in ) ) {
+                       $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
+                       return false;
+               }
+               
+               if ( strlen($in) > 1024 ) { // TODO: This might not be according to the spec
+                       $this->debug( $in, __FUNCTION__, 'input was too long' );
+                       return false;
+               }
+               
+               return true;
        }
 
        function isShort( $in ) {
-               return is_numeric( $in ) && $in >= 0 && $in <= 65536;
+               if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 65536 ) {
+                       $this->debug( $in, __FUNCTION__, true );
+                       return true;
+               } else {
+                       $this->debug( $in, __FUNCTION__, false );
+                       return false;
+               }
        }
 
        function isLong( $in ) {
-               return is_numeric( $in ) && $in >= 0 && $in <= 4294967296;
-
+               if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 4294967296 ) {
+                       $this->debug( $in, __FUNCTION__, true );
+                       return true;
+               } else {
+                       $this->debug( $in, __FUNCTION__, false );
+                       return false;
+               }
        }
        
        function isRational( $in ) {
-               $in = explode( '/', $in, 2 );
-               return $this->isLong( $in[0] ) && $this->isLong( $in[1] );
+               if ( @preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
+                       return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
+               } else {
+                       $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
+                       return false;
+               }
        }
 
        function isUndefined( $in ) {
-               return true;
+               if ( preg_match( "/^\d{4}$/", $in ) ) { // Allow ExifVersion and FlashpixVersion
+                       $this->debug( $in, __FUNCTION__, true );
+                       return true;
+               } else {
+                       $this->debug( $in, __FUNCTION__, false );
+                       return false;
+               }
        }
 
        function isSlong( $in ) {
-               return $this->isLong( abs( $in ) );
+               if ( $this->isLong( abs( $in ) ) ) {
+                       $this->debug( $in, __FUNCTION__, true );
+                       return true;
+               } else {
+                       $this->debug( $in, __FUNCTION__, false );
+                       return false;
+               }
        }
 
        function isSrational( $in ) {
-               $in = explode( '/', $in, 2 );
-               return $this->isSlong( $in[0] ) && $this->isSlong( $in[1] );
+               if ( preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
+                       return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
+               } else {
+                       $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
+                       return false;
+               }
        }
        /**#@-*/
 
        /**
-        * Validates if a tag has a legal value according to the Exif spec, presumes
-        * that the given tag is valid ( has been checked in advance with
-        * $this->mValidExif )
+        * Validates if a tag has a legal value according to the Exif spec
+        *
+        * @access private
         *
         * @param string $tag The tag to check
         * @param mixed  $val The value of the tag
         * @return bool
         */
        function validate( $tag, $val ) {
+               $debug = "tag is '$tag'";
                // Fucks up if not typecast 
-               switch( (string)$this->mFlatExif[$tag] ) {
+               switch( (string)$this->mFlatExifTags[$tag] ) {
                        case (string)MW_EXIF_BYTE:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isByte( $val );
                        case (string)MW_EXIF_ASCII:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isASCII( $val );
                        case (string)MW_EXIF_SHORT:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isShort( $val );
                        case (string)MW_EXIF_LONG:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isLong( $val );
                        case (string)MW_EXIF_RATIONAL:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isRational( $val );
                        case (string)MW_EXIF_UNDEFINED:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isUndefined( $val );
                        case (string)MW_EXIF_SLONG:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isSlong( $val );
                        case (string)MW_EXIF_SRATIONAL:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isSrational( $val );
                        case (string)MW_EXIF_SHORT.','.MW_EXIF_LONG:
+                               $this->debug( $val, __FUNCTION__, $debug );
                                return $this->isShort( $val ) || $this->isLong( $val );
                        default:
-                               wfDebug( "Exif: The tag \"$tag\" had an invalid value: \"$val\"\n" );
+                               $this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" );
                                return false;
                }
        }
 
+       /**
+        * Conviniance function for debugging output
+        *
+        * @access private
+        *
+        * @param mixed $in 
+        * @param string $fname
+        * @param mixed $action
+        */
+        function debug( $in, $fname, $action = null ) {
+               $type = gettype( $in );
+               $class = ucfirst( __CLASS__ );
+               if ( $type === 'array' )
+                       $in = print_r( $in, true ); 
+        
+               if ( $action === true )
+                       wfDebug( "$class::$fname: accepted: '$in' (type: $type)\n");
+               elseif ( $action === false ) 
+                       wfDebug( "$class::$fname: rejected: '$in' (type: $type)\n");
+               elseif ( $action === null )
+                       wfDebug( "$class::$fname: input was: '$in' (type: $type)\n");
+               else
+                       wfDebug( "$class::$fname: $action (type: $type; content: '$in')\n");
+       }
+
+}
+
+/**
+ * @package MediaWiki
+ * @subpackage Metadata
+ */
+class FormatExif {
+       /**
+        * The Exif data to format
+        *
+        * @var array
+        * @access private
+        */
+       var $mExif;
+       
+       /**
+        * Constructor
+        *
+        * @param array $exif The Exif data to format ( as returned by
+        *                    Exif::getFilteredData() )
+        */
+       function FormatExif( $exif ) {
+               $this->mExif = $exif;
+       }
+       
        /**
         * Numbers given by Exif user agents are often magical, that is they
         * should be replaced by a detailed explanation depending on their
         * value which most of the time are plain integers. This function
         * formats Exif values into human readable form.
         *
-        * @param string $tag The tag to be formatted
-        * @param mixed  $val The value of the tag
-        * @return string
+        * @return array
         */
-       function format( $tag, $val ) {
+       function getFormattedData() {
                global $wgLang;
                
-               switch( $tag ) {
-               case 'Compression':
-                       switch( $val ) {
-                       case 1: case 6:
-                               return $this->msg( $tag, $val );
-                       }
-               
-               case 'PhotometricInterpretation':
-                       switch( $val ) {
-                       case 2: case 6:
-                               return $this->msg( $tag, $val );
-                       }
-               
-               case 'Orientation':
-                       switch( $val ) {
-                       case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
-                               return $this->msg( $tag, $val );
-                       }
-               
-               // TODO: If this field does not exist use 1
-               case 'PlanarConfiguration':
-                       switch( $val ) {
-                       case 1: case 2:
-                               return $this->msg( $tag, $val );
-                       }
-               
-               // TODO: YCbCrSubSampling
-               // TODO: YCbCrPositioning
-               // TODO: If this field does not exists use 2
-               case 'ResolutionUnit': #p26
-                       switch( $val ) {
-                       case 2: case 3:
-                               return $this->msg( $tag, $val );
-                       }
-               
-               // TODO: YCbCrCoefficients  #p27 (see annex E)
-               case 'ExifVersion': case 'FlashpixVersion':
-                       return "$val"/100;
-               
-               case 'ColorSpace':
-                       switch( $val ) {
-                       case 1: case 'FFFF.H':
-                               return $this->msg( $tag, $val );
-                       }
-               
-               case 'ComponentsConfiguration':
-                       switch( $val ) {
-                       case 0: case 1: case 2: case 3: case 4: case 5: case 6:
-                               return $this->msg( $tag, $val );
-                       }
-               
-               case 'DateTime':
-               case 'DateTimeOriginal':
-               case 'DateTimeDigitized':
-                       return $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
+               $tags =& $this->mExif;
+
+               $resolutionunit = !isset( $tags['ResolutionUnit'] ) || $tags['ResolutionUnit'] == 2 ? 2 : 3;
+               unset( $tags['ResolutionUnit'] );
                
-               case 'ExposureProgram':
-                       switch( $val ) {
-                       case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'MeteringMode':
-                       switch( $val ) {
-                       case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'LightSource':
-                       switch( $val ) {
-                       case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
-                       case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
-                       case 21: case 22: case 23: case 24: case 255:
-                               return $this->msg( $tag, $val );
-                       }
-               // TODO: Flash
-               case 'SensingMethod':
-                       switch( $val ) {
-                       case 1: case 2: case 3: case 4: case 5: case 7: case 8:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'FileSource':
-                       switch( $val ) {
-                       case 3:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'SceneType':
-                       switch( $val ) {
-                       case 1:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'CustomRendered':
-                       switch( $val ) {
-                       case 0: case 1:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'ExposureMode':
-                       switch( $val ) {
-                       case 0: case 1: case 2:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'WhiteBalance':
-                       switch( $val ) {
-                       case 0: case 1:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'SceneCaptureType':
-                       switch( $val ) {
-                       case 0: case 1: case 2: case 3:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GainControl':
-                       switch( $val ) {
-                       case 0: case 1: case 2: case 3: case 4:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'Contrast':
-                       switch( $val ) {
-                       case 0: case 1: case 2:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'Saturation':
-                       switch( $val ) {
-                       case 0: case 1: case 2:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'Sharpness':
-                       switch( $val ) {
-                       case 0: case 1: case 2:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'SubjectDistanceRange':
-                       switch( $val ) {
-                       case 0: case 1: case 2: case 3:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSLatitudeRef':
-                       switch( $val ) {
-                       case 'N': case 'S':
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSLongitudeRef':
-                       switch( $val ) {
-                       case 'E': case 'W':
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSStatus':
-                       switch( $val ) {
-                       case 'A': case 'V':
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSMeasureMode':
-                       switch( $val ) {
-                       case 2: case 3:
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSSpeedRef':
-                       switch( $val ) {
-                       case 'K': case 'M': case 'N':
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSTrackRef':
-                       switch( $val ) {
-                       case 'T': case 'M':
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSImgDirectionRef':
-                       switch( $val ) {
-                       case 'T': case 'M':
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSDestLatitudeRef':
-                       switch( $val ) {
-                       case 'N': case 'S':
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSDestLongitudeRef':
-                       switch( $val ) {
-                       case 'E': case 'W':
-                               return $this->msg( $tag, $val );
-                       }
-               case 'GPSDestBearingRef':
-                       switch( $val ) {
-                       case 'T': case 'M':
-                               return $this->msg( $tag, $val );                                        
-                       }
-               case 'GPSDateStamp':
-                       return $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
+               foreach( $tags as $tag => $val ) {
+                       switch( $tag ) {
+                       case 'Compression':
+                               switch( $val ) {
+                               case 1: case 6:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'PhotometricInterpretation':
+                               switch( $val ) {
+                               case 2: case 6:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                       
+                       case 'Orientation':
+                               switch( $val ) {
+                               case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                       
+                       case 'PlanarConfiguration':
+                               switch( $val ) {
+                               case 1: case 2:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                       
+                       // TODO: YCbCrSubSampling
+                       // TODO: YCbCrPositioning
+                       
+                       case 'XResolution':
+                       case 'YResolution':
+                               switch( $resolutionunit ) {
+                                       case 2:
+                                               $tags[$tag] = $this->msg( 'XYResolution', 'i', $this->formatNum( $val ) );
+                                               break;
+                                       case 3:
+                                               $this->msg( 'XYResolution', 'c', $this->formatNum( $val ) );
+                                               break;
+                                       default:
+                                               $tags[$tag] = $val;
+                                               break;
+                               }
+                               break;
+                               
+                       // TODO: YCbCrCoefficients  #p27 (see annex E)
+                       case 'ExifVersion': case 'FlashpixVersion':
+                               $tags[$tag] = "$val"/100;
+                               break;
+                       
+                       case 'ColorSpace':
+                               switch( $val ) {
+                               case 1: case 'FFFF.H':
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                       
+                       case 'ComponentsConfiguration':
+                               switch( $val ) {
+                               case 0: case 1: case 2: case 3: case 4: case 5: case 6:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                       
+                       case 'DateTime':
+                       case 'DateTimeOriginal':
+                       case 'DateTimeDigitized':
+                               $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
+                               break;
+                       
+                       case 'ExposureProgram':
+                               switch( $val ) {
+                               case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
 
-               // This is not in the Exif standard, just a special
-               // case for our purposes which enables wikis to wikify
-               // the make and model to write articles about them.
-               case 'Make': case 'Model':
-                       return wfMsg( strtolower( "exif-$tag-value" ), $val );
-               default:
-                       return $val;
+                       case 'SubjectDistance':
+                               $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
+                               break;
+       
+                       case 'MeteringMode':
+                               switch( $val ) {
+                               case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'LightSource':
+                               switch( $val ) {
+                               case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
+                               case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
+                               case 21: case 22: case 23: case 24: case 255:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       // TODO: Flash
+                       case 'FocalPlaneResolutionUnit':
+                               switch( $val ) {
+                               case 2:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                                               
+                       case 'SensingMethod':
+                               switch( $val ) {
+                               case 1: case 2: case 3: case 4: case 5: case 7: case 8:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'FileSource':
+                               switch( $val ) {
+                               case 3:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'SceneType':
+                               switch( $val ) {
+                               case 1:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'CustomRendered':
+                               switch( $val ) {
+                               case 0: case 1:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'ExposureMode':
+                               switch( $val ) {
+                               case 0: case 1: case 2:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'WhiteBalance':
+                               switch( $val ) {
+                               case 0: case 1:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'SceneCaptureType':
+                               switch( $val ) {
+                               case 0: case 1: case 2: case 3:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+       
+                       case 'GainControl':
+                               switch( $val ) {
+                               case 0: case 1: case 2: case 3: case 4:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'Contrast':
+                               switch( $val ) {
+                               case 0: case 1: case 2:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'Saturation':
+                               switch( $val ) {
+                               case 0: case 1: case 2:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'Sharpness':
+                               switch( $val ) {
+                               case 0: case 1: case 2:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'SubjectDistanceRange':
+                               switch( $val ) {
+                               case 0: case 1: case 2: case 3:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'GPSLatitudeRef':
+                       case 'GPSDestLatitudeRef':
+                               switch( $val ) {
+                               case 'N': case 'S':
+                                       $tags[$tag] = $this->msg( 'GPSLatitude', $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'GPSLongitudeRef':
+                       case 'GPSDestLongitudeRef':
+                               switch( $val ) {
+                               case 'E': case 'W':
+                                       $tags[$tag] = $this->msg( 'GPSLongitude', $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'GPSStatus':
+                               switch( $val ) {
+                               case 'A': case 'V':
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'GPSMeasureMode':
+                               switch( $val ) {
+                               case 2: case 3:
+                                       $tags[$tag] = $this->msg( $tag, $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'GPSSpeedRef':
+                       case 'GPSDestDistanceRef':
+                               switch( $val ) {
+                               case 'K': case 'M': case 'N':
+                                       $tags[$tag] = $this->msg( 'GPSSpeed', $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'GPSTrackRef':
+                       case 'GPSImgDirectionRef':
+                       case 'GPSDestBearingRef':
+                               switch( $val ) {
+                               case 'T': case 'M':
+                                       $tags[$tag] = $this->msg( 'GPSDirection', $val );
+                                       break;
+                               default:
+                                       $tags[$tag] = $val;
+                                       break;
+                               }
+                               break;
+                               
+                       case 'GPSDateStamp':
+                               $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
+                               break;
+       
+                       // This is not in the Exif standard, just a special
+                       // case for our purposes which enables wikis to wikify
+                       // the make, model and software name to link to their articles.
+                       case 'Make':
+                       case 'Model':
+                       case 'Software':
+                               $tags[$tag] = $this->msg( $tag, '', $val );
+                               break;
+                       default:
+                               $tags[$tag] = $this->formatNum( $val );
+                               break;
+                       }
                }
+
+               return $tags;
        }
 
        /**
-        * Conviniance function for format()
+        * Conviniance function for getFormattedData()
+        *
+        * @access private
         *
         * @param string $tag The tag name to pass on
         * @param string $val The value of the tag
+        * @param string $arg An argument to pass ($1)
         * @return string A wfMsg of "exif-$tag-$val" in lower case
         */
-       function msg( $tag, $val ) {
-               return wfMsg( strtolower("exif-$tag-$val") );
+       function msg( $tag, $val, $arg = null ) {
+               if ($val === '')
+                       $val = 'value';
+               return wfMsg( strtolower( "exif-$tag-$val" ), $arg );
        }
-}
 
-} // MEDIAWIKI
+       /**
+        * Format a number, convert numbers from fractions into floating point
+        * numbers
+        *
+        * @access private
+        *
+        * @param mixed $num The value to format
+        * @return mixed A floating point number or whatever we were fed
+        */
+       function formatNum( $num ) {
+               if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
+                       return $m[2] != 0 ? $m[1] / $m[2] : $num;
+               else
+                       return $num;
+       }
+}