Categories: Symbian C++ | Technical Solution | S60 3rd Edition | Imaging | Code Examples

This page was last modified 11:15, 30 April 2008.

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Description

EXIF version information in image metadata is stored as a 4-byte (32-bit integer) ASCII string, which is not NULL-terminated. The following solution shows how to extract this information using CExifRead and convert it to a unicode descriptor for displaying purposes.

Solution

 #define KEXIFVersionInfoLength 4
 
 #include <exifread.h>     // for CExifRead (ExifLib.lib)
 #include <utf.h>          // for CnvUtfConverter (charconv.lib)

 // imageData is a buffer containing the image data
 CExifRead* exifRead = CExifRead::NewL( imageData );
 CleanupStack::PushL(exifRead);
 
 TUint32 exifVersion = 0;
 TBuf8<KEXIFVersionInfoLength> exifVerDes8;
 TBuf<KEXIFVersionInfoLength> exifVerDes;
 TInt err = exifRead->GetExifVersion( exifVersion );
 
 CleanupStack::PopAndDestroy(2); // exifRead, imageData
   
 if(err == KErrNone)
   {
   // Copy to a temporary UTF-8 string and convert to unicode descriptor
   exifVerDes8.Copy( (TUint8*)&exifVersion, KEXIFVersionInfoLength );  
   CnvUtfConverter::ConvertToUnicodeFromUtf8( exifVerDes, exifVerDes8 );
   }
 else
   {
   // Error handling
   }