[TYPO3-english] Typo3 6.1.7 table sys_file - wrong image size after fileupdate via FTP

[Marcus]

Hi everybody,

I got a projekt, where a lot of existing images (different image-height) 
were updated via FTP to the fileadmin-folder.
Now the image-sizes in the DB table sys_file keep the old image-height.

Is there a possibility to update/clear/renew the sys_file table?

Thanks in advance

Regards Marcus