Pre-existing Corruption: The images might have been corrupt before recovery.
Overwritten Clusters: Parts of the JPEG file clusters could have been overwritten, causing irreversible corruption.
Same Drive Recovery: Saving recovered files to the same drive from which they were deleted might lead to corruption, or the drive could be infected by a virus.
Resolution
Save to a Different Drive: Always save recovered data to a different drive to avoid corruption issues.
Irrecoverable Files: Unfortunately, the files that were previously corrupted cannot be recovered.
