Missing JPEG images on SD card

[terry_g]

When you delete a file or picture from a card or a hard drive the file or picture is not deleted.
There is a Master File Table on the card or something like that I can't remember the correct name.
The master file table is an index with the filename and location on the file on the storage device.
When the file or picture is deleted it is only deleted from the index.
Recovery software locates the missing file and puts it back in the index.

If a file transfer from a camera or card reader is interrupted during transfer it can cause
the file and/or index to become corrupted. Disconnecting a USB cable or a program crash come to mind.

Terry