PhotoRec & TestDisk file recovery and FAT, FAT16, FAT32, NTFS undelete programs allow you recover accidentally deleted photos, videos or other files on SD cards and most other digital camera media and memory.
PhotoRec is file data recovery software designed to recover lost files including video, documents and archives from hard disks, CD-ROMs, and lost pictures (thus the Photo Recovery name) from digital camera memory. PhotoRec ignores the file system and goes after the underlying data, so it will still work even if your media's file system has been severely damaged or reformatted.
TestDisk is a powerful free data recovery program! It was primarily designed to recover lost partitions, repair FAT/NTFS boot sector, NTFS MFT and Ext2/Ext3 superblock and/or make non-booting disks bootable again when these symptoms are caused by faulty software or human error (such as accidentally deleting your Partition Table).