PhotoRec – More Than Image Recovery
PhotoRec is a free data recovery software that complements TestDisk. TestDisk can recover partitions and deleted files by checking and repairing partition tables and file system data, while PhotoRec ignores file system and scans the disk for known files. PhotoRec is ideal to recover images from any media. Compact Flash cards and other removable media often store valuable digital images. In case the data gets corrupted it is still possible to recover image files regardless of the state of file system. Even from formatted memory cards PhotoRec is able to recover files if the data was not overwritten.
Because of the way how file systems save and delete files it is possible to recover them in most cases of unintentional deletion or data corruption. The easiest way is to recover deleted files because the files are not removed from the disk, they are only marked as deleted. This principle is used by TestDisk. It searches for deleted files, lists them and you select which ones should be undeleted. However, this process depends on the data from file system tables. If the file system is corrupted, formatted or otherwise damaged it is not possible to get information about saved files. But the file data is still present on the disk. So if you can recognize this data you can at least theoretically recover the file. This principle is using PhotoRec.
PhotoRec reads raw disk data and scans for file header which contains known signatures. A signature is a sequence of bytes typical for one type of files. When a file header is found it is possible to extract additional data that belongs to the file. This principle can be used in most cases because almost all file systems store files in a way that allows recovery. One exception is ReiserFS which uses optimizations that prevent search for file signatures.
PhotoRec is a command line program available for all popular operating systems. It supports hard drives, removable media (USB Flash disks, CompactFlash cards, SD cards, MMC, etc.), portable media players like iPod and digital cameras (confirmed digital image recovery from Canon EOS300D,10D; Casio Exilim EX-Z 750; HP PhotoSmart 620, 850, 935; Nikon CoolPix 775, 950, 5700; Olympus C350N, C860L; Mju 400 Digital, Stylus 300; Sony Alpha DSLR, DSC-P9; Pentax K20D; Praktica DCZ-3.4). Practically, you can use PhotoRec on typical Windows system as digital image recovery software. For successful photo and image recovery from formatted digital photo memory card you only need card reader and PhotoRec.
PhotoRec supports more than 200 file types including popular image formats. The only things it can not recover are the file names. This data is stored in the file system structure which PhotoRec is not using. In some cases the name of the image is stored in the file, in other cases PhotoRec will assign automatically created names to recovered files and you are then able to rename them.
Working with PhotoRec is simple. It requires no installation. After you run the software you select the disk and partition, define options and choose which file types should PhotoRec look for. Check only those file types that you expect to recover. This will reduce the time needed to scan the disk. Finally you define the location where the recovered files should be stored and PhotoRec is ready to start the recovery process.
PhotoRec is a simple but powerful data recovery software which can be used in cases where TestDisk can not recover files because of corrupted file system or formatted disk. Both TestDisk and PhotoRec are free, open source and available for all popular operating systems. You get not only cheap and elegant solution to recover lost or deleted files, you also get professional solution for digital photo recovery from formatted disks and memory cards.
- Free and open source
- No installation required
- Supports recovery of most popular file types
- Runs under most operating systems
- Text based command line utility