Use of footers can often truncate a photo, as many JPEGs contain thumbnails as an embedded object. Header-footer carving cannot be used to recover fragmented photos, and fragmented photos will appear to be partially recovered or corrupt if incorrect data is added. For example, JPEGs always begin with the hex sequence 'FFD8' and they must end with the hex sequence 'FFD9'. In Header-footer carving, a recovery program attempts to recover photos based on the standard starting and ending byte signature of the photo format. Header-footer carving, along with header-size carving, are by far the most common techniques for photo recovery. Simson Garfinkel showed that on average, 16% of JPEGs are fragmented, which means on average 16% of JPEGs are recovered partially or appear corrupt when recovered using techniques that cannot handle fragmented photos. Most of these techniques fail in the presence of file system fragmentation. There are many different file carving techniques that are used to recover photos. The majority of photo recovery programs work by using a technique called file carving (data carving). Logical Damage or the inability to view photos can occur for several reasons. 1 Recovering data after logical failure.

Picture rescue