A Brief Review on Existing Techniques for Detecting Digital Image Forgery

Law enforcement in the 21st century works on the evidence present in digital images or videos. Digital image processing is, thus, being heavily applied in the field of law enforcement, especially when it comes to detecting whether digital evidence related to legal matters has been tampered with or not. Due to the easy availability of various software, it is effortless for any law offender to have evidence such as digital images or videos transformed for their cause. Hence, two types of tampering detection techniques are used to maintain the integrity of digital evidence, namely Active and Passive. The active methods require that some kind of pre-embedded data be present in the image, using which detection can be performed while the passive techniques are applicable without any such condition. The differences, working, and classifications of these techniques are elaborately discussed here.