Blind digital image forensics

a technology for detecting image authenticity and integrity without relying on any pre-embedded information

is emerging as a new hotspot in the digital media security filed. Since JPEG is the most popular image format and blocking artifacts are the inherent characteristics of JPEG images

using blocking artifacts more effectively for the authentication of JPEG image forgeries has very important practical significance and application value. First

the state-of-the-art algorithms of blind forensics based on JPEG image coding characteristics are classified and analyzed. Then we focus on blind forensic algorithms of tempered JPEG images based on blocking artifacts. Two types are introduced and summarized in detail: one based on blocking artifacts measurement and the other based on blocking artifacts grid extraction. Finally

we discuss unresolved problems and future research directions.