Accurate estimation of primary quantisation table with applications to tampering detection

There are many ways to accurately estimate the low-frequency region of the primary quantisation table in a double compressed JPEG image with different quality factors. However, they cannot accurately estimate the high-frequency region. An image compression model to describe the relationship between the primary compression and the second compression is used to present a simple approach to accurately estimate the whole primary quantisation table, and based on this, an efficient method for detection of image tampering involving JPEG recompression is proposed. The effectiveness of the proposed algorithms is tested by experiments and the experimental results are presented.