JPEG Noises beyond the First Compression Cycle
This work addresses a gap in digital forensics by analyzing previously overlooked JPEG noises, offering incremental improvements for detecting compression history.
The paper tackles the problem of JPEG noises beyond the first compression cycle, finding that noise distributions differ in higher cycles and depend on quantization parameters, with applications achieving state-of-the-art performance in uncovering JPEG compression history.
This paper focuses on the JPEG noises, which include the quantization noise and the rounding noise, during a JPEG compression cycle. The JPEG noises in the first compression cycle have been well studied; however, so far less attention has been paid on the JPEG noises in higher compression cycles. In this work, we present a statistical analysis on JPEG noises beyond the first compression cycle. To our knowledge, this is the first work on this topic. We find that the noise distributions in higher compression cycles are different from those in the first compression cycle, and they are dependent on the quantization parameters used between two successive cycles. To demonstrate the benefits from the statistical analysis, we provide two applications that can employ the derived noise distributions to uncover JPEG compression history with state-of-the-art performance.