Blind Authentication Using Periodic Properties of Interpolation

Abstract

Abstract-In this paper we analyze and analytically describe the specific statistical changes brought into the covariance structure of signal by the interpolation process. We show that interpolated signals and their derivatives contain specific detectable periodic properties. Based on this, we propose a blind, efficient and automatic method capable of finding traces of resampling and interpolation. The proposed method can be very useful in many areas, especially in image security and authentication. For instance, when two or more images are spliced together, to create high quality and consistent image forgeries, almost always geometric transformations such as scaling, rotation or skewing are needed. These procedures are typically based on a resampling and interpolation step. By having a method capable of detecting the traces of resampling, we can significantly reduce the successful usage of such forgeries. Among other points, the presented method is also very useful in estimation of the geometric transformations factors.

Detecting Trace of Seam Carving for Forensic Analysis

“…The detector determined if the images had undergone resizing and the rate of interpolation. Mahdian and Saic analytically extended Gallaher's method [5]. They proved that the variance of the n-th order derivative of an interpolated signal has a periodicity equal to the sampling rate of the original signal if the given signal satisfies the stationary signal requirements.…”

Splicing Forgery Exposure in Digital Image by Detecting Noise Discrepancies

“…Thus these traces can be detected. Similar approach was also proposed in [2]. The weakness of these methods is that they only show good performance to images in TIFF format and are not robust to JPEG compression.…”

Analysis Method of Digital Forgeries on the Filtered Tampered Images

“…An important task of the tampered image is to detect an interpolation factor and regions. Therefore, key issues for forgery detectors are to solve the problems of interpolation technologies between tampered pixels for determining the interpolation factor and the tampered regions [1]- [5]. The detectors should allow us to estimate the accurate interpolation factor and the robust interpolated region from the forged image.…”

“…Mahdian and S. Saic [5] described that specific periodic properties presented in the covariance structure of interpolated signals and their derivatives. This method is used for the larger window size (128x128) in determining the interpolated portions.…”