Publication Details
Title: Spectral Methods to Determine the Exact Scaling Factor of Resample Digital Images
Author: S. Pfennig and M. Kirchner
Group: Vision
Date: May 2012
PDF: http://www.icsi.berkeley.edu/pubs/vision/ICSI_spectralmethods.pdf
Overview:
This paper combines analytical models of periodic interpolation artifacts with recent empirical findings on the spectral energy distribution of rescaled images to infer exact transformation parameters in a passive-blind forensic setting. We present a measure to solve a long-known ambiguity between upscaling and downscaling in the forensic analysis of resampled signals and thus substantially limit the range of candidate scaling factors. The effectiveness of our method is backed with empirical evidence on a large set of images and scaling factors.
Acknowledgements:
This work was partially funded by the Deutscher Akademischer Austausch Dienst (DAAD) through a postdoctoral fellowship.
Bibliographic Information:
Invited paper, "Image Forensics Techniques" special session, proceedings of the 5th International Symposium on Communications, Control, and Signal Processing (ISCCSP), Rome, Italy
Bibliographic Reference:
S. Pfennig and M. Kirchner. Spectral Methods to Determine the Exact Scaling Factor of Resample Digital Images. Invited paper, "Image Forensics Techniques" special session, proceedings of the 5th International Symposium on Communications, Control, and Signal Processing (ISCCSP), Rome, Italy, May 2012
Author: S. Pfennig and M. Kirchner
Group: Vision
Date: May 2012
PDF: http://www.icsi.berkeley.edu/pubs/vision/ICSI_spectralmethods.pdf
Overview:
This paper combines analytical models of periodic interpolation artifacts with recent empirical findings on the spectral energy distribution of rescaled images to infer exact transformation parameters in a passive-blind forensic setting. We present a measure to solve a long-known ambiguity between upscaling and downscaling in the forensic analysis of resampled signals and thus substantially limit the range of candidate scaling factors. The effectiveness of our method is backed with empirical evidence on a large set of images and scaling factors.
Acknowledgements:
This work was partially funded by the Deutscher Akademischer Austausch Dienst (DAAD) through a postdoctoral fellowship.
Bibliographic Information:
Invited paper, "Image Forensics Techniques" special session, proceedings of the 5th International Symposium on Communications, Control, and Signal Processing (ISCCSP), Rome, Italy
Bibliographic Reference:
S. Pfennig and M. Kirchner. Spectral Methods to Determine the Exact Scaling Factor of Resample Digital Images. Invited paper, "Image Forensics Techniques" special session, proceedings of the 5th International Symposium on Communications, Control, and Signal Processing (ISCCSP), Rome, Italy, May 2012