IMAGE FORGERY DETECTION Justin Siao IMAGE FORGERY DETECTION

PIXEL BASED FORMAT BASED CAMERA BASED PHYSICS BASED GEOMETRIC BASED OUTLINE

PIXEL BASED METHODS: CLONING Discrete Cosine Transform Principle Component Analysis PIXEL BASED METHODS: CLONING

PIXEL BASED METHODS: OTHER Resampling Scaling Expectation/Maximization Algorithm Splicing Disrupts higher-order Fourier statistics Statistical PIXEL BASED METHODS: OTHER

FORMAT BASED METHODS JPEG Quantization Double JPEG JPEG Blocking Quantization techniques vary by model Double JPEG Editing and saving to JPEG causes double compression JPEG Blocking JPEGs compress by 8x8 pixel blocks Manipulation will disturb these blocks FORMAT BASED METHODS

CAMERA BASED METHODS: CHROMATIC ABERRATION Image have a specific field of misalignment of color channels Any part of the image which mismatches the field indicates manipulation CAMERA BASED METHODS: CHROMATIC ABERRATION

CAMERA BASED METHODS: OTHER Color Filter Array Uses interpolation. Pixels must correspond Camera Response Cameras enhance light non-linearly Sensor Noise Compares expected noise with extracted noise CAMERA BASED METHODS: OTHER

PHYSICS BASED METHODS: LIGHT DIRECTION & ENVIRONMENT Light source can be plotted by angle of luminescence. Light on object must match environmental lighting PHYSICS BASED METHODS: LIGHT DIRECTION & ENVIRONMENT

GEOMETRIC BASED METHODS: PRINCIPLE POINT & METRIC MEASUREMENTS Principal Point Inconsistencies in principal points indicate tampering Metric Measurements Uses a priori knowledge of object geometry to determine forgery GEOMETRIC BASED METHODS: PRINCIPLE POINT & METRIC MEASUREMENTS

J. Fridrich, D. Soukal, and J J. Fridrich, D. Soukal, and J. Lukás, “Detection of copy move forgery in digital images,” in Proc. Digital Forensic Research Workshop, Aug. 2003. “Photo tampering throughout history”, 2004. H. Farid, “Image Forgery Detection”, Mar. 2009. A. Kharag, “#jumping back into the semester”, Instagram, Mar. 2018. Discrete Wavelet Transform on Color Picture Interpolation of Digital Still Camera, ResearchGate J. Stolworthy, “The Expendables 4 to move ahead without Sylvester Stallone”, Apr. 2017. M. Johnson, H. Farid, “Detecting Photographic Composites of People”, 2007 Image Sources

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