1. IMAGE FORGERY DETECTION
Justin Siao
IMAGE FORGERY DETECTION

2. PIXEL BASED
FORMAT BASED
CAMERA BASED
PHYSICS BASED
GEOMETRIC BASED
OUTLINE

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

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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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
“Photo tampering throughout history”, 2004.
H. Farid, “Image Forgery Detection”, Mar
A. Kharag, “#jumping back into the semester”, Instagram, Mar
Discrete Wavelet Transform on Color Picture Interpolation of Digital Still Camera, ResearchGate
J. Stolworthy, “The Expendables 4 to move ahead without Sylvester Stallone”, Apr
M. Johnson, H. Farid, “Detecting Photographic Composites of People”, 2007
Image Sources

11. QUESTIONS: