Tutorials

The following tutorials and samples help explain how to use FotoForensics.

Error Level Analysis

• Error Level Analysis Tutorial: How ELA works and how to interpret results.
• Error Level Analysis Sample: A case study using ELA.

JPEG %

• Estimate JPEG Quality: Identifies the last JPEG quality level.

Metadata

• Metadata Analysis Tutorial: A description of metadata and how to use it for analysis.

Additional Reading

The following Hacker Factor blog entries provide additional information regarding image analysis and photo forensics:

• Mass Media Manipulations and Guidelines
  • Fake media photos from Russia's invasion of Georgia in 2008. Warning: Some pictures show may not be appropriate for young viewers.
  • Photographer guidelines for major media outlets
  • Tracing media photos from North Korea
• Image file structures
  • Overview of GIF, SWF, and JPEG file formats
  • JPEG lossy color transforms
  • JPEG and PNG comparison
  • JPEG bitstream encoding
  • Understanding JPEG application blocks
  • TIFF file format
  • TIFF encoding options
  • ICO file format
  • BMP format overloading
  • Photoshop and JPEG corruptions
  • DICOM medical imaging format overview
  • Flash (SWF) format overview
  • Comparison of online image hosting services
• Algorithms and Methods
  • Colorspace comparisons
  • Perceptual hashes for comparing images
  • Understanding Fast Fourier Transforms
  • Comparing Fast Fourier Transform libraries
  • Understanding the CMYK colorspace
  • Understanding terminology
  • Skin detection algorithms
  • Understanding 16-bit images
  • Decoding stereographic images
  • Kurtosis convergence and modification detection
  • Understanding the importance of image quality
  • Observation and an image quality checklist
• Applied Forensics
  • Debunking fake lottery tickets
  • More debunking fake lottery tickets
  • Using metadata to track down a suspect
  • Analyzing a leg 'tattoo'
  • Evaluating misleading political ads
  • Using metadata to find John McAfee
  • Evaluating Huge Chavez 'proof-of-life' photos