Forensic Image Analysis is the application of image science and domain expertise to interpret the content of an image and/or the image itself in legal matters. Major subdisciplines of Forensic Image Analysis with law enforcement applications include: Photogrammetry, Photographic Comparison, Content Analysis, and Image Authentication." (Scientific Working Group on Imaging Technologies)
It is not meant as an automatic tool that decide if an image is forged or not (that tool probably will never exist...), but as a companion in experimenting with various algorithms found in the latest research papers and workshops.
While many commercial solutions have high retail prices and often reserved to law enforcement and government agencies only, this toolset aims to be a both an extensible framework and a starting point for anyone interested in making experiments in this particular application of digital signal processing.
Modern Qt-based GUI with multiple tool window management
Support for many formats (JPEG, PNG, TIFF, BMP, WebP, PGM, PFM, GIF)
Highly responsive image viewer with real-time pan and zoom
Many state-of-the-art algorithms to try out interactively
Export both visual and textual results of the analysis
Extensive online help with explanations and tutorials
General
- Original Image: display the unaltered reference image for visual inspection
- File Digest: retrieve physical file information, crypto and perceptual hashes
- Hex Editor: open an external hexadecimal editor to show and edit raw bytes
- Similar Search: browse online search services to find visually similar images
Metadata
- Header Structure: dump the file header structure and display an interactive view
- EXIF Full Dump: scan through file metadata and gather all available information
- Thumbnail Analysis: extract optional embedded thumbnail and compare with original
- Geolocation Data: retrieve optional geolocation data and show it on a world map
Inspection
- Enhancing Magnifier: magnifying glass with enhancements for better identifying forgeries
- Channel Histogram: display single color channels or RGB composite interactive histogram
- Global Adjustments: apply standard image adjustments (brightness, hue, saturation, ...)
- Reference Comparison: open a synchronized double view for comparison with another picture
Detail
- Luminance Gradient: analyze horizontal/vertical brightness variations across the image
- Echo Edge Filter: use derivative filters to reveal artificial out-of-focus regions
- Wavelet Threshold: reconstruct image with different wavelet coefficient thresholds
- Frequency Split: split image luminance into high and low frequency components
Colors
- RGB/HSV Plots: display interactive 2D and 3D plots of RGB and HSV pixel values
- Space Conversion: convert RGB channels into HSV/YCbCr/Lab/Luv/CMYK/Gray spaces
- PCA Projection: use color PCA to project pixel onto most salient components
- Pixel Statistics: compute minimum/maximum/average RGB values for every pixel
Noise
- Noise Separation: estimate and extract different kind of image noise components
- Min/Max Deviation: highlight pixels deviating from block-based min/max statistics
- Bit Planes Values: show individual bit planes to find inconsistent noise patterns
- PRNU Identification: exploit sensor pattern noise introduced by different cameras
JPEG
- Quality Estimation: extract quantization tables and estimate last saved JPEG quality
- Error Level Analysis: show pixel-level difference against fixed compression levels
- Multiple Compression: use a machine learning model to detect multiple compression
- JPEG Ghost Maps: highlight traces of different compression levels in difference images
Tampering
- Contrast Enhancement: analyze color distribution to detect contrast enhancements
- Copy-Move Forgery: use invariant feature descriptors for cloned area detection
- Composite Splicing: exploit DCT statistics for automatic splicing zone detection
- Image Resampling: estimate 2D pixel interpolation for detecting resampling traces
Various
- Median Filtering: detect processing traces left by nonlinear median filtering
- Illuminant Map: estimate scene local light direction on estimated 3D surfaces
- Dead/Hot Pixels: detect and fix dead/hot pixels caused by sensor imperfections
- Stereogram Decoder: decode 3D images concealed in crossed-eye autostereograms
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