Writer Identification
Lewis Griffin & Andrew Newell
Computer Science, CoMPLEXUniversity College London
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Example 2: different language, different textExample 1: same language, different textExample 0: same language, same text
http://www.moralesforensics.com/identification.htm
Macro Features
Micro Features
• Definitive, highly-cited publication.
• Basis of the CedarFox document analysis software package.
• Analyzed the uniqueness of the macro and micro features used by experts.
Task: pick out the sample by the same writer from a set of 200 writers(same language, same text).
Srihari et al. (CedarFox?)
Using expert-style macro features, 40% correct.
Using expert-style micro features, 86% correct.
With macro & micro features,91% correct.
Newell & Griffin
Using our macro features,95% correct(on same language, different text).
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Basic Image Features (BIFs)A computational model
of Human Vision
Our Primary Research Area…
Sand grain appearance under electron microscopy reveals distinctive, geographically specific textures
Basic Image Features make the texture differences obvious to a computer
…looked sufficiently promising when used to characterize the texture of sand grain images, that…
Electron Microscopy of Sand Grains weathered at different wind speeds
Newell, A. J., Morgan, R. M., Griffin, L. D., Bull, P. A., Marshall, J. R., & Graham, G. (2012). Automated Texture Recognition of Quartz Sand Grains for Forensic Applications. Journal of Forensic Sciences.
…the Atomic Weapons Establishment funded a project to investigate the forensic potential of our texture analysis method for particulate identification
Not knowing the importance experts attach to comparing individual letters we tried our texture approach…
Summary
• Computers can be more accurate than experts…
• …by using methods that do not mimic those experts.
• The Newell-Griffin method is currently world-leading.
• It is based on a method of texture analysis.
• That also works for quartz grains, biomedical image analysis,general-purpose object recognition,…
• That derives from a model of how human vision works.
• We are keen to take advice on this handwriting work…
• …and to find other forensic applications of our image analysis/recognition expertise.