Classification of footwear outsole patterns using Fourier transform and local interest points.
Successful classification of questioned footwear has tremendous evidentiary value; the result can minimize the potential suspect pool and link a suspect to a victim, a crime scene, or even multiple crime scenes to each other. With this in mind, several different automated and semi-automated classification models have been applied to the forensic footwear recognition problem, with superior performance commonly associated with two different approaches: correlation of image power (magnitude) or phase, and the use of local interest points transformed using the Scale Invariant Feature Transform (SIFT) and compared using Random Sample Consensus (RANSAC). Despite the distinction associated with each of these methods, all three have not been cross-compared using a single dataset, of limited quality (i.e., characteristic of crime scene-like imagery), and created using a wide combination of image inputs. To address this question, the research presented here examines the classification performance of the Fourier-Mellin transform (FMT), phase-only correlation (POC), and local interest points (transformed using SIFT and compared using RANSAC), as a function of inputs that include mixed media (blood and dust), transfer mechanisms (gel lifters), enhancement techniques (digital and chemical) and variations in print substrate (ceramic tiles, vinyl tiles and paper). Results indicate that POC outperforms both FMT and SIFT+RANSAC, regardless of image input (type, quality and totality), and that the difference in stochastic dominance detected for POC is significant across all image comparison scenarios evaluated in this study.
West Virginia University, 208 Oglebay Hall, PO Box 6121, Morgantown, WV 26506, United States.
Nicole
N
Richetelli
Cedar Crest College, 100 College Drive, Allentown, PA 18104, United States.
Mackenzie C
MC
Lee
West Virginia University, 208 Oglebay Hall, PO Box 6121, Morgantown, WV 26506, United States.
Carleen A
CA
Lasky
West Virginia University, 208 Oglebay Hall, PO Box 6121, Morgantown, WV 26506, United States.
Madison E
ME
Gump
West Virginia University, 208 Oglebay Hall, PO Box 6121, Morgantown, WV 26506, United States. Electronic address: Jacqueline.Speir@mail.wvu.edu.
Jacqueline A
JA
Speir
D000465:Algorithms; D001769:Blood; D016208:Databases, Factual; D004391:Dust; D005456:Fluorescent Dyes; D044707:Forensic Sciences / Q000379:methods; D005583:Fourier Analysis; D005840:Gentian Violet; D006801:Humans; D007091:Image Processing, Computer-Assisted; D010363:Pattern Recognition, Automated; D012775:Shoes; D013499:Surface Properties
D004391:Dust; D005456:Fluorescent Dyes; C475159:leucocrystal violet; D005840:Gentian Violet
Footwear; Fourier–Mellin transform; Phase only correlation; RANSAC; SIFT