title: Correcting the planar perspective projection in geometric structures applied to forensic facial analysis.
abstract: The process of forensic facial analysis may be founded on several scientific techniques and imaging modalities, such as digital signal processing, photogrammetry and craniofacial anthropometry. However, one of the main limitations in this analysis is the comparison of images acquired with different angles of incidence. The present study aimed to explore a potential approach for the correction of the planar perspective projection (PPP) in geometric structures traced from the human face. A technique for the correction of the PPP was calibrated within photographs of two geometric structures obtained with angles of incidence distorted in 80°, 60° and 45°. The technique was performed using ImageJ®1.46r (National Institutes of Health, Bethesda, Maryland). The corrected images were compared with photographs of the same object obtained in 90° (reference). In a second step, the technique was validated in a digital human face created using MakeHuman®1.0.2 (Free Software Foundation, Massachusetts, EUA) and Blender®2.75 (Blender®Foundation, Amsterdam, Nederland) software packages. The images registered with angular distortion presented a gradual decrease in height when compared to the reference. The digital technique for the correction of the PPP is a valuable tool for forensic applications using photographic imaging modalities, such as forensic facial analysis.
authors: Forensic expert, Department of Criminalistics, General Institute of Forensic Expertises, State Public Safety Office, Rio Grande do Sul, Brazil; Forensic Dentistry, Department of Social Dentistry, Faculty of Dentistry, University of São Paulo, Brazil. Electronic address: rosanebaldasso@gmail.com.
authors: Rosane Pérez
authors: RP
authors: Baldasso
authors: Department of Bioarchaeology - National Museum, Federal University of Rio de Janeiro, Brazil ​; Forensic Dentistry, Faculty of Dentistry, University Salgado de Oliveira, Niterói, Brazil.
authors: Rachel Lima Ribeiro
authors: RLR
authors: Tinoco
authors: Department of Forensic Dentistry, Brazilian Dental Association-Section of Rio Grande do Sul, Brazil.
authors: Cristina Saft Matos
authors: CSM
authors: Vieira
authors: Forensic Dentistry, Department of Social Dentistry, Faculty of Dentistry, University of São Paulo, Brazil; Department of Forensic Dentistry, Brazilian Dental Association-Section of Rio Grande do Sul, Brazil.
authors: Mário Marques
authors: MM
authors: Fernandes
authors: Forensic Dentistry, Department of Social Dentistry, Faculty of Dentistry, University of São Paulo, Brazil.
authors: Rogério Nogueira
authors: RN
authors: Oliveira
mesh_terms: D059925:Anatomic Landmarks; D005145:Face / Q000033:anatomy & histology*; D018732:Forensic Anthropology / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D010363:Pattern Recognition, Automated; D010781:Photography; D012984:Software
keywords: Anthropometry; Facial recognition; Forensic sciences; Image processing