Evaluating Digital Photography for Lip Print Recording: Compatibility With Traditional Classification Systems

Direct digital photography for lip print recording is a recent trend, and there is a dearth of systematic research on the analysis of the recorded prints with existing clip print classification systems.

This study aims to compare the accuracy of the digital photographic method in lip print recording, comparing it with traditional methods, and assessing the suitability of commonly used lip print classification for analyzing lip prints recorded by photographic method.

A total of 72 participants aged between 20 and 26 were included. The lip print recording process involved photographing the lips without and with lipstick, followed by recording the lip print with cellophane tape on bond paper. The prints collected using the different methods were analyzed and compared for agreement, and the data were analyzed statistically.

Inter-observer reliability was high for all methods (>0.800). The distribution of lip print patterns differed across the methods, suggesting a potential influence of the recording technique. The agreement between the conventional method and both digital methods was moderate (kappa=0.449-0.517). The agreement between digital methods with and without enhancement was also moderate (kappa=0.718). Notably, digital photographs with enhancement tend to have a higher positive agreement for several lip print types.

Digital photography is a potential method for lip print recording. However, this study highlights the need for the calibration of lip print classification systems for digitally recorded lip prints. Further research is needed to refine the use of digital photography in forensic lip print analysis and to explore its integration with artificial intelligence for biometric identification.