Compression Effects on Security Document Images

摘要

Compression effects for security documents can have an important impact on optical document inspection in border control: High-frequency information, usually suffering from compression artefacts, is difficult to reproduce and an inherent security feature. Where the processing of uncompressed data is not an option, e.g., for mobile equipment with limited processing bandwidth or large template databases of prototype security regions, it is useful to study compression properties of this particular type of data. We present an evaluation of three state-of-the-art lossy image compression standards applied to acquisitions of passports from nine security document readers in VIS, UV, and IR spectra. In particular, we tested JPEG (ISO/IEC 10918-1, 1994), JPEG-XR (ISO/IEC 29199-2, 2010), and JPEG 2000 (ISO/IEC 15444-1, 2000). Results show that JPEG-XR outperforms the other approaches for security documents across the range of tested devices and spectra.