Forged seal detection based on the seal overlay metric

Autor: Joong Lee, Bong-Woo Lee, Joong-Suk Seo, Oc-Yeub Jeon, Young-Soo Lee, Ki-Woong Moon, Seong G. Kong, Jong Hyun Han
Rok vydání: 2012
Předmět:
Zdroj: Forensic Science International. 214:200-206
ISSN: 0379-0738
DOI: 10.1016/j.forsciint.2011.08.009
Popis: This paper describes a method for verifying the authenticity of a seal impression imprinted on a document based on the seal overlay metric, which refers to the ratio of an effective seal impression pattern and the noise in the neighborhood of the reference impression region. A reference seal pattern is obtained by taking the average of a number of high-quality impressions of a genuine seal. A target seal impression to be examined, often on paper with some background texts and lines, is segmented out from the background by an adaptive threshold applied to the histogram of color components. The segmented target seal impression is then spatially aligned with the reference by maximizing the count of matching pixels. Then the seal overlay metric is computed for the reference and the target. If the overlay metric of a target seal is below a predetermined limit for the similarity to the genuine, then the target is classified as a forged seal. To further reduce the misclassification rate, the seal overlay metric is adjusted by the filling rate, which reflects the quality of inked pattern of the target seal. Experiment results demonstrate that the proposed method can detect elaborate seal impressions created by advanced forgery techniques such as lithography and computer-aided manufacturing.
Databáze: OpenAIRE
Externí odkaz: