title: Design of one-dimensional power spectrum using two-dimensional fast Fourier transform for discrimination of paper-based kraft tapes.
abstract: A novel type of spectrum, the one-dimensional power spectrum (1D-PS), was designed for the discrimination of adhesive packing tapes, i.e., kraft tapes. The 1D-PS offered complementary information to that provided by the improved two-dimensional PS (2D-PS), which was calculated using our previously established image processes combined with a two-dimensional fast Fourier transform (2D-FFT) to obtain information about the spatial periodicity within kraft tapes. The 1D-PS was calculated using a three-step image process: (i) the 2D-FFT was applied to 50 randomly selected areas in a transmitted light image; (ii) the obtained 2D-PSs were accumulated without applying a logarithmic transform; (iii) the wavenumber and the maximum intensity were plotted on the x-axis and y-axis, respectively. Through an intra-roll comparison, the 1D-PSs collected from single rolls showed similar profiles. In an inter-roll comparison, the 1D-PSs from 50 commercially available brand-name products were classified into 29 groups. The 1D-PSs contained other useful information than that provided by the improved 2D-PSs: they presented more peaks and absolute intensity with a wider range. The 1D-PSs enabled us to compare the spectra quickly and easily, owing to their unchanging profiles regardless of the orientation of the scanned images. A combined use of the 1D-PSs with the improved 2D-PSs-both spectrum types being convenient, rapid, non-destructive, and applicable to dirty and/or damaged samples-could further improve the identification of kraft tapes.
authors.affiliation: Forensic Science Laboratory, Miyagi Pref. Police H.Q., 3-1, Tsukasaki, Morigou, Rifu-cho, Miyagi-gun, Miyagi 981-0103, Japan. Electronic address: sara.sasaoka@gmail.com.
authors.forename: Sara
authors.initials: S
authors.lastname: Sasaoka
authors.affiliation: Forensic Science Laboratory, Miyagi Pref. Police H.Q., 3-1, Tsukasaki, Morigou, Rifu-cho, Miyagi-gun, Miyagi 981-0103, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Saito
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-shi, Chiba 260-8675, Japan.
authors.forename: Kenjirou
authors.initials: K
authors.lastname: Higashi
authors.affiliation: Department of Manufacturing Pharmacy, Faculty of Pharmacy, Mahidol University, 447, Sri Ayudhya Road, Ratchatewi, Bangkok 10400, Thailand.
authors.forename: Waree
authors.initials: W
authors.lastname: Limwikrant
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-shi, Chiba 260-8675, Japan.
authors.forename: Kunikazu
authors.initials: K
authors.lastname: Moribe
authors.affiliation: National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa-shi, Chiba 277-0882, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-shi, Chiba 260-8675, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Yamamoto
keywords: Adhesive tapes; FFT; Non-destructive; Transmitted light images