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: BEREIN 15 UNCLASSIFIED _ _ Abstract Viewer ~ ; ° aia @: E le-l0-2008 BY o032e4 UC “yy Page 1 of I Abstract Viewer Wire Analysis Using Fast Fourier Transform Processing Techniques in Paper Identification Cases. Mr. Neil Holland (Scientific Document Services Pty. Ltd., Australia) Email Address: sds@mpx.com.au The methods for physical paper testing and the chemical analysis of paper are well documented throughout the literature when examining paper involved in forensic cases. Within this literature the use of X-rays, Beta Rays, Oblique and Transmitted light can provide the examiner valuable information about paper formation and in particular about surface and fiber characteristics of the paper. A study of the wire marks where visible can provide additional information but in those papers where they are difficult to examine, the use of a technique to capture and process the images to reveal the wire marks can be extremely beneficial. Initially images of the paper formation are captured using oblique light or Beta Ray (preferred) techniques and the resultant images are scanned and then processed using Fast Fourier Transform (FFT) analysis. This technique allows for the pattern of the wire marks to be captured and the resultant Power Spectrums (frequency domain) can be compared with control samples fram known sources (mills} or compared to other paper exhibits. The Power Spectrum (frequency domain) and the inverse (retransformation) patterns can be compared to distinguish papers produced on different wires thus differentiating the papers. Conversely the results may provide additional information that may establish that two or more papers are indistinguishable. : : http://Awww.anzfss2004.org.nz/cgi-bin/V iewAbstracts.cgi?paperid=49 3/6/2005