Παρασκευή, 31 Αυγούστου 2007
Τετάρτη, 22 Αυγούστου 2007
In the new Issue of Forensic Science International (Volume 172, Issue 1, 2 October 2007, Pages 10-16 ), R. Marquisa, F. Taronia, S. Bozzab & M. Schmittbuhlc rpresent a paper titled: "Size influence on shape of handwritten characters loops".
In the practice of forensic handwriting experts, the size of the writing on a questioned document may be different from that of known samples. In this study, the hypothesis of shape invariance of handwritten closed loops across size increasing was tested. A Fourier methodology was applied to 2325 small letters (591 a loops, 547 d loops, 596 o loops and 591 q loops) and 692 enlarged letters (162 a loops, 173 d loops, 173 o loops and 184 q loops), in a population of 13 writers who were asked to write letters in their usual size and about three times larger. Most of the writers presented similar modifications when increasing the size of the loops; they produced enlarged loops significantly more round and less slanted towards the right or the left. Furthermore, a discrimination was demonstrated between the writers on the basis of the enlarged loops, with a correct classification rate superior to 90%, whatever the letter (a, d, o or q). A classification of the enlarged loops in their corresponding writer was then possible. On the contrary, when comparing the enlarged loops to the small ones, almost one half of the enlarged loops were allocated to a wrong writer. Shape invariance was thus not supported for this particular application. Consequently, when comparing documents with a different writing size, differences in loops shape should be interpreted cautiously because they may be due to a different writer, but they may also be due to an enlargement of the loops. Therefore, reference material of similar writing size to that of the questioned writing should be requested for the comparison of handwritten loops.
Παρασκευή, 10 Αυγούστου 2007
Στο καινούργιο e-τευχος του Forensic Science International (Volume 171, Issue 2-3, 13 September 2007, Pages 180-189 ), οι Babak Mahdian και Stanislav Saic παρουσιάζουν μια εργασία με τίτλο: "Detection of copy-move forgery using a method based on blur moment invariants".
In the new Issue of Forensic Science International (Volume 171, Issue 2-3, 13 September 2007, Pages 180-189 ), Babak Mahdian & Stanislav Saic present a paper titled: "Detection of copy–move forgery using a method based on blur moment invariants".
Περίληψη/Abstract:In our society digital images are a powerful and widely used communication medium. They have an important impact on our life. In recent years, due to the advent of high-performance commodity hardware and improved human–computer interfaces, it has become relatively easy to create fake images. Modern, easy to use image processing software enables forgeries that are undetectable by the naked eye. In this work we propose a method to automatically detect and localize duplicated regions in digital images. The presence of duplicated regions in an image may signify a common type of forgery called copy–move forgery. The method is based on blur moment invariants, which allows successful detection of copy–move forgery, even when blur degradation, additional noise, or arbitrary contrast changes are present in the duplicated regions. These modifications are commonly used techniques to conceal traces of copy–move forgery. Our method works equally well for lossy format such as JPEG. We demonstrate our method on several images affected by copy–move forgery.
Σύνδεσμος/ Link: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6W-4MJBTMV-1&_user=10&_coverDate=09%2F13%2F2007&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=92226831e72dc0baba6bf5b34d7f952f
Παρασκευή, 3 Αυγούστου 2007
Γερμανός Προγραμματιστής καταφέρνει να αντιγραψει τα καινούργια ηλεκτρονικά διαβατήρια των Η.Π.Α. & άλλων χωρών.
A German computer security consultant has shown that he can clone the electronic passports that the United States and other countries are beginning to distribute this yearWired: Hackers Clone E-Passports http://www.wired.com/science/discoveries/news/2006/08/71521