102,109 research outputs found
JPEG compression anti-forensics based on first significant digit distribution
No full textTraces left by lossy compression processes have been widely studied in digital image forensics. In particular, the artifacts produced by JPEG compression have been characterized and exploited both in forensic methods and counter-forensic attacks. In this paper, we propose a novel anti-forensic procedure, aimed at concealing the traces of single JPEG compression by recovering the original distribution of first significant digits (FSD) of the DCT coefficients. We analyze the performance of our method and compare it with anti-forensic attacks reported in the literature in terms of quality of the resulting image. In addition, we prove the effectiveness of our approach as counter-forensic processing by measuring its impact on the performance of two different forensic tools, applied after the anti-forensic action
Impact of Contrast Modification on Human Feeling: an Objective and Subjective Assessment
No full textImages are powerful means of communication. Adding images to documents, websites, magazines, helps attracting the attention and providing an immediate feeling about the content of the document itself. At the same time, images can be used to influence the attitude of the reader. In the digital era it is easier than ever to create and share multimedia documents making extensive use of visual data. Furthermore, it is extremely easy to modify and adapt the images in order to make them more suitable to convey a concept. These modifications may simply consist in focusing the attention on a specific part of the image, to heavier manipulations such as changing the visual appearance or the contents to bias the opinion of the observer. This creates a rising interest for the availability of automatic blind tools able to detect possible modifications of images, and to correlate these modifications with the relevant impact on the viewer. This paper proposes an example of application of these concepts that exploits a tool for automatic detection of contrast modifications and analyzes their impact on human feeling. The results of instrumental and subjective studies are presented and discusse
Potere di grazia tra "legge Boato" e inerzia presidenziale
No full textAnalisi critica del disegno di legge "Boato" mirante ad introdurre una nuova disciplina per la concessione della grazia. Indicazini delle ragioni che militerebbero, invece, a favore di un conflitto di attribuzioni, in materia di clemenza individuale, promosso dal Presidente della Repubblica contro il Governo per l'atteggiamento ostruzionistico del Guardasigilli
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