Vinicius Licks

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Quantization index modulation (QIM) watermarking has received a great deal of attention ever since the rediscovery of Costa’s result on codes with host-interference rejecting properties. While such embedding scheme exhibit considerable improvement in watermark capacity over its earlier predecessors, (e.g. spread-spectrum), their fragility to even the(More)
In this paper we study the effects of synchronization errors on the bit error rate performance of spatial domain image watermarking. For that, we introduce the concept of the Random Jitter Attack. This attack is characterized by the displacement of each pixel position by a random amount given by an arbitrary distribution, followed by interpolation over the(More)
OBJECTIVES This study aimed to develop and test a tool for low bone mass pre-screening by combining periapical radiographs with clinical risk factors. METHODS The study sample consisted of 60 post-menopausal women over 40 years of age who were referred for dental radiographs. These patients also had their bone mineral density measured at the lumbar spine(More)
1 Vinicius Licks, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS 90619-900, Brazil licks@ee.pucrs.br 2 Felipe Feldens, Syllabus e-Learning, Porto Alegre, RS 90035-077, Brazil syllabus@terra.com.br 3 Fabricio Ourique, Syllabus e-Learning, Porto Alegre, RS 90035-077, Brazil syllabus@terra.com.br 4 Daniel Fink, CRT Brasil Telecom,(More)
Scanning Eletron Microscopy (SEM) imaging has made it possible to obtain accurate infeiences about finctional intra-cellular events by the indirect observation of cell surface receptors’ aggregation. Such observations are made with the use of colloidal gold particles that bind to the surface of specific ligands that cross-link to the desired receptors.(More)
Max Costa original results on dirty paper codes have given the foundation for Quantizatin Index Modulation (QIM) based for digital image watermarking. However, the standard QIM methods can be greatly degraded by simple amplitude scaling attacks. In order to overcome this limitation, Angle Quantization Index Modulation (AQIM) schemes have been recently(More)