Djamel Brahmi

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Nowadays, access to information requires to manage effectively multimedia databases, and among challenges offered to scientific community since last decades, multimedia retrieval techniques (particularly images retrieval) are became an active research direction. Introduced to overcome the main drawbacks encountered by text-based images retrieval, which are(More)
A operational system devoted to the segmentation of virus-infected areas in the retina is described. I t means of a 3stage approach which involves image sampling, unsupervised coding and supervised classification. Unsupervised coding is provided by Principal Component Analj.sis whereas supervised classification is performed b1 a multilayr perceptron.(More)
We present the application of Quadri-Wave Lateral Shearing Interferometry (QWLSI), a wave front sensing technique, to characterize optical beams at infrared wavelengths from 2 to 16μm with a single instrument. We apply this technique to qualify optical systems dedicated to MWIR (λ within 3 and 5μm) and LWIR (λ within 8 and 14μm) wavelength ranges. The QWLSI(More)
We present the application of Quadri-Wave Lateral Shearing Interferometry (QWLSI), a wave front sensing technique, to characterize thermal infrared lenses for wavelengths within 8 and 14μm. Wave front sensing is not only a tool to quantify optical quality, but also to map the local (dust, scratches) or global possible defects. This method offers the crucial(More)
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