3D characterization of hot metallic shells during industrial forging

During industrial forging of hot metallic shells, it is necessary to regularly measure the dimensions of the parts, especially the inner and outer diameters and the thickness of the walls. A forging sequence lasts 2 h or more during which the diameter of the shell is regularly measured in order to decide when to stop the forging process. For better working conditions, for the safety of the blacksmiths, and for a faster and more accurate measurement, we have developed a novel system based on two commercially available time of flight laser scanners for the measurement of the diameters of hot cylindrical metallic shells during the forging process. The advantages of using laser scanners are that they can be placed very far from the hot shell, more than 15 m, while at the same time giving an accurate point cloud from which three-dimensional views of the shell can be reconstructed and diameter measurements done. Moreover, more accurate measurement is achieved in less time with the laser system than with the conventional method using a large ruler. The system has been successfully used to measure the diameters of hot cylindrical metallic shells.     

Automatic source scanner identification using 1D convolutional neural network

In this digital world, digitized documents can be considered original or a piece of evidence; checking the authenticity of any suspicious image has become an unavoidable concern to preserve the trust in its legitimacy. However, identifying the source of a digital image without any prior embedded information is a very challenging task. This paper proposes a novel one-dimensional convolutional neural network (1D-CNN) model to solve the source scanner identification (SSI) problem blindly. Unlike traditional methods based on handcrafted features, the proposed framework can dynamically learn and extract scanner device-specific features. This work, comprised of the 1D-CNN and a support vector machine (SVM) as a classifier, was trained on nine scanners of different brands and models. The experimental result shows that our model achieves 98.15% accuracy on full images and overall accuracy of 93.13% on segments from test images, outperforming other state-of-art approaches. Our model also proves to be able to distinguish between scanners of the same model. Furthermore, the SVM classifier improved the 1D-CNN accuracy by approximately 3% compared to its original configuration.

     

A joint encryption/watermarking algorithm for verifying the reliability of medical images: application to echographic images

In this paper we propose a joint encryption/watermarking algorithm for the purpose of protecting medical images. The proposed solution gives access to the outcomes of the image integrity and of its origins as its attachment to one patient even if the image is stored encrypted. In this study, the given solution combines the RC4 stream cipher and two substitutive watermarking modulations: the Least Significant Bit Method and the Quantization Index Modulation. If watermarking and encryption are conducted jointly at the protection stage, watermark extraction and decryption can be applied independently. Experimental results achieved on 8 bits encoded echographic images illustrate the overall performances of the proposed scheme. At least, a capacity rate of 1 and 0.5 bits of message per pixel of image can be embedded in the spatial and the encrypted domains respectively, with a peak signal to noise ratio greater than 49 dB.     

Real-time analysis of cataract surgery videos using statistical models

Multimedia Tools and Applications - The automatic analysis of the surgical process, from videos recorded during surgeries, could be very useful to surgeons, both for training and for acquiring new...     

Measurement of the saturated dislocation pinning force in hydrogenated nickel and nickel base alloys

Static strain ageing experiments are used to measure the saturated dislocation pinning force as a function of the hydrogen concentration in hydrogenated nickel and binary nickel—16 wt% chromium. The role of hydrogen transport by mobile dislocations on hydrogen embrittlement is demonstrated.     

Images médicales, sécurité et tatouage

In this article, security issues for medical information and technical solutions to protect these data in Medical Information Systems are examined. We then introduce the watermarking as a complementary security tool. The relevance of this new technology in healthcare is discussed from the application viewpoints and through the implementation constraints. A solution is proposed, based on an original approach which consists in watermarking image areas that are not relevant for the diagnosis. This system is transparent to the user and allows image integrity control. In addition, it provides information on the location of potential alterations and an evaluation of image modifications which is of major importance in a medico-legal framework. An example using head Magnetic Resonance Imaging illustrates the overall method.