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Conference Paper
An Unsupervised Bayesian Approach for the Joint Reconstruction and Classification of Cutaneous Reflectance Confocal Microscopy Images
In Proc. European Signal and Image Processing Conference (EUSIPCO), Kos Islands, Greece, August 28-September 2, 2017.
This paper studies a new Bayesian algorithm for the joint reconstruction and classification of reflectance confocal microscopy (RCM) images, with application to the identification of human skin lentigo. The proposed Bayesian approach takes advantage of the distribution of the multiplicative speckle noise affecting the true reflectivity of these images and of appropriate priors for the unknown model parameters. A Markov chain Monte Carlo (MCMC) algorithm is proposed to jointly estimate the model parameters and the image of true reflectivity while classifying images according to the distribution of their reflectivity. Precisely, a Metropolis-within-Gibbs sampler is investigated to sample the posterior distribution of the Bayesian model associated with RCM images and to build estimators of its parameters, including labels indicating the class of each RCM image. The resulting algorithm is applied to synthetic data and to real images from a clinical study containing healthy and lentigo patient.
Signal and image processing / Earth observation
Kernel Density-Based Particle Filter Algorithm for State and Time-Varying Parameter Estimation in Nonlinear State-Space Model
In Proc. European Signal and Image Processing Conference (EUSIPCO), Kos Islands, Greece, August 28-September 2, 2017.
Signal and image processing / Localization and navigation
Journal Paper
Unsupervised Nonlinear Spectral Unmixing Based on a Multilinear Mixing Model
IEEE Transactions on Geoscience and Remote Sensing, vol. 55, issue 8, pp. 4534-4544, August, 2017.
In the community of remote sensing, nonlinear mixture models have recently received particular attention in hyperspectral image processing. In this paper, we present a novel nonlinear spectral unmixing method following the recent multilinear mixing model of Heylen and Scheunders, which includes an infinite number of terms related to interactions between different endmembers. The proposed unmixing method is unsupervised in the sense that the endmembers are estimated jointly with the abundances and other parameters of interest, i.e., the transition probability of undergoing further interactions. Nonnegativity and sum-to-one constraints are imposed on abun- dances while only nonnegativity is considered for endmembers. The resulting unmixing problem is formulated as a constrained nonlinear optimization problem, which is solved by a block coordinate descent strategy, consisting of updating the end- members, abundances, and transition probability iteratively. The proposed method is evaluated and compared with existing linear and nonlinear unmixing methods for both synthetic and real hyperspectral data sets acquired by the airborne visible/infrared imaging spectrometer sensor. The advantage of using nonlinear unmixing as opposed to linear unmixing is clearly shown in these examples.
Signal and image processing / Earth observation
A Data-Driven Approach For Actuator Servo Loop Failure Detection
IFAC-PapersOnLine, vol. 50, Issue 1, pp. 13544-13549, July, 2017.
This paper studies a data-driven approach to detect faults in flight control systems of civil aircraft. A particular class of failures, referred to as Oscillatory Failure Cases (OFC), impacting the actuator servo loop has motivated the authors to consider a data-driven approach based on distance and correlation measures (see reference [Goupil et al.(2016). A data-driven approach to detect faults in the Airbus flight control system. IFAC-PapersOnLine, 49(17), 52-57] of this paper) leading to promising results compared to the state-of-the-art methods based on analytical redundancy. The present paper extends the formulation and the results of the considered OFC detection approach investigating Support Vector Machine (SVM) techniques to define a more accurate detector based on distance and correlation measures.
Signal and image processing / Aeronautical communication systems and Space communication systems
Conference Paper
Missing Data Reconstruction and Anomaly Detection in Crop Development using Agronomic Indicators Derived from Multispectral Satellite Images
In Proc. IEEE International Geoscience & Remote Sensing Symposium (IGARSS), Fort Worth, Texas, USA, July 23-28, 2017.
Signal and image processing / Earth observation
Deep learning for cloud detection
In Proc. International Conference of Pattern Recognition Systems (ICPRS), Madrid, Spain, July 11-13, 2017.
The SPOT 6-7 satellite ground segment includes a systematic and automatic cloud detection step in order to feed a catalogue with a binary cloud mask and an appropriate condence measure. However, current approaches for cloud detection, that are mostly based on machine learning and hand crafted features, have shown lack of robustness. In other tasks such as image recognition, deep learning methods have shown outstanding results outperforming many state-of-the-art methods. These methods are known to produce a powerful representation that can capture texture, shape and contextual information. This paper studies the potential of deep learning methods for cloud detection in order to achieve state-of-the-art performance. A comparison between deep learning methods used with classical handcrafted features and classical convolutional neural networks is performed for cloud detection. Experiments are conducted on a SPOT 6 image database with various landscapes and cloud coverage and show promising results.
Signal and image processing / Earth observation
A Data-Driven Approach For Actuator Servo Loop Failure Detection
In Proc. International Federation of Automatic Control (IFAC), Toulouse, France, July 9-14, 2017.
This paper studies a data-driven approach to detect faults in flight control systems of civil aircraft. A particular class of failures, referred to as Oscillatory Failure Cases (OFC), impacting the actuator servo loop has motivated the authors to consider a data-driven approach based on distance and correlation measures (see reference [Goupil et al.(2016). A data-driven approach to detect faults in the Airbus flight control system. IFAC-PapersOnLine, 49(17), 52-57] of this paper) leading to promising results compared to the state-of-the-art methods based on analytical redundancy. The present paper extends the formulation and the results of the considered OFC detection approach investigating Support Vector Machine (SVM) techniques to define a more accurate detector based on distance and correlation measures.
Signal and image processing / Aeronautical communication systems and Space communication systems
Shape Effects on Sampling of Stationary Processes
In Proc. Sampling Theory and Applications (SampTA), 12th International Conference, Tallinn, ESTONIA, July 3-7, 2017.
Acquisition devices play an important role in digital signal processing. The possibility of a perfect reconstruction is demonstrated in regular as well as irregular sampling when the number of samples in the observation interval is high enough in function of the bandwidth of the sampled signal (length of the support of the spectrum). In the case of high sampling rates, imperfections of acquisition devices can introduce non negligible errors (when the acquisition duration of a given sample becomes not negligible in comparison with the sampling period (or mean sampling period in the case of irregular sampling). In this paper, explicit method is proposed to take into account imperfections of the sampling device in order to improve the reconstruction of the signal. The proposed method is applicable for deterministic functions and random processes in the case of regular sampling, as well as irregular sampling.
Signal and image processing / Space communication systems
On Sparse Graph Coding for Coherent and Noncoherent Demodulation
In Proc. International Symposium on Information Theory (ISIT), Aachen, Germany, June 25-30, 2017.
In this paper, we consider a bit-interleaved coded modulation scheme (BICM) composed of an error correcting code serially concatenated with a M-ary non linear modulation with memory. We first compare demodulation strategies for both the coherent and the non coherent cases. Then, we perform an asymptotic analysis and try to show that the design of coding schemes performing well for both the coherent and the non coherent regimes should be done carefully when considering sparse graph based codes such as low-density parity-check (LDPC) codes. It will be shown that optimized coding schemes for the non coherent setting can perform fairly well when using coherent demodulation, while on the contrary, optimized coding schemes for the coherent setting may lead to ”non stable” coding schemes in the non coherent setting.
Digital communications / Space communication systems
Improving Synthetic Aperture Radar Detection using the Automatic Identification System
In Proc. 18th International Radar Symposium (IRS) , Prague, Czech Republic, June 28-30, 2017.
This paper studies a maritime vessel detection method based on the fusion of data obtained from two different sensors, namely a synthetic aperture radar (SAR) and an automatic identification system (AIS) embedded in a satellite. In this work we propose a detector that uses the vessel position provided by the AIS system to improve the radar detection performance. The problem is handled by a generalized likelihood ratio test leading to a detector whose test statistics has a simple closed form expression. The distribution of the test statistics under the hypotheses is also determined, allowing theoretical and simulated receiver operational characteristics (ROCs) to be compared. Our results indicate that the proposed method improves detection performance and motivates the joint use of raw radar data with AIS demodulated information for ship detection.
Signal and image processing / Earth observation
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