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Neji N.,Equipe Vision | Neji N.,University of Sfax | Jridi M.,Equipe Vision | Alfalou A.,Equipe Vision | Masmoudi N.,University of Sfax
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

This paper presents an optimized H.264/AVC coding system for HDTV displays based on a typical flow with high coding efficiency and statics adaptivity features. For high quality streaming, the codec uses a Binary Arithmetic Encoding/Decoding algorithm with high complexity and a JVCE (Joint Video compression and encryption) scheme. In fact, particular attention is given to simultaneous compression and encryption applications to gain security without compromising the speed of transactions [1]. The proposed design allows us to encrypt the information using a pseudo-random number generator (PRNG). Thus we achieved the two operations (compression and encryption) simultaneously and in a dependent manner which is a novelty in this kind of architecture. Moreover, we investigated the hardware implementation of CABAC (Context-based adaptive Binary Arithmetic Coding) codec. The proposed architecture is based on optimized binarizer/de-binarizer to handle significant pixel rates videos with low cost and high performance for most frequent SEs. This was checked using HD video frames. The obtained synthesis results using an FPGA (Xilinx's ISE) show that our design is relevant to code main profile video stream. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.


Ouerhani Y.,Actris Brest | Alfalou A.,Equipe Vision | Desthieux M.,University of Western Brittany | Brosseau C.,University of Western Brittany
Optics and Lasers in Engineering | Year: 2016

We present a three-step approach based on the commercial VIAPIX® module for road traffic sign recognition and identification. Firstly, detection in a scene of all objects having characteristics of traffic signs is performed. This is followed by a first-level recognition based on correlation which consists in making a comparison between each detected object with a set of reference images of a database. Finally, a second level of identification allows us to confirm or correct the previous identification. In this study, we perform a correlation-based analysis by combining and adapting the Vander Lugt correlator with the nonlinear joint transformation correlator (JTC). Of particular significance, this approach permits to make a reliable decision on road traffic sign identification. We further discuss a robust scheme allowing us to track a detected road traffic sign in a video sequence for the purpose of increasing the decision performance of our system. This approach can have broad practical applications in the maintenance and rehabilitation of transportation infrastructure, or for drive assistance. © 2016.


Aldossari M.,Equipe Vision | Alfalou A.,Equipe Vision | Brosseau C.,University of Western Brittany
Optics Express | Year: 2014

This study presents and validates an optimized method of simultaneous compression and encryption designed to process images with close spectra. This approach is well adapted to the compression and encryption of images of a time-varying scene but also to static polarimetric images. We use the recently developed spectral fusion method [Opt. Lett. 35, 1914-1916 (2010)] to deal with the close resemblance of the images. The spectral plane (containing the information to send and/or to store) is decomposed in several independent areas which are assigned according a specific way. In addition, each spectrum is shifted in order to minimize their overlap. The dual purpose of these operations is to optimize the spectral plane allowing us to keep the low- and high-frequency information (compression) and to introduce an additional noise for reconstructing the images (encryption). Our results show that not only can the control of the spectral plane enhance the number of spectra to be merged, but also that a compromise between the compression rate and the quality of the reconstructed images can be tuned. We use a root-mean-square (RMS) optimization criterion to treat compression. Image encryption is realized at different security levels. Firstly, we add a specific encryption level which is related to the different areas of the spectral plane, and then, we make use of several random phase keys. An in-depth analysis at the spectral fusion methodology is done in order to find a good trade-off between the compression rate and the quality of the reconstructed images. Our new proposal spectral shift allows us to minimize the image overlap. We further analyze the influence of the spectral shift on the reconstructed image quality and compression rate. The performance of the multiple-image optical compression and encryption method is verified by analyzing several video sequences and polarimetric images. © 2014 Optical Society of America.


Jridi M.,Equipe Vision | Ouerhani Y.,Equipe Vision | Alfalou A.,Equipe Vision
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

In this paper, we defined a low complexity 2D-DCT architecture. The latter will be able to transform spatial pixels to spectral pixels while taking into account the constraints of the considered compression standard. Indeed, this work is our first attempt to obtain one reconfigurable multistandard DCT. Due to our new matrix decomposition, we could define one common 2D-DCT architecture. The constant multipliers can be configured to handle the case of RealDCT and/or IntDCT (multiplication by 2). Our optimized algorithm not only provides a reduction of computational complexity, but also leads to scalable pipelined design in systolic arrays. Indeed, the 8 × 8 StdDCT can be computed by using 4×4 StdDCT which can be obtained by calculating 2×2 StdDCT. Besides, the proposed structure can be extended to deal with higher number of N (i.e. 16 × 16 and 32 × 32). The performance of the proposed architecture are better when compared with conventional designs. In particular, for N = 4, it is found that the proposed design have nearly third the area-time complexity of the existing DCT structures. This gain is expected to be higher for a greater size of 2D-DCT. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.


Ouerhani Y.,Equipe Vision | Jridi M.,Equipe Vision | Alfalou A.,Equipe Vision | Brosseau C.,European University of Brittany
Optics Communications | Year: 2013

The key outcome of this work is to propose and validate a fast and robust correlation scheme for face recognition applications. The robustness of this fast correlator is ensured by an adapted pre-processing step for the target image allowing us to minimize the impact of its (possibly noisy and varying) amplitude spectrum information. A segmented composite filter is optimized, at the very outset of its fabrication, by weighting each reference with a specific coefficient which is proportional to the occurrence probability. A hierarchical classification procedure (called two-level decision tree learning approach) is also used in order to speed up the recognition procedure. Experimental results validating our approach are obtained with a prototype based on GPU implementation of the all-numerical correlator using the NVIDIA GPU GeForce 8400GS processor and test samples from the Pointing Head Pose Image Database (PHPID), e.g. true recognition rates larger than 85% with a run time lower than 120 ms have been obtained using fixed images from the PHPID, true recognition rates larger than 77% using a real video sequence with 2 frame per second when the database contains 100 persons. Besides, it has been shown experimentally that the use of more recent GPU processor like NVIDIA-GPU Quadro FX 770M can perform the recognition of 4 frame per second with the same length of database. © 2012 Elsevier B.V.


Alfalou A.,Equipe Vision | Brosseau C.,University of Western Brittany
Optics Communications | Year: 2013

We report a method of simultaneous compression and encryption of multiple images based on a specific spectral fusion. This method is able to manipulate target images with close spectral characteristics. For that purpose, we introduce an optimized algorithm for the task of simultaneously compressing and encrypting phase-shifting digital holograms (PSIDH) for three-dimensional object reconstruction. This technique is based on a spectral fusion, without overlapping, of interference patterns I corresponding to phase shifts. We first divide the spectral plane into several areas and optimize the bandwidth of the spectral domain. Each area is affected to a spectrum of an intensity pattern IPSIDH. A two-level encryption of these patterns is realized. First, we apply a discrete cosine transform (DCT) spectral fusion after addition of an input key image. Then, each DCT-spectral interference pattern is multiplied with a specific random intensity function to uniformly distribute the spectral intensity. To validate our approach, many numerical simulations are performed. The simplicity and robustness of our tests make this algorithm appealing for object reconstruction. © 2013 Elsevier B.V.


Alfalou A.,Equipe Vision | Brosseau C.,University of Western Brittany | Kaddah W.,Equipe Vision
Optics Communications | Year: 2015

We report on a specific procedure in the correlation plane which allows us to make more robust and discriminating decision for face recognition applications. In this scheme, we multiply the correlation plane by a nonlinear function which is chosen to increase the correlation peak, reduce the autocorrelation noise, and increase the inter-correlation noise. In our work we present tests using a VanderLugt correlator (VLC) fabricated with different filters (phase-only filter (POF), composite POF) and we also discuss the efficiency of the protocol using peak-to-correlation-energy measures. Rewardingly, our technical results demonstrate that this method is remarkably efficient to increase both robustness and discrimination performances of a VLC. © 2015 Elsevier B.V. All rights reserved.


Alfalou A.,Equipe Vision | Brosseau C.,University of Western Brittany | Abdallah N.,Equipe Vision | Abdallah N.,University of Western Brittany
Optics Communications | Year: 2015

We study theoretically a simultaneous compression and encryption method which is optically implementable and well adapted to color images. Remarkably, we also show that an optimized version of this method can be used to process images from video sequences which are treated as multiple images with taking care of temporal redundancy. The major strength of the method is in its generality and robustness against various known-plaintext attacks making this algorithm appealing for color video images. © 2014 Elsevier B.V.


Elbouz M.,Equipe Vision | Alfalou A.,Equipe Vision | Brosseau C.,University of Western Brittany | Ben Haj Yahia N.,Equipe Vision | Alam M.S.,University of South Alabama
Optics Communications | Year: 2015

We present an optimized system specially designed for the tracking and recognition of moving subjects in a confined environment (such as an elderly remaining at home). In the first step of our study, we use a VanderLugt correlator (VLC) with an adapted pre-processing treatment of the input plane and a postprocessing of the correlation plane via a nonlinear function allowing us to make a robust decision. The second step is based on an optical joint transform correlation (JTC)-based system (NZ-NL-correlation JTC) for achieving improved detection and tracking of moving persons in a confined space. The proposed system has been found to have significantly superior discrimination and robustness capabilities allowing to detect an unknown target in an input scene and to determine the target's trajectory when this target is in motion. This system offers robust tracking performance of a moving target in several scenarios, such as rotational variation of input faces. Test results obtained using various real life video sequences show that the proposed system is particularly suitable for real-time detection and tracking of moving objects. © 2015 Elsevier B.V. All rights reserved.


Ouerhani Y.,Actris Brest | Desthieux M.,Actris Brest | Alfalou A.,Equipe Vision
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

In this paper, we propose and validate a new system used to explore road assets. In this work we are interested on the vertical road signs. To do this, we are based on the combination of road signs detection, recognition and identification using data provides by sensors. The proposed approach consists on using panoramic views provided by the innovative device, VIAPIX®1, developed by our company ACTRIS2. We are based also on the optimized correlation technique for road signs recognition and identification on pictures. Obtained results shows the interest on using panoramic views compared to results obtained using images provided using only one camera. © 2015 SPIE.

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