William Puech - Academia.edu (original) (raw)

IJCSIS Volumes by William Puech

International Journal of Computer Science and Information Security (IJCSIS) provides a major venu... more International Journal of Computer Science and Information Security (IJCSIS) provides a major venue for rapid publication of high quality computer science research, including multimedia, information science, security, mobile & wireless network, data mining, software engineering and emerging technologies etc. IJCSIS has continued to make progress and has attracted the attention of researchers worldwide, as indicated by the increasing number of both submissions and published papers, and also from the web statistics.. It is included in major Indexing and Abstracting services.

https://sites.google.com/site/ijcsis/Home

Papers by William Puech

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci-entific ... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et a ̀ la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Watermarking in the Joint Photographic Experts Group (JPEG)2000 coding pipeline is investigated i... more Watermarking in the Joint Photographic Experts Group (JPEG)2000 coding pipeline is investigated in this paper. A joint quantization and watermarking method based on trellis-coded quantization (TCQ) is proposed to reliably embed data during the quantization stage of the JPEG2000 part 2 codec. The central contribution of this work is the use of a single quantization module to jointly perform quantization and watermark embedding at the same time. The TCQbased watermarking technique allows embedding the watermark in the detail sub-bands of one or more resolution levels except the first one. Watermark recovery is performed after image decompression. The performance of this joint scheme in terms of image quality and robustness against common image attacks was estimated on real images.

IEEE Access, 2021

Automated image analysis and deep learning tools such as object detection models are being used i... more Automated image analysis and deep learning tools such as object detection models are being used increasingly by biologists. However, biological datasets often have constraints that are challenging for the use of deep learning. Classes are often imbalanced, similar, or too few for robust learning. In this paper we present a robust method relying on hierarchical classification to perform very small object detection. We illustrate our results on a custom dataset featuring 22 classes of arthropods used to study biodiversity. This dataset shows several constraints that are frequent when using deep learning on biological data with a high class imbalance, some classes learned on only a few training examples and a high similarity between classes. We propose to first perform detection at a super-class level, before performing a detailed classification at a class level. We compare the obtained results with our proposed method to a global detector, trained without hierarchical classification. Our method succeeds in obtaining a mAP of 75 %, while the global detector only achieves a mAP of 48 %. Moreover, our method shows high precision even on classes with the less train examples. Confusions between classes with our method are fewer and are of a lesser impact. We are able achieve a more robust object classification with the use of our proposed method. This method can also enable better control on the model's output which can be particularly valuable when handling ecological, biological or medical data for example.

Ce manuscrit est structuré en deux parties autour de l'état de l'art (chapitres 2 à 4) et des con... more Ce manuscrit est structuré en deux parties autour de l'état de l'art (chapitres 2 à 4) et des contributions (chapitres 5 à 7). Le chapitre 2 expose les différentes notions de base nécessaires à la compréhension de ces travaux. Nous allons introduire différents concepts autour de la modélisation 3D et les traitements relatifs à ce type de données. Dans le chapitre 3, nous présentons différentes méthodes de visualisation de données, notamment la problématique relative aux bâtiments et les méthodes de visualisation de données hétérogènes. Dans le chapitre 4, nous introduisons la problématique de la gestion de données, ainsi que les méthodes de visualisation interactive et multi-vues. Le chapitre 5 présente le modèle que nous avons mis en place au travers d'une architecture client / serveur. Nous présentons également les solutions de modélisation autour des capteurs du bâtiment. Le chapitre 6 décrit les différentes visualisations mises en place dans le cadre de ces travaux : les visualisations 2D, les visualisations 3D multi-résolution et l'outil de fouille de données. Enfin le chapitre 7 présente les différents résultats que nous avons obtenus au travers de deux jeux de données réelles. Dans le chapitre 8, nous clôturons ce manuscrit en présentant une conclusion générale à ces travaux ainsi que les différentes perspectives envisagées.

IEEE Transactions on Circuits and Systems for Video Technology, 2021

During the last few decades, the transmission of images over secure networks has exponentially gr... more During the last few decades, the transmission of images over secure networks has exponentially grown. Data security in certain applications such as secure storage, authentication or privacy protection on cloud platforms, require specific strategies for multimedia. Cryptography can be used for this purpose. Indeed, using a secret key, it is possible to make data unreadable in order to secure it. Although encryption approaches are effective to make the original data unreadable, they are also very sensitive to noise. Because of the introduction of noise into an encrypted image during its transmission or storage, the original data cannot be recovered. In this paper, we first describe a new encryption mode called CFB-then-ECB and based on a combination of the CFB mode and the ECB mode for AES encryption. Using this new encryption mode, if one encrypted pixel block is noised, this will result in two incorrectly reconstructed pixel blocks during the decryption (the current and the following pixel blocks). This noise spreading is then exploited in a new proposed approach of noisy encrypted image correction. It contains two main steps involving a classifier to discriminate clear and encrypted pixel blocks. After a direct decryption of a noisy encrypted image, the first step is to identify and localize the pixel blocks that are probably incorrectly decrypted. The second step of our proposed approach is to analyze and correct these pixel blocks. Experimental results show that the proposed method can be used to blindly correct noisy encrypted images, while preserving the image structure without increasing the original data size with additional information.

Frontiers in Signal Processing

Copy-move forgery detection is a challenging task in digital image forensics. Keypoint-based dete... more Copy-move forgery detection is a challenging task in digital image forensics. Keypoint-based detection methods have proven to be very efficient to detect copied-moved forged areas in images. Although these methods are effective, the keypoint matching phase has a high complexity, which takes a long time to detect forgeries, especially for very large images such as 4K Ultra HD images. In this paper, we propose a new keypoint-based method with a new fast feature matching algorithm, based on the generalized two nearest-neighbor (g2NN) algorithm allowing us to greatly reduce the complexity and thus the computation time. First, we extract keypoints from the input image. After ordering them, we perform a match search restricted to a window around the current keypoint. To detect the keypoints, we propose not to use a threshold, which allows low intensity keypoint matching and a very efficient detection of copy-move forgery, even in very uniform or weakly textured areas. Then, we apply a new...

Applied Sciences, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

The data-hiding is an application of the steganography. Its purpose is to embed a large amount of... more The data-hiding is an application of the steganography. Its purpose is to embed a large amount of data in images in an invisible way. Several methods are robust to the JPEG compression algorithm. In the present paper, we investigate the noise they induce on images and propose an improvement to make it minimal with regard to the transparency.

2016 Sixth International Conference on Image Processing Theory, Tools and Applications (IPTA), 2016

2015 23rd European Signal Processing Conference (EUSIPCO), 2015

CT-Scanner devices produce three-dimensional images of the internal structure of the body. In thi... more CT-Scanner devices produce three-dimensional images of the internal structure of the body. In this paper, we propose a method that is based on the analysis of sensor noise to identify the CT-Scanner device. For each CT-scanner we built a reference pattern noise and a correlation map from its slices. Finally, we can correlate any test slice with the reference pattern noise of each device according to its correlation map. This correlation map gives a weighting for each pixel regarding its position in the reference pattern noise. We used a waveletbased Wiener filter and an edge detection method to extract the noise from a slice. Experiments were applied on three CT-Scanners with 40 3D images, including 3600 slices, and we demonstrate that we are able to identify each CT-Scanner separately.

Computer-Aided Design, 2015

and key words The traffic of digital images has increased rapidly in the wide networks. The prote... more and key words The traffic of digital images has increased rapidly in the wide networks. The protection of this kind of data becomes important for many reasons such as confidentiality, obscurity and security. Nowadays, the most important engine to provide confidentiality is encryption. Therefore, the classical and modern ciphers are not suitable for such huge quantity of data in real-time environment. Selective encryption (SE) is an approach to encode a portion of the data in order to reduce computational requirements and to provide a proportional privacy. This paper presents a new method of partial or selective encryption for JPEG images. It is based on encoding of some Huffman bitstream with AES cipher. The proposed method results in a significant reduction in encrypting and decrypting processing time, provides a constant bit rate and keeps the JPEG bitstream compliance.

IEEE Transactions on Information Forensics and Security, 2018

Reversible data hiding in encrypted images (RDHEI) is an effective technique to embed data in the... more Reversible data hiding in encrypted images (RDHEI) is an effective technique to embed data in the encrypted domain. An original image is encrypted with a secret key and during or after its transmission, it is possible to embed additional information in the encrypted image, without knowing the encryption key or the original content of the image. During the decoding process, the secret message can be extracted and the original image can be reconstructed. In the last few years, RDHEI has started to draw research interest. Indeed, with the development of cloud computing, data privacy has become a real issue. However, none of the existing methods allows us to hide a large amount of information in a reversible manner. In this paper, we propose a new reversible method based on MSB (most significant bit) prediction with a very high capacity. We present two approaches, these are: high capacity reversible data hiding approach with correction of prediction errors (CPE-HCRDH) and high capacity reversible data hiding approach with embedded prediction errors (EPE-HCRDH). With this method, regardless of the approach used, our results are better than those obtained with current state of the art methods, both in terms of reconstructed image quality and embedding capacity.

Publication in the conference proceedings of EUSIPCO, Tampere, Finland, 2000

2018 Eighth International Conference on Image Processing Theory, Tools and Applications (IPTA)

JPEG is the most used image compression algorithm but block wise DCT compression methods produce ... more JPEG is the most used image compression algorithm but block wise DCT compression methods produce artifacts due to coefficient quantization. JPEG decompression can be seen as a reconstruction problem constrained by quantization. In this context, we propose to handle this problem by using intervalvalued arithmetic. Our method allows to produce interval-valued image that includes the non-compressed original image. The produced convex set allows to apply constrained Total Variation (TV) reconstruction in order to reduce JPEG artifacts (blocking, grainy effects and high frequency noise). Experiments show visual improvement of JPEG decoding assessed by non-reference quality metric. In addition, the stopping criterion of the TV algorithm is given by this metric which provides evidence about JPEG decompression improvement.