William Puech

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Unlike airborne multi-echo laser scanner systems, full-waveform systems are able to digitize and record the entire backscattered signal of each laser pulse. It has been demonstrated that decomposing the return waveforms into a mixture of Gaussian components was suitable. In this paper, we focus on the improvement of peak detection and of raw signal(More)
This paper presents a novel method for the protection of bitstreams of state of the art video codec H.264/AVC. The problem of selective encryption (SE) is addressed along with the compression in the entropy coding modules. H.264/AVC supports two types of entropy coding modules. Context-adaptive variable length coding (CAVLC) is supported in H.264/AVC(More)
Since several years, the protection of multimedia data is becoming very important. The protection of this multimedia data can be done with encryption or data hiding algorithms. To decrease the transmission time, the data compression is necessary. Since few years, a new problem is trying to combine in a single step, compression, encryption and data hiding.(More)
This work presents a new method that combines image encryption and watermarking technique for safe transmission purpose. This method is based on the combination of public-private keys and secret key ciphering, and watermarking. The encryption algorithm with secret key is applied to the image. We encrypt the secret key with an encryption method based on(More)
A classic approach to obtain High Dynamic Range Images (HDRI) consists in combining multiple images of the same scene with varying exposures. However, if the scene is not static during the time of capture, moving objects will appear blurry and ghosted, i.e. in multiple locations. Detecting and removing ghosting artifacts is an important issue for automatic(More)
Several methods have been proposed to reconstruct a High Dynamic Range (HDR) image from differently exposed photographs that are either scanned films or firmware-processed outputs of digital cameras [Debevec et al, 1997]. We use instead the unprocessed sensor data of digital cameras and show how this simplifies the HDR image reconstruction and more(More)
In this paper, we present a novel approach for active finger-printing of state of the art video codec H.264/AVC. Tardos probabilistic fingerprinting code is embedded in H.264/AVC video signals using spread spectrum watermarking technique. Different linear and non-linear collusion attacks have been performed in the pixel domain to show the robustness of the(More)
This paper presents a new decoder for probabilistic binary traitor tracing codes under the marking assumption. It is based on a binary hypothesis testing rule which integrates a collusion channel relaxation so as to obtain numerical and simple accusation functions. This decoder is blind as no estimation of the collusion channel prior to the accusation is(More)
This paper presents a new approach for reconstructing images mapped or painted on straight uniform generalized cylinders (SUGC). A set of monocular images is taken from di!erent viewpoints in order to be mosaiced and to represent the entire scene in detail. The expressions of the SUGC's projection axis are derived from two cross-sections projected onto the(More)