Subspace-based and DIRECT algorithms for distorted circular contour estimation.

Circular features are commonly sought in digital image processing. The subspace-based line detection (SLIDE) method proposed to estimate the center and the radius of a single circle. In this paper, we introduce a novel method for estimating several radii while extending the circle estimation to retrieve circular-like distorted contours. Particularly, we develop and validate a new model for virtual signal generation by simulating a circular antenna. The circle center is estimated by the SLIDE method. A variable speed propagation scheme toward the circular antenna yields a linear phase signal. Therefore, a high-resolution method provides the radius. Either the gradient method or the more robust combination of dividing rectangles and spline interpolation can extend this method extend this method for free form object segmentation. The retrieval of multiple non concentric circles and rotated ellipses is also considered. To evaluate the performance of the proposed methods, we compare them with a least-squares method, Hough transform, and gradient vector flow. We apply the proposed method to hand-made images while considering some real-world images.     

Hardware implementation of a strong pseudorandom number generator based block-cipher system for color image encryption and decryption

This paper proposed a hardware architecture of a strong block-cipher system dedicated to digital image encryption and decryption. On the one hand, a pseudorandom number generator (PRNG) based on two 3D chaotic systems is created to produce strong keys. On the other hand, a robust algorithm is proposed to ensure high-level security and low computational complexity of image encryption. The algorithm performs image encryption mainly through three processes: pixel values hiding by applying the XOR operation with a key, pixel positions hiding by operating random permutation, and pixel substitution using the S-box method. To increase the complexity, R rounds of encryption could be accomplished in a loop. Then as a final step, using the Xilinx Vivado/system generator tool, the hardware cryptosystem is developed, implemented, and evaluated on an FPGA-Zynq evaluation board. According to the synthesis results, the suggested hardware system performs on a reduced FPGA area and gives a good frequency of 156.813 MHz with a high throughput of 20,072.064 Mbps. Several tools and tests utilizing various images are used to evaluate and analyze the hardware cryptosystem. The experimental results show that the hardware implementation has higher performance compared to other recent works.     

Experimental multipartner quantum communication complexity employing just one qubit

Most proposals for quantum solutions of information-theoretic problems rely on the usage of multi-partite entangled states which are still difficult to produce experimentally with current state-of-the-art technology. Here, we analyze a scheme to simplify a particular kind of multiparty communication protocols for the experiment. We prove that the fidelity of two communication complexity protocols, allowing for an N ? 1 bit communication, can be exponentially improved by N ? 1 (unentangled) qubit communication. Taking into account, for a fair comparison, all inefficiencies of state-of-the-art set-up, the experimental implementation for N = 5 outperforms the best classical protocol, making it the candidate for multi-party quantum communication applications.     

3D face verification across pose based on euler rotation and tensors

In this paper, we propose a new approach for 3D face verification based on tensor representation. Face challenges, such as illumination, expression and pose, are modeled as a multilinear algebra problem where facial images are represented as high order tensors. Particularly, to account for head pose variations, several pose scans are generated from a single depth image using Euler transformation. Multi-bloc local phase quantization (MB-LPQ) histogram features are extracted from depth face images and arranged as a third order tensor. The dimensionality of the tensor is reduced based on the higher-order singular value decomposition (HOSVD). HOSVD projects the input tensor in a new subspace in which the dimension of each tensor mode is reduced. To discriminate faces of different persons, we utilize the Enhanced Fisher Model (EFM). Experimental evaluations on CASIA-3D database, which contains large head pose variations, demonstrate the effectiveness of the proposed approach. A verification rate of 98.60% is obtained.     

Hybrid descriptor and optimized CNN with transfer learning for face recognition

Multimedia Tools and Applications - This work focuses on the development of optimized algorithms applied in the field of Face Recognition (FR). The strategy adopted represents the contribution of...