No abstract

In this study, the authors will show that coding the positions of the symbols, instead of their values, can be a good way to implement efficient Slepian–Wolf (SW) coding and can reduce the complexity of both the encoder and the decoder. The authors will also propose a practical distributed video coding (DVC) system that exploits this idea. This system will use binary maps to indicate the positions of the most probable symbols, instead of separating them into bitplanes. Simulations show that this position‐based SW coding allows a simple and more efficient DVC system with improved rate‐distortion performance, compared to the bitplane‐based DVC system that uses the same side information. The memory requirements at the encoder are reduced by about 50% and the number of channel coding operations is also reduced. This DVC system also allows to use an easy way to control quantisation, reduces the decoding latency, and allows fast parallel decoding.

No abstract

The hybrid Wyner-Ziv (WZ) and intra video coding system has many interesting features, like the possibility to perform real motion estimation, at the decoder, and low latency coding. In this letter, we present an improved system and we will generalize it to include the other types of WZ coding. Thus, we propose a new quantization and a new cyclic redundancy check checking technique and, most importantly, we propose many new coding modes to produce a more efficient system that exploits the strong features of each type. The resulting system can thus produce many types of hybrid frames and allows mode adaptive coding. The simulation results show an improvement of the ratedistortion efficiency and can largely outperform those of state of the art.

Abstract. Image Segmentation plays a key role in automatic weld defect detection and classification in radiographic testing. Among the segmentation methods, boundary extraction based on deformable models is a powerful technique to describe the shape and then deduce after the analysis stage, the type of the defect under investigation. This paper describes a method for automatic estimation of the contours of weld defect in radiographic images. The method uses a statistical formulation of contour estimation by exploiting statistical pressure snake based on non-parametric modeling of the image. Here the edge energy is replaced by a region energy which is a function of statistical characteristics of area of interest.