54 research outputs found
Information fusion based techniques for HEVC
Aiming at the conflict circumstances of multi-parameter H.265/HEVC encoder system, the present paper introduces the analysis of many optimizations\u27 set in order to improve the trade-off between quality, performance and power consumption for different reliable and accurate applications. This method is based on the Pareto optimization and has been tested with different resolutions on real-time encoders
Pre-processing techniques to improve HEVC subjective quality
Nowadays, HEVC is the cutting edge encoding standard being the most efficient solution for transmission of video content. In this paper a subjective quality improvement based on pre-processing algorithms for homogeneous and chaotic regions detection is proposed and evaluated for low bit-rate applications at high resolutions. This goal is achieved by means of a texture classification applied to the input frames. Furthermore, these calculations help also reduce the complexity of the HEVC encoder. Therefore both the subjective quality and the HEVC performance are improved
Non-commutative Geometry and Kinetic Theory of Open Systems
The basic mathematical assumptions for autonomous linear kinetic equations
for a classical system are formulated, leading to the conclusion that if they
are differential equations on its phase space , they are at most of the 2nd
order. For open systems interacting with a bath at canonical equilibrium they
have a particular form of an equation of a generalized Fokker-Planck type. We
show that it is possible to obtain them as Liouville equations of Hamiltonian
dynamics on with a particular non-commutative differential structure,
provided certain geometric in character, conditions are fulfilled. To this end,
symplectic geometry on is developped in this context, and an outline of the
required tensor analysis and differential geometry is given. Certain questions
for the possible mathematical interpretation of this structure are also
discussed.Comment: 22 pages, LaTe
Dissipative Properties of Quantum Systems
We consider the dissipative properties of large quantum systems from the point of view of kinetic theory. The existence of a nontrivial collision operator imposes restrictions on the possible collisional invariants of the system. We consider a model in which a discrete level is coupled to a set of quantum states and which, in the limit of a large “volume,” becomes the Friedrichs model. Because of its simplicity this model allows a direct calculation of the collision operator as well as of related operators and the constants of the motion. For a degenerate spectrum the calculations become more involved but the conclusions remain simple. The special role played by the invariants that are functions of the Hamiltonion is shown to be a direct consequence of the existence of a nonvanishing collision operator. For a class of observables we obtain ergodic behavior, and this reformulation of the ergodic problem may be used in statistical mechanics to study the ergodicity of large quantum systems containing a small physical parameter such as the coupling constant or the concentration
Two low cost algorithms for improved diagonal edge detection in JPEG-LS
JPEG-LS is the latest lossless and near lossless image compression standard introduced by the Joint Photographic Experts Group (JPEG) in 1999. In this standard simple localized edge detection techniques are used in order to determine the predictive value of each pixel. These edge detection techniques only detect horizontal and vertical edges and the corresponding predictors have only been optimized for the accurate prediction of pixels in the locality of horizontal and/or vertical edges. As a result JPEG-LS produces large prediction errors in the locality of diagonal edges. We present two low cost algorithms for the detection and prediction of diagonal edge pixels in JPEG-LS. Experimental results show that the proposed schemes aid in the reduction of predictive mean squared error of up to 2-3 percent as compared to the standard
On the derivation of linear irreversible thermodynamics for classical fluids
We consider the microscopic derivation of the linearized hydrodynamic equations for an arbitrary simple fluid. Our discussion is based on the concept of hydrodynamical modes, and use is made of the ideas and methods of the theory of subdynamics. We also show that this analysis leads to the Gibbs relation for the entropy of the system
Shape adaptive padding for MPEG-4
In MPEG-4, the boundary blocks of reference video objects are padded by replicating the boundary samples towards the exterior. This scheme does not make use of the trend of pixel value variation often present near object boundaries in padding the exterior pixels of the reference video object. Rather, it results in a break of this trend at the video object boundary, resulting in higher prediction errors for those pixel locations that are within the shape of the current block, but are outside that of the predicted block. In this paper, we propose a novel shape distortion adaptive hybrid padding technique to minimise prediction errors and improve compression efficiency. We show that this technique results in boundary block coding gains of up to 9% as compared to that of the MPEG-4 scheme
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