Phongs illumination model requires unit length vectors. The surface normal has to be normalized due to the linear interpolation, and if we use single point light sources or a xed view point, we have to normalize the vectors pointing to the light source and to the viewer. Unfortunately, normalization is a relatively costly operation. One of the main reasons for this is the square root involved. ...

We propose a unified framework for the analysis of estimators of geometrical vector quantities and vector systems through a collection of performance measures. Unlike standard performance indicators, these measures have intuitive geometrical and physical interpretations, are independent of the coordinate reference frame, and are applicable to arbitrary parameterizations of the unknown vector or...

ing from Special Machine Features In the context of this thesis all short vector SIMD extensions feature the functionality required in intermediate level building blocks. However, the implementation of such building blocks depends on special features of the target architecture. For instance, a complex reordering operation like a permutation has to be implemented using register-register permutat...

In transcoding, simply reusing the motion vectors extracted from an incoming video bit stream may not result in the best quality. In this paper, we show that the incoming motion vectors become nonoptimal due to the reconstruction errors. To achieve the best video quality possible, a new motion estimation should be performed in the transcoder. We propose a fast-search adaptive motion vector refi...

It is a well-known limitation of all commercially available scanners that only the velocity component along the propagation direction of the emitted pulse is measured, when evaluating blood velocities with ultrasound. Proposals for solving this limitation using several transducers or speckle tracking can be found in the literature, but no method with a satisfactory performance has been found th...

Porosity is considered as an important petrophysical parameter in characterizing reservoirs, calculating in-situ oil reserves, and production evaluation. Nowadays, using intelligent techniques has become a popular method for porosity estimation. Support vector machine (SVM) a new intelligent method with a great generalization potential of modeling non-linear relationships has been introduced fo...

Hierarchical Table-Lookup Vector Quantization (HVQ) is a type of structured vector quantization first described by Chang and Gray. By replacing a full search of the codebook with a recursive series of tablelookups, HVQs pay a distortion and memory requirement penalty in return for computational simplicity, and hence speed, at the encoder. Earlier work has shown that HVQs achieving the same rate...