Reconstruction filter

The flow resistance behavior of the reconstructed medium can now be examined by performing 3D flow simulations with the Lattice Boltzmann method (Chen and Doolen, 1998), and obtaining the permeability of the material (Konstandopoulos, 2003). Figure 8(a) depicts a visualization of 3D flow tubes and flow velocity distributions at different cross sections in a reconstructed filter material. Figure 8(b) shows the comparison of computer simulated and experimental permeabilities obtained with the experimental protocol described in Konstandopoulos (2003). 

Fig. 8. (a) Velocity fields at different sections through the reconstructed filter wall (gray denotes the solid material, violet denotes lowest and red denotes highest velocity) and visualization of flow paths in the reconstructed filter wall and (b) comparison of experimental and simulated filter permeabilities (see Plate 8 in Color Plate Section at the end of this book). 

Perfect reconstmction filter banks allow the lossless reconstmction of the input signal in an analysis-synthesis system without quantization. While not a necessary feature, the use of a perfect reconstruction filter bank simplifies the design of a coding system, While at some point other filter banks have been proposed for use in perceptual coders (e.g. wave digital filters, see [Sauvagerd, 1988]), all currently used filter banks are either perfect reconstmction or near perfect... 

For 3D reconstructions, use of a reconstruction filter that does not highlight the edges too much (soft tissue filter). 

For this purpose the inverse of the y-F mapping with A as a parameter must be calculated. The reconstructed transducer displacement is then obtained in a second step by fitting in the reconstructed force F into the actuator equation (6.56). The corresponding reconstruction filter equation is... 

This is done in a so-called reconstruction filter unit, compare Fig. 6.135. The measured values Am and are determined from the port quantities A and z by means of special electrical measurement circuits. Together with the driving electronics for the transducer, they form part of the measurement circuit and power electronics unit illustrated in Fig. 6.135. 

Fig. 6.137. Self-sensing solid-state actuator with linear reconstruction filter...

The reconstruction filters (kernels) are the same for all four-scan modes, leading to a uniform image appearance when different modes are combined. AU image data can be automatically or retrospectively sent to different network nodes (PCs, workstations, archives) in the conventional DICOM format the new enhanced-... 

Fig. 2 (a) Separable and (b) quincunx lattice in the spatial and fiequency domains. Dark area indicates the Voronoi ceU. In the case of perfect reconstruction filter banks based on quincunx sampling, the black area represents the sub band for the low-pass analysis filter ho(m n), whereas the gray area corresponds the shape of a high-pass filter hi(m n) to achieve the aliasing cancellation after the complete analysis/synthesis procedure... 

J. Kovacevic and M. Vetterli, Nonseparable multidimensional perfect reconstruction filter banks and wavelet bases for Rn, IEEE Trans. Inform. Theory, vol. 38, pp. 533-555, Mar. 1992. 

E. Viscito and J. P. AUebach, The analysis and design of multidimensional FIR perfect reconstruction filter banks for arbitrary sampling lattices, IEEE Trans. Circuits Syst., vol. 38, pp. 29-41, Jan. 

Projection reconstruction 2-D Projection reconstruction Filtered backprojection (FB)... 

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