Computer imaging

The use of experimental X-ray vidicons, original technique of X-raying and computer image processing allowed to improve basic parameters of XTVI and to achieve higher defectoscopic sensitivity and greater thickness of X-rayed materials and products. 

FIG. 1 Freeze-etching image of a bacterial cell of (a) Desulfotomaculum nigrificans (bar, 100 nm). Atomic force micrographs of the S-layer proteins of (b) Bacillus sphaericus CCM 2177 and (c) Bacillus stearothermophilus PV72/p2 recrystallized in monolayers on silicon wafers. Bars, 50 nm. The insets in (b) and (c) show the corresponding computer-image reconstructions. 

Coupling one of these cations with one of these anions gives an ionic molecule that has high electron density at the anionic end. The computer image at top right shows this for butyl methyl imidazolium hexafluorophosphate. 

The compact can either be saturated with the fluid for static measurements or dynamic measurements may be made through a computer imaging goniometer which takes successive images of the drop profile. 

Figure 6. High-resolution micrograph together with corresponding scalar structural drawing, computed image, and appropriate diffraction pattern showing structural resolution of BigWgOg with some Bi2W3012 intergrowths (24).

Crystal structures are best viewed as three-dimensional computer images that can be rotated and viewed from any direction. Crystal structures can be displayed, and downloadable programs for graphical presentation of crystal structures can be found at the EPSRC s Chemical Database Service at Daresbury. This can be accessed at http //cds.dl.ac.uk/ cds. See also ... 

Fig. 5. HRTEM image of MAPO-36 showing well-defined large apertures. The inset shows the computed image where the outline of the 12-rings is clearly visible (top and bottom are with and without taking beam damage into account) (5,43).

Troy Heany of the Molex, Inc., positions an electroplated specimen in the x-ray diffractometer (left) and then observes the computer image of the location on the specimen where the thickness is measured (right). 

Using computer imaging analysis (TopoMetrix SPMLab 3.06.06) [36], profile data for each dendrimer molecule was obtained as shown in Figure 12.16. 

Advances in pulsed lasers, microscopy and computer imaging, and the development of labelling techniques in which the donor and acceptor fluorophores become part of the biomolecules themselves have enabled the visualisation of dynamic protein interactions within living cells. 

In research conducted at the University of Groningen (Netherlands) over a 14-year period, scientists succeeded in developing a pure crystal of the cholera toxin. Over 25,000 diffraction measurements of pure crystals, it became possible to generate a computer image of the cholera toxin. It lias been observed that all bacterial toxins act in the same manner—one component is an enzyme that performs the invasive function and another component performs destruction once it enters the cell. 

Fox, S. B., Leek, R. D., Weekes, M. P., Whitehouse, R. M., Gatter, K. C., and Harris, A. L. 1995. Quantitation and prognostic value of breast cancer angiogenesis Comparison of microvessel density, chalkley count and computer image analysis. J. Pathol. 777 275-283. 

Some authors also take the approach to compute images that look as if they were taken under some canonical illuminant (e.g. Forsyth (1992)). In general, it is important that the output computed by a color constancy algorithm is not affected by changes of the illuminant. In other words, the computed descriptor should be constant irrespective of the illuminant. Otherwise, we would not have a color constancy algorithm. But at the same time, the output has to be nontrivial. If we would not make this assumption, a trivial color constancy algorithm could be found, which returns the same constant value for all input images. This was also pointed out by Forsyth (1992). 

The application of the traditional microscopic techniques is also affected by the difficulty of quantifying the structural features. Computer image analysis allows to process images in order to extract numerical data referred to the microstructure (Ding and Gunasekaran, 1998 Inoue, 1986 Kalab et al., 1995). 

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