Computer-image analysis

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

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. 

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). 

Alemanskin et al. (79) extended the use of the entropic measure of mixing to both dispersive and distributive mixing using essentially modified Shannon entropy for systems with multiple species. These authors have also employed entropy to asses color homogeneity in extruded samples by means of computer image analysis and using standard direct red-blue-red (RGB) correlations (80,81). 

Certain manufacturers have begun to include control materials in test kits (e.g., Dako s HER2 kit), especially when graded interpretation (quantification) is required. These are valuable for determining levels of intensity. As described, computer image analysis methods are... 

The high reproducibility of the positions of the spots, which is very important for interpretation of protein 2-DE maps, has been particularly improved with IPGs used in the first, lEF, dimension. For qualitative and quantitative analysis and for intergel comparison the 2-DE maps are converted into digital data using densitometers, scanners, or video cameras and evaluated by computer image analysis. 

The observation of images of composites may lead to qualitative conclusions only, but it does mean that the existence of certain objects and their reciprocal relations may be confirmed. The quantitative data and their analysis is necessary for rational design of composite materials and for effective determination of the relation between the materials structures and properties. Computer image analysis has been developed over the last 20 years to enable quantitative analysis on the basis of images of any kind. Using a basically similar approach to an image as in manual or semi-automatic methods, the fully automatic approach offers much greater possibilities of quantitative determination of various parameters that characterize the structures of the materials. 

This equation is applied to the results of a computer image analysis, where plain images are analyzed. This is the case for pore systems, structures of cracks and other defects, distribution of fibres, etc. 

The spacing factor is low when the total air content is sufficiently high and single air bubbles are small and uniformly dispersed in the matrix. Pores > 5 pm are recognized on specially prepared cross-sections, then counted and recorded manually or using computer image analysis - in both cases based on ASTM C 457 (1991). The quality of the surface treatment of concrete specimens prior to the microscopic examination is decisive. 

In direct measurement methods the microscopic examination by optical or scanning electron microscopes is eventually completed by computer image analysis. Stereology formulae are used to deduce three-dimensional structure from plane images. However, the complex shapes of pores in cement paste do not facilitate the task. 

The results obtained from the indirect methods are often controversial, because actually it is not a pore system that is examined but rather the processes applied in these methods the results reflect only the pore size distribution response. Any established value of pore diameter has only conventional meaning and may be different than diameters obtained from other methods. The indirect methods more or less influence the object of observation and measurements because the interventions disrupt material structure. Determining of distribution of pore diameters in cement paste is performed by the mercury porosimetry method and the results are partly confirmed by observations and counting the pores by computer image analysis, but mercury intrusion may damage and alter the material microstructure. Furthermore, the intrusion of mercury into a pore is related to the orifice of the pore rather than to its real dimension (Diamond 2000). Other methods, like capillary condensation, give considerably different values. 

The recognition and identification of cracks and microcracks with appropriate accuracy is necessary for their quantitative description. Thanks to recent technical tools and computer methods the acquisition of data and their processing is considerably developed in view to obtain reliable quantitative information. Certain methods used in the past are not described here, but modern processes in which computer image analysis plays a significant role are described. The review of various traditional methods may be found in the paper by Hornain et al. (1996). 

Extensive application of computer image analysis to varions kinds of images obtained by different methods has led to quantitative resnlts in several tests where, until last year, mostly qualitative conclusions were available. 

Test methods Standardization of test methods Relation between properties of specimens and of a material in a structure Testing of structures in natural scale Accelerated test methods and evaluation of durability New test methods computer image analysis, tomography, micro-indentation, etc. 

Figure 12.1 Micromanipulation system consisting of a micropipette chamber mounted on an inverted phase-contrast microscope equipped with a sensitive CCD camera (A), real-time image analysis running on a UNIX workstation (B), and a set-up controlling pressure and manipulator position by a personal computer (C). The pipette suction pressure is created hydrostatically. We can generate controlled membrane tensions down to 10 dyncm corresponding to 1 pm height difference between two linked water reservoirs. The micropipettes are mounted on two three-axis manipulators which can be moved manually or by computer. Image analysis is integrated with the automated experimental device control.

Other techniques are of interest but will not be covered here. For example, emphasis is put on the pros and cons of the pendant drop technique by Ambwani and Fort [63]. The pendant drop method has been very laborious traditionally. A fas standard instrumentation using computer image analysis has been described by Hansen and Rodsrud [64]. The characterization of monolayers can be carried out by this technique. For example, Li et al. described the required equipment and the application of the pendant drop technique to measure the surface tension of a insoluble monolayer covered onto a water drop surface [65]. 

Caldwell, D. E., Korber, D. R., and Lawrence, J. R., Confocal Laser Microscopy and Computer Image Analysis in Microbial Ecology, in Marshall, K. C. (eA.), Advances in Microbial Ecology, vol. 12, New York, Plemun Press, 1992. 

A great variety of experimental techniques has been developed to measure film thickness in EHL contacts. Optical interferometry is the most commonly used technique and has significantly contributed to a better understanding of the way an EHL contact works [9]. The recently developed colorimetric interferometry techniques that combine optical interferometry and computer image analysis allow the mapping of film thickness distributions... 

The 2D LSCM slices were binarized with the aid of computer image analysis and were stuck together to make a 3D representation of the structures (see Sect. 3.1). The MCA was used to model the interface between the DPB and PB components by contiguous polygons in the reconstruction process. The interfacial area was estimated by summing the area of the polygons, from which the interfacial area per unit volume, S(f)> was estimated. The volume fraction of one of the phases, 0, was also measured. The volume... 

---