Digital image analysis profiles

A number of experimental measurement techniques are discussed, with a focus on noninvasive optical techniques such as particle image velocimetry and digital image analysis, as well as a number of academic numerical modeling tools such as discrete particle model and two-fluid model. Not only hydrodynamic aspects, such as the emergence of defluidized zones and solids circulation profile inversion, but also the effect on the bubble size distributions are discussed for wall-mounted membranes and horizontally immersed membranes. 

Figure 2.8a shows a digitized image of a drop of PDMS on a silanized silicon substrate. Manipulating such an image with a pattern analysis algorithm makes it possible to reconstruct the profile of the drop. 

An image of the particle is obtained, the profile of that image is converted to a set of x,y pairs, a process known as digitizing. The x,y set is then converted to polar coordinates, (R,0). The curve in the R,0 space is converted to a Fourier equation, the coefficients of which are extracted, and then mathematically transformed to morphic terms which themselves constitute the shape features of the particle. A sample usually consists of 100 particles, upwards of 150 profile points are extracted from each particle, giving a total of 15,000 x,y points per analysis. Once the morphic terms are obtained, the data analysis can be carried out in order to facilitate the... 

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