🚀 go-pugleaf

In article 24902@Princeton.EDU, weisberg@phoenix.Princeton.EDU (Arel Y.
Weisberg) writes:  
>I'm working with VHS video of a complex water flow seeded with particles 
>and I'm trying to track the particles' paths.  >

I know of several people working in this field using a variety of
techniques. It would help to know if you want the whole filed or just a
single plane. I assume you are going for the plane.

>Are there any "classic" texts or articles on this problem? Most of what 
>I've done so far has been image ehancement to remove all the background 
>noise, so n


I know of several ways to obtain the veocity vectors, it depsends on
the seeding density which technique will be appropriate (fast and
accurate).

Particle tracking - essentially low seeding density.  Particle image
velocimetry - medium seeding density Speckle velocimetry - high seeding
density

The second two involve calculating the auto/cross-correlation for small
areas of your images.

I don't know of any texts, I'll leave that for somebody else :-).
Classic articles (all three):


Adrian, RJ, Int. J. of Heat and Fluid Flow, 2, 127-145, 1986 Adrian,
RJ, Annual Review of Fluid Mechanics, 23, 261-304, 1991


Selected Articles:

Khalighi, Appl. Opt., 28(20), 4328-4332, 1989 Racca et al, Experiments
in Fluid, 6(1), 25-32, 1988 Jimenez, J. Fluid Mech, 185, 447-468, 1987
Utami, Exp. Fluids, 10, 213-223, 1991

There are many others. To get an idea of what is happening at the
moment I suggest that you get hold of the precedings for:

(1) The Sixth International Symposium on applications of laser
techniques to fluid mechanics., July 20-23, Lisbon, 1992.

(2) Optical methods and data processing in heat and fluid flow, 2-3
April, 1992, City University, London, 1992.(pub: Institute of
Mechanical Engineers, London).

(3) The proceedings from Uromch Colloquium 279, 2-5  July, 1991, TU
Delft, which will appear sometime soon (:-)) as an edition of Applied
scientific Research.

Some folk working in similar fields (taken from the above) are:

Lourenco, L , U. Florida??  
Stuart Dalziel, Applied Maths Cambridge,
England Heyes AL, U. Manchester, England


I hope this is of some help, it may well be limited as I tend to
concentrate on the last two methods and only pick up particle tracking
stuff as an aside. It seems to boil down to find a possible direction,
check the particle is somewhere close in following frames *or* find a
particle map the particles nearest to it and find the closest
representation to this in the next frame. This is a rather glib
simplification ;->

		Andy
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Andrew Hind, Dpt. Chem. Eng.           /| /|  Tel:   +44 031 650 8558 
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