If it’s not a joke, than what can I say - it’s an interesting observation (but for what?)

http://arxiv.org/abs/physics/0606246

You must see it:

Physics, abstract
physics/0606246

From: Jose-Luis Aragon [view email]Date: Wed, 28 Jun 2006 14:10:58 GMT   (167kb)

Kolmogorov scaling in impassioned van Gogh paintings

Authors:
J.L. Aragón,
Gerardo G. Naumis,
M. Bai,
M. Torres,
P.K. Maini

Comments: 3 pages, 6 figures

Subj-class: Fluid Dynamics

We show that some impassioned van Gogh paintings display scaling properties
similar to the observed in turbulent fluids, suggesting that these paintings
reflect the fingerprint of turbulence with such a realism that is even
consistent with the way that a mathematical model characterizes this
phenomenon. Specifically, we show that the probability distribution function
(PDF) of luminance fluctuations of points (pixels) separated by a distance R is
consistent with the Kolmogorov scaling theory in turbulent fluids. We also show
that the most turbulent paintings of van Gogh coincide with periods of
prolonged psychotic agitation of this artist.

The conjunction is like this: if you see eddies in this beautiful picture from NASA

Then you may start doing all kind of PDF analysis of everything and find out maybe that van Gogh’s paintings, e.g. The Starry Night is also “turbulent”, isn’t it nice?

http://www.moma.org/collection/printable_view.php?object_id=79802

URAPIV for cars?

The researchers from the International Automotive Research Centre at the Warwick University has asked if URAPIV can perform on the images like the example above. The original images are typical gray scale images, but taken with a camera that also moves. Therefore, the motion is a superposition of the motion of cars (note the direction of the middle jeep) and of the "optical flow" because of the camera shift. Anyhow, it was an interesting challenge and we were happy with the preliminary result. For this purpose we also updated URAPIV with a version for Matlab R14SP2 (R14 is ver 7) that reads TIFF, JPG, BMP or all other formats that IMREAD function of Matlab can read. The names are like from a high-speed camera (sometimes called time resolved PIV or high frame rate PIV, etc.) and we analyze 1st with the 2nd, 2nd with the 3rd, and so on.

The strange image is an overlay of the two images in one RGB image, when the first one is the red layer (R) and the second image is the blue layer (B). Arrows are green, respectively. The magenta is all the regions that didn't change and the differences are seen between the images where the color is blue or red. In Matlab we do it like this:

>> imshow(cat(3,a,a*0,b)); % a/b are the first/second image  

Don't hesitate to ask for the most recent version by e-mail, we are always glad to see URAPIV that helps to resolve different problems.

PIV analysis software in Pascal

AnaPIV is a free, open-source software for PIV analysis of PCX images, written by Holger Nobach.

AnaPIV calculates two-dimensional vector fields from PIV images.
The program implements

• iterative vector field correction
• window sub-pixel shift and deformation
• interrogation area weighting

The program is available pre-compiled for Mac OS X PowerPC or as a 32
bit application for Windows including its source code in Pascal.

Very nice feedback from the URAPIV users in Spain

We received the following e-mail that we appreciate a lot:

This is the last work with PIV. The work was presented
in a congress, in Milan.

Now, we continue with this inventigation. …

Good luck for PyPIV!

Jose Manuel Pedrero

The paper is entitled:
EXPERIMENTAL INVESTIGATION OF FLOW PATTERN IN ENHANCED HEAT EXCHANGERS WITH ACTIVE INSERT DEVICES
by
J. P. Solano*, A. García*, J. M. Pedrero**, P. G. Vicente**, A. Viedma*,
*Departamento de Ingeniería Térmica y de Fluidos, Universidad Politécnica de Cartagena. Campus de la Muralla del Mar, 30202 Cartagena, Spain.
Tel: +34 968 32 5938, Fax: +34 968 32 5999, e-mail address: juanp.solano@upct
**Departamento de Ingeniería de Sistemas Industriales, Universidad Miguel Hernández.. Avenida del Ferrocarril, s/n, 03202 Elche, Spain.

You can get a copy directly from the authors or send us an e-mail and we’ll forward the request.