[Image-SIG] Fw: Python - WEIRD Code needed (help with)

Ior Bock lab_monkey at mail2world.com
Sat Dec 23 07:15:25 CET 2006

<-----Original Message----->

From: Ior Bock [lab_monkey at mail2world.com]
Sent: 12/19/2006 5:55:38 PM
To: help at python.org
Subject: Python - WEIRD Code needed (help with)


Looking for help with trying to figure out a way to emulate simple tv
video feedback with PYTHON using simple scripts.

Am presenting this to students and hope to stimulate their interest in
this phenomenon.

I've a background in Visual Basic, and am using an old version, 4.0, it
compiles to a smaller executable which I prefer. I find myself in an odd
situation, needing a very simple yet powerful capability of Python for a
VB app Im working on.

For this scenario I don't know where to begin though, am hoping for some
thoughtful input, suggestions, and code samples to get me started would
be a God send. Would prefer NOT using DirectX if possible.

I know VERY litle about Python and a fair bit about VB.

Have included a bunch of links to illustrate what I am looking for.
Really what Im after is best represented in the very first link, and
this is what I would like to replicate.

Would like to do this with integers being used as the feedback medium,
so instead of video signal feedback, we use "number feedback"

Imagine in the following brief description we have our numbers acting as
the signal in and signal out;

"Video Feedback is easy and fun for anyone with a video camera and a
monitor (TV screen). To make the simplest kind, take the "video out"
from the camera and plug it into the "video in" on the monitor, and then
point the camera at the monitor, so the monitor displays a picture of
the monitor. Now you have a video feedback loop! To get the effects
demonstrated in the gallery, careful adjustments of the various knobs
and dials on the camera and monitor are required. I also recommended
that you get a tripod. This is especially useful for doing rotations,
since the camera can be held at a fixed angle. Adjust the tripod so you
can rotate the camera about the viewing axis."

Have tried this in Visual Basic, so in the VB code, user inputs numbers
into some text boxes and these serve as the "video in" and "video out"
mechanisms, so through looped recursion;

do while loop_counter <> 5000
textbox1.text = 100 represents Camera video out
textbox2.text = 75 represents Monitor video in
var = new value + (textbox1.text + textbox2.text) recursion value
(code here generates graphic spiral )

Would like the feedback generated however to be tied directly to the
number inputs specifically though. 

P.S. - got the following response from a VB forum;

"Originally Posted by chemicalNova
In any way in VB, drawing the graphical spiral will be very very VERY

Does it have to be literally the same as whats above? How about, for
example, a PictureBox that acts as the screen (video out), and a
PictureBox that acts as the camera (video in). The Screen picturebox has
a mini version of the camera box, which holds the contents of the Screen
Picturebox. Then, you could possibly give exact rotation angles, for the
camera, and display it inside the screen picturebox."


Ideally, I'd love to be able to simply have some extremely small
executable that just accepts inputs
does the calculations above and then spits out the graphical outputs. 

If I could simply have my VB app, 'call' the name of the tiny Python
executable, and then the Python executable
just automatically looked for a named text file (created by the VB app)
and extracted number file from this, then performed the calcs, then
displayes the feedback emulation
that would be ideal!

Following demonstrates what Im after exactly, note I'm not looking for a
solution that needs to be really high fine complex graphics, etc - just
want to demonstrate the basic concept. 






Space-Time Dynamics in Video Feedback James P. Crutchfield Video
feedback provides a readily available experimental system to study
complex spatial and temporal dynamics. This article outlines the use and
modeling of video feedback systems. It 


MediaSculp - Gallery 

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