On 09/06/2009 01:51 PM, spencerg wrote:
Thanks to Kevin Middleton, Barry Bowlingson, M. Austenfeld:
The Hedrick reference is very interesting, digitizing a video of the
flight of a moth. This shows the state of the art AND describes "freely
available MATLAB" code. I've used Matlab before, but it would strain my
budget right now to obtain it. I've translated Matlab into R before, and
I could do that again if needed. First, however, I think I want to
review the "Motion" and "OpenCV" projects -- and possibly "ImageJ".
The RImageJ R package provides some link between R and ImageJ, it is
very simple (the package has 5 lines of R code), but might help you.
See http://tr.im/qzSl for the annoucement on my blog.
I want to convert videos into functional time series, more complicated
than the "gait" data set in the "fda" package but perhaps not as
demanding as Hendrick's the flight of a moth. I want to measure dynamic
bridge deflection midspan to see how that varies between spans and
throughout a duty cycle. I will ultimately want to measure millimeters
from high resolution video if possible. For a railroad bridge, a duty
cycle will be the passing of a train, measuring both maximum deflection
and oscillations. For highway bridges, I want to be able to measure the
changes from the morning rush hour to midday to the late afternoon rush
hour -- and preferably also the mostly unloaded period between 2 and 3
AM. I might be able to place corner reflectors on the bridge to mark the
points I want to trace, though I'd prefer to be able to do it without
that. In any event, I'd like to create a functional time series. I may
also be able to get traffic counts, so I could model deflection as a
function of traffic.
Thanks again to Middleton, Bowlingson, and Austenfeld.
Best Wishes,
Spencer
Barry Rowlingson wrote:
On Sun, Sep 6, 2009 at 1:07 AM, spencerg<spencer.gra...@prodsyse.com>
wrote:
What software exists for digitizing video to quantify the motion of
specific features in the image? I might be willing to use something
that's
NOT in R, though I'd prefer something in R (or at least with an R
intereface).
The 'Motion' project seems to do quite a bit:
http://www.lavrsen.dk/foswiki/bin/view/Motion/WebHome
Specifically it will capture frames from a video device, detect
movement, and write jpeg or mpeg files when it detects movement.
You can control it via http commands (which you can send from R) or
it can start external commands on events (such as starting to detect
motion) - these commands could trigger things in R.
Motion is GPL licensed which means you can take the code and do stuff
with it - it might be possible to link R directly to the underlying
motion detection algorithms.
So what's left for R to do? Or do you want to use it to develop new
motion detection algorithms?
Barry
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