Posted by
Ed Simmons on
Oct 16, 2013; 4:13pm
URL: http://imagej.273.s1.nabble.com/Help-measure-and-compare-activity-in-a-video-quantifiably-tp5005205p5005215.html
Hi Leila,
On 16/10/2013 17:53, LailaHiggins wrote:
> I have videos of starfish walking on a glass surface, filmed from underneath,
> 8 bit grey-scale. I am trying to study the movement of the tube feet, and I
> need advice (help!) on how to proceed.
> Would it be possible to compare the difference in activeness of tube feet in
> one region of the video with another region? Ideally I’d like to make a
> relative scale of activity so that I can compare, but I don’t know how to
> measure it in a quantifiable way.
If you compute the difference between each frame and the next in the
stack, you will obtain data about which pixels have changed. You could
then blur this motion map image stack to get areas of activity, these
are then easy to quantify in some way...
>
> I have performed a stack registration (using the plugin StackReg), so that
> the frames are aligned to keep the starfish stationary.
This should help your cause if all you are interested is the relative
activity in different areas under your starfish.
> A brief description of the animal:
> The starfish are spiny and have five rays (arms). On the underside of the
> rays are the tube feet, the locomotory organs of the starfish. Tube feet
> are small, cylindrical, extensible appendages on the underside of the
> starfish terminating in a flattened disc, typically 1 mm in diameter. One
> starfish has hundreds of tube feet. It is important to note that the tube
> feet in general are the same colour as the starfish, and therefore present
> very little contrast. Also a whole starfish does not fit in the field of
> view, and as the sequence progresses, it walks out of the field of view.
> I really appreciate any ideas you might have on how I’d go about this,
> Kind regards,
> Laila.
>
>
>
It shouldn't be too hard to make a simple macro to test this out. Start
simple, and see if yuo can generate a motion map image stack, this in
itself will show you a lot just by looking at the images that are produced.
Hope that helps,
Ed
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Ed Simmons
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www.esimagingsolutions.com
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