Re: Search for Images in a video

Posted by Straub, Volko A. (Dr.) on Dec 05, 2014; 6:47am
URL: http://imagej.273.s1.nabble.com/Search-for-Images-in-a-video-tp5010759p5010776.html

Hi Paul,

I don't know whether you solved your problem, but you could draw an ROI
on the region that changes colour and use a 'for - loop' to measure the
intensity of that area for every frame.
The macro code below will produce a list of the average grey value in
the ROI for each frame of your video in the results window:

run("Set Measurements...", "  mean redirect=None decimal=1");
for (i=1; i<nSlices+1; i++) {
     setSlice(i);
     run("Measure");
};

Hope this helps,
Volko

> Hey everyone,
>
> I need to find a way, to analyse all pictures from one video relating
> to a selected area of pixels.
>
> There is this special area of pixel(it's always at the same spot). And
> they are eiter dark(for me it seems to be black) or white.
> Most of the time this area is dark, and for me, only the sequences
> wehre the area turns white is important.
>
> How can I analyse one special area concerning the color, and then skip
> only to the pictures which have that white area.
> If there is no possibilty to skip directly, it would also be enough to
> get a list, that shows at which frame the area is white, so that I,
> myself can skip to that point.
>
> I need this for my bachelor thesis. I took films of fishes. During the
> filming I gave stimuli to the fishes, and then analyse their reaction.
> Therefor a small light diode is activetd simultan to the given
> stimulus. Thus, only this moments are relevant for me.
>
> Notice that the film is in avi and taken black/white. So the only
> coulors are "white", "black" and grey.
> I am using Ubuntu.
> There are two pictures in the appendix which show my "problem".
>
> Thank you and best regards,
>
> Peter
>
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