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I am a research student in a university. I think I need some help.

I used a video camera to monitor the vibration of a plank. Then I should calculate the amplitude and frequency of the vibration from the frames pictures extracted from the videos.

The pictures extracted from the videos are thousands. It is really hard to do it manually.

All I need is to choose a point in the mid of the plank. Then trace the point's coordinate values in sequentially images.

I can trace one point in two pictures using order "ImageFeatureTrack", but I do not know how to apply this order to thousands of images.

aw0 = Import["E:\\ImageJ\\raw\\C000200.jpg"];
raw1 = Import["E:\\ImageJ\\raw\\C000201.jpg"];
ImageFeatureTrack[{raw0,raw1}]

Please help me, if you have any ideas about this task.

Thanks a lot.

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    – bbgodfrey
    Commented Feb 3, 2015 at 2:35
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    $\begingroup$ You do realize that we cannot access your E drive to make your code function? $\endgroup$
    – bill s
    Commented Feb 3, 2015 at 3:58
  • $\begingroup$ @bills The ExampleData function provides easily accessible example sequences. See my answer below. $\endgroup$
    – Sjoerd C. de Vries
    Commented Feb 11, 2015 at 11:51
  • $\begingroup$ I do not quite understand how to put the point and get its coordinates. It is not clear how to select the image. How to select and put an end to. Thank you! $\endgroup$
    – Alex Kulay
    Commented Feb 3, 2016 at 18:56

1 Answer 1

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Let's start with an example set everyone (at least everyone with a recent Mathematica version) should be able to use:

frames = Image /@  ExampleData[{"TestAnimation", "ToyVehicles"}][[1, 1, All, 2]]

Start with an interesting point and follow that. To get a point, just select an image, press . and select your point and copy its coordinates using ctrl+c. In this case I selected a point on the car's grille.

pos = ImageFeatureTrack[frames, {{44.0889`, 213.333`}}]

{{{44.0889, 213.333}}, {{43.7442, 205.102}}, {{45.1014, 196.86}}, {{64.4982, 189.781}}, {{83.8232, 177.966}}, {{110.223, 169.809}}, {{153.965, 169.902}}, {{195.111, 167.888}}, {Missing[]}, {Missing[]}}

Mathematica was able to track the point up to the frame where the car turned too much.

Displaying the results:

Multicolumn[
  Show[
    frames[[#]], 
    Graphics[{Point[pos[[#]]], Red, Line[pos[[1 ;; #, 1]]]}]
  ] & /@  Range[Length@frames], 
  2, Appearance -> "Horizontal"
]

Mathematica graphics

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