How can I define multiple points on a structural part, then track them in a video and plot displacement vs time graph.

I want to plot displacement of various points on the finger boundary from their mean position and plot the displacement vs point graph (or histogram say).

Answer 1

[Sharad]

Hi,

As per my understanding, you are interested in tracking a certain number of points on the finger boundary as shown in the image, and plot the displacement of these points from their mean position.

Here are some steps that you may want to follow;

• Install the computer vision toolbox from the MATLAB add on explorer.
• Read the video file using VideoReader().

video = VideoReader('video.mp4');

• Use 'ginput()' or image segmentation techniques to locate points of interest along the finger boundary.

numPoints = 5;
points = ginput(numPoints);

• You can use the PointTracker object from the computer vision toolbox to keep track of these points, and store them.

% initialize tracker 
tracker = vision.PointTracker();
initialize(tracker, points, frame);


for i = 1:video.NumFrames
    % Login implementation
end

• Use MATLAB functions like plot() to plot the displacements.

Here are some links that you might like to follow.

• ginput() -https://in.mathworks.com/help/matlab/ref/ginput.html
• Image segmentation - https://in.mathworks.com/discovery/image-segmentation.html
• Point tracking - https://in.mathworks.com/help/vision/ref/vision.pointtracker-system-object.html