Is a time average or time scale possible with the line profile tool?
Robert Green
1 Posts
Hey there; I've been using Tracker for a research project in which I'm trying to track the oscillations of a liquid bead using a high speed camera. For this project, we have been using the point mass track to measure the height amplitude of the top of the bead. However, I've recently come to the conclusion that our oscillations are too small to be measured accurately in this way, but they are visible. I tried to pursue the line profile track to measure the amount of the black of the bead above a certain point, as this would provide an acceptable measure of the amplitude. To my dismay, I've found that there is no system readily available for tracking any part of the line profile over time (at the exception of perhaps copying all the data frame by frame for all 5000+ frames in our video into a spreadsheet, which would be time consuming, to say the least)
So my question is, is there any solution I might employ to create this time average a little faster using the line profile?
Attached is a still image of our bead, for context.
Re: Is a time average or time scale possible with the line profile tool? -
Douglas Brown
450 Posts
Robert, have you looked at RGB Region tracks? They measure average RGB values in a circular shape as a function of time. You might be able to use multiple regions with small diameters placed in a line to get usable data.
Another possibility is the Circle Fitter measuring tool. If you track several points (3 or more) on the diameter of your bead with Point Mass tracks then you can create a circle fitter, open the Attach Points dialog, choose attach to multiple tracks and select the point masses to attach to. The data generated by this tool includes the center position which would give you what you want. See screenshot attached.
Hope this helps! Doug
> Re: Is a time average or time scale possible with the line profile tool?
>
>
Hey there; I've been using Tracker for a research
> project in which I'm trying to track the oscillations
> of a liquid bead using a high speed camera. For this
> project, we have been using the point mass track to
> measure the height amplitude of the top of the bead.
> However, I've recently come to the conclusion that
> our oscillations are too small to be measured accurately
> in this way, but they are visible. I tried to pursue
> the line profile track to measure the amount of the
> black of the bead above a certain point, as this would
> provide an acceptable measure of the amplitude. To
> my dismay, I've found that there is no system readily
> available for tracking any part of the line profile
> over time (at the exception of perhaps copying all
> the data frame by frame for all 5000+ frames in our
> video into a spreadsheet, which would be time consuming,
> to say the least)
>
So my question is, is there
> any solution I might employ to create this time average
> a little faster using the line profile?
>
Attached
> is a still image of our bead, for context.
