Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Optical flow and tracklets

Optical flow and tracklets

Optical flow and tracklets

I am using a traffic video - and obtained the motion vectors by means of optical flow. Now i want to extract tracklets (small tracjectories) by temporally connecting motion vectors e.g. at pixel level.
How may I do this please?
Also, how may I save the tracklets values after? as i am unsure of the best way to do this.
Thanks alot

RE: Optical flow and tracklets

Haven't got one as I'm doing this on my own.
I don't want anyone to give me the code I just want advise on how to proceed... then i'll try and figure it out in matlab :)

RE: Optical flow and tracklets

well loosely speaking you need to find the tracklet in the next frame that starts where the tracklet in the previous frame ends. Since I don't have much of an idea what form your data takes, that'd be as much as I can guess.


for each tracklet at time t, identify the location of the end of the tracklet, and then look in the data for t+1 and find the tracklet that starts near there.


Greg Locock

New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: Optical flow and tracklets

How many "tracklets" are we talking? dozens, hundreds, thousands?

In any case, as Greg as stated, the object is to correlate each tracklet in each frame with its counterpart in each subsequent frame. This is typically based on comparing the various parameters of each tracklet, such as position, speed, size, etc., and assigning a score for each comparison that allows the tracker to automatically determine what the true track is. In many systems, there may be multiple possible correlations, and the tracker tries to maintain each one as long as plausible. Note that in complex scenes, there may be dozens of erroneous cross-correlations that must eventually die or be killed off.

You may want to consult a good textbook, such as:
Multiple-target Tracking with Radar Applications by S. Blackman, Artech House
Multitarget-Multisensor Tracking by Y. Bar-Shalom, Artech House

Artech House is probably a good go-to publisher for this subject. The other large resource is IEEE, which has published tons of articles on trackers.

FAQ731-376: Eng-Tips.com Forum Policies

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close