Open CV tracking the same blob over multiple frames

Dana_Avesar · February 24, 2016, 3:14pm

I am trying to track multiple people with the kinect over time, so I want to know and record when someone has left, entered, and where they move. In other words I need to keep track of the blobs over multiple frames.

The problem is that the blob array blobs[i], is refreshing every frame, and therefore what used to be blob 0 (blobs[0]) might now be blobs[1]. I can’t seem to figure out in what order its detecting and inserting the blobs into the array every frame. Currently my application is drawing lines with the blobs[i].boundingRect information, but for example the line for blobs[0] is formed from multiple objects since in a new frame blob[0] might not be the same object in the scene.

Dana

Kj1 · February 24, 2016, 3:39pm

check out ofxCV’s (not ofxOpenCv) example tracker (https://github.com/kylemcdonald/ofxCv/tree/master/example-contours-tracking)

Dana_Avesar · February 24, 2016, 10:09pm

Unfortunately the ofxCv code is much harder for me to understand than the openCv. how to use the ofCv functions. Is there an explanation you know of anywhere?

Kj1 · February 25, 2016, 9:11am

it’s well worth your time for tracking objects over multiple frames; try to study the readme and work your way through the contour examples. Otherwise you’ll need to make a tracker from scratch, and that will probably take more time.

stephanschulz · February 25, 2016, 12:25pm

try this:

it’s bit messy. the read labels are blobs that disappeared but are still remembered, they might come back alive.
the black labels are alive.