getIndexFromLabel

[Deleted user]

this returns an error on OS X 10.10 with OF 0.8.4

int temp_index = tracker.getIndexFromLabel(i);

Tracker.h:277:28: No member named 'getIndex' in 'cv::Rect_'
i am working of the ofxCv example-contours-following.

[Kyle McDonald]

i think i just fixed this in develop, please test.

[Stephan Schulz]

still see this problem. index is always -1
contourFinder.getTracker().getIndexFromLabel(labelsSorted[0]);

while this contourFinder.getLabel(0) returns good values

[Stephan Schulz]

as further prove i added this line to the example-contours-tracking.

ofLog()<<i<<" label "<<label<<" labelB "<<contourFinder.getTracker().getLabelFromIndex(i)<<" index "<<contourFinder.getTracker().getIndexFromLabel(label);

i am using the develop branch

[Stephan Schulz]

i found a hack i think.
if i make index public here: https://github.com/kylemcdonald/ofxCv/blob/master/libs/ofxCv/include/ofxCv/Tracker.h#L60

and add this line current.back().index = index;
here
https://github.com/kylemcdonald/ofxCv/blob/master/libs/ofxCv/include/ofxCv/Tracker.h#L201
and
https://github.com/kylemcdonald/ofxCv/blob/master/libs/ofxCv/include/ofxCv/Tracker.h#L213

[tobiaszimmer]

For me its also not working.

After your hack (@stephanschulz) the function is returning values, but not the correct ones. Although the values lie within a reasonable range (always within the total number of detected contours) and there are no duplicate indices..

Any ideas @kylemcdonald , @stephanschulz ?

[John Ryan]

Seeing the same issues myself. Did you guys find a fix, @stephanschulz @tobiaszimmer ?

[John Ryan]

Building on @stephanschulz's approach, I added a setter for index (instead of making it public) and then set it explicitly each time the object is pushed back onto current. That seems to fix it. Looks like maybe the initializer isn't handling index properly. I'll give it another look and submit a pull request.

[John Ryan]

Actually I think I just misunderstood what getLabelFromIndex was for. It returns the index in the current vector, not the index in the TrackerFollower's followers vector, which is what we want. But there's a labels vector in TrackerFollower that maps to followers.

So I'm now looking up my label here instead of getLabelFromIndex and it's working:

ofApp.h

ofxCv::RectTrackerFollower<Letter> letterTracker;

ofApp.cpp

        vector<unsigned int> letterTrackerLabels = letterTracker.track(contourFinder.getBoundingRects());
        vector<Letter>& letters = letterTracker.getFollowers();
        const vector<unsigned int>& newLabels = letterTracker.getNewLabels();

        // Find the Letter for any new Labels and set their image
        for(int i = 0; i < newLabels.size(); i++) {
            int newLabel = newLabels[i];
            // Find position of Letter with that Label
            vector<unsigned int>::const_iterator index = find(letterTrackerLabels.begin(), letterTrackerLabels.end(), newLabel);
            if (index != letterTrackerLabels.end()) {
                int iteratorPosition = distance<vector<unsigned int>::const_iterator> (letterTrackerLabels.begin(), index);
                // If iteratorPosition is inside letters, then update image
                if (iteratorPosition >= 0 && iteratorPosition < letters.size()) {
                    letters[iteratorPosition].callMyFunctionHere();
                }
            }
        }