How to is dwObject.numUndetectedFrames set/controlled?

Autonomous Vehicles DRIVE PX2 DriveWorks
#1

We’re using object detection built upon the merged outputs of the object tracker and the object detector+clustering (as described in the Development Guide). Some of the resultant merged objects have a “numUndetectedFrames” that is greater than 0. I assume this means that the object was not in the detector+clustering outputs for some amount of time.

Is there any way to control how many undetected frames should be allowed before a tracked object is considered “expired” and dropped from the list? If not, is the logic governing the expiration of such objects documented somewhere?

Thanks!

#2

Dear petexklxv,

numUndetectedFrames is used to enable decay in confidence of object tracks when there is no detection.

The logic is as follows (documented in doxygen):
if (numDetectedFrames > 0)
objectConfidence -= confRateTrackMin + (confRateTrackMax - confRateTrackMin) * (1.f - sqrt(featureCount / maxFeatureCount))

In addition, confThreshDiscard and confThreshConfirm parameters help control whether an object is expired or not. Thanks.