# OpenCV Tracker Issues
**URL:** https://forum.opencv.org/t/opencv-tracker-issues/3457
**Category:** C++
**Tags:** tracking, video, contrib
**Created:** [May 21, 2021, 7:16am UTC](https://forum.opencv.org/t/opencv-tracker-issues/3457 "2021-05-21T07:16:53Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@kohila](https://forum.opencv.org/u/kohila)
#### Post date: [May 21, 2021, 7:16am UTC](https://forum.opencv.org/t/opencv-tracker-issues/3457/1 "2021-05-21T07:16:53Z")
Dear All,
I have installed and tried opencv 3.6.0, 4.5.1 and 4.2.0.
I have integrated opencv\_tracking library in eclipse . But only 4 tracker(KCF,MIL,TLD,CSRT) API is working fine.
Remaining 4 trackers(MOSSE,BOOSTING,MEDIANFLOW,GOTURN) is throwing an error like tracker not defined.
Please let me know whats the problem ?
ThanksinAdvance,
Kohila.S
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### Author:  [@berak](https://forum.opencv.org/u/berak)
#### Post date: [May 21, 2021, 7:34am UTC](https://forum.opencv.org/t/opencv-tracker-issues/3457/2 "2021-05-21T07:34:52Z")
> [@kohila](#):
>
> Remaining 4 trackers(MOSSE,BOOSTING,MEDIANFLOW,GOTURN) is throwing an error like tracker not defined.
with 4.5.1, some of them (like goturn) were moved to the main repo (video module), others were moved to a “legacy” interface.
have a [look here, how to invoke them now](https://github.com/opencv/opencv_contrib/blob/4fc6995375e384b8e25bd6c8693fa8dd2ed4bb0a/modules/tracking/samples/samples_utility.hpp#L13-L28)
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### Author:  [@kohila](https://forum.opencv.org/u/kohila)
#### Post date: [May 22, 2021, 5:49am UTC](https://forum.opencv.org/t/opencv-tracker-issues/3457/3 "2021-05-22T05:49:43Z")
Thanks berak. Means if i add legacy.hpp file in my sample program, will MOSSE tracker work???
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### Author:  [@kohila](https://forum.opencv.org/u/kohila)
#### Post date: [May 24, 2021, 3:09pm UTC](https://forum.opencv.org/t/opencv-tracker-issues/3457/4 "2021-05-24T15:09:43Z")
Hi berak, Thanks for your valuable reply. I have integrated legacy tracker library and MOSSE is working fine.