# More information about int id and String unique\_object\_id in Camera.hpp

**URL:** <https://community.stereolabs.com/t/more-information-about-int-id-and-string-unique-object-id-in-camera-hpp/1906>\
**Category:** C++\
**Created:** [December 12, 2022, 10:09am UTC](https://community.stereolabs.com/t/more-information-about-int-id-and-string-unique-object-id-in-camera-hpp/1906 "2022-12-12T10:09:48Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![hgutze](https://community.stereolabs.com/user_avatar/community.stereolabs.com/hgutze/32/796_2.png) [@hgutze](https://community.stereolabs.com/u/hgutze)\
**Post date:** [December 12, 2022, 10:09am UTC](https://community.stereolabs.com/t/more-information-about-int-id-and-string-unique-object-id-in-camera-hpp/1906/1 "2022-12-12T10:09:49Z")

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Hi,

I would like to find out more about the use of the two variables `int id` and `string unique_object_id` in `Camera.hpp`. As far as I understand, both variables can be used for tracking detections, whereby `int id` is described as being able to be used for tracking objects and `unique_object_id` for AI detections. What exactly is meant here by AI detections? For `int id` I would also like to know whether a separate ID is automatically assigned for each object (e.g. Person1 = id1, Person2 = id2 if 2 people are recognized simultaneously in a frame) or whether the ID only refers to the objects in a general sense e.g. Person = id1, Vehicle = id2 etc.

Thx in advance

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**Author:** ![BenjaminV](https://community.stereolabs.com/user_avatar/community.stereolabs.com/benjaminv/32/3863_2.png) [@BenjaminV](https://community.stereolabs.com/u/BenjaminV)\
**Post date:** [December 12, 2022, 12:32pm UTC](https://community.stereolabs.com/t/more-information-about-int-id-and-string-unique-object-id-in-camera-hpp/1906/2 "2022-12-12T12:32:55Z")

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Hi,

The `unique_object_id` is used to track objects when using the [Custom detector](https://www.stereolabs.com/docs/object-detection/custom-od/).

If you are using the multi class or Human body models, use the `id` field instead.  
The `id` field is associated to one detection. If there are two objects in the scene, they will have a different id. The id can be used to track an object over time. Of course, if the object is lost and re detected again, a new ID will be associated to the object.

Best,  
Benjamin Vallon