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ObjectTrackingData[…]

is an object representing a list of tracked bounding boxes or other objects.

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ObjectTrackingData

ObjectTrackingData[…]

is an object representing a list of tracked bounding boxes or other objects.

Details

  • ObjectTrackingData contains information about objects that are tracked over time. Tracked objects are also known as tracklets.
  • ObjectTrackingData is returned from VideoObjectTracking and other functions.
  • For a tracked object tracked, tracked[elem] gives objects and their properties.
  • Possible values for elements elem are:
  • labelcorresponding to a specific label
    propproperty prop for given tracklets
    label->propproperties for the given label
  • A list of available labels label can be obtained using tracked["Labels"].
  • Global properties include:
  • "Labels"list of tracked labels
    "Length"number of times, frames or steps
    "TimedQ"returns True if times are present
    "Times"times for each frame, if present
    "Type"type of tracked objects
  • Possible types are "BoundingBoxes", "Points" and "LabelMatrices".
  • Time-related properties, given as a time series for each label:
  • "FirstFrame"first frame in which a label appears
    "FirstTime"first time in which a label is present
    "LastTime"last time in which a label is present
    "TimeInterval"first and last time in which a label is present
  • Properties for "BoundingBoxes" type objects include:
  • "BoundingBox"bounding boxes as Rectangle[{xmin,ymin},{xmax,ymax}] (main)
    "Dimension"dimensions given as {width,height}
    "Position"center of the bounding box given as {x,y}
    "MaxDimension"max dimension for each label given as {maxWidth,maxHeight}
    "SubVideo"video of the tracked bounding boxes for each label
  • Properties for an object of the "Points" type include:
  • "Point"points for for each time given as Point[{x,y}] (main)
    "Position"positions for each time given as {x,y}
  • Properties for an object of the "LabelMatrices" type include:
  • "Matrix"tracked label matrices (main)
    "ColorizedImage"colorized version of the label matrices
  • For timed ObjectTrackingData, the type-specific properties are returned as TimeSeries.
  • With no times present, time-related properties are equivalent to indices. Other type-specific properties are returned as lists.
  • The following operations on ObjectTrackingData are supported:
  • Normal[tracked]the main property for each type with times if available
    Dataset[tracked]a dataset of the main property for each type with times if available
    Tabular[tracked]a tabular of the main property for each type with times if available
    TimeSeries[tracked]a time series of the main property for each type if available
    EventSeries[tracked]an event series of the main property for each type if available

Examples

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Basic Examples  (1)

Detect and track objects in a video:

Wolfram Language code: v = \!\(\*VideoBox["![Embedded Video Player](video://content-mq8bt)"]\); t = VideoObjectTracking[v]

First time when each label shows:

Wolfram Language code: t["FirstTime"]

Highlight tracked objects on the video:

Wolfram Language code: HighlightVideo[v, t]

Scope  (8)

Extract the labels of an ObjectTrackingData object:

Wolfram Language code: otd = ObjectTrackingData[Association["ObjectNames" -> {{Entity["Concept", "Auto::p735c"], 1}, {Entity["Concept", "Auto::p735c"], 2}, {Entity["Concept", "Auto::p735c"], 3}}, "Times" -> {0.01, 0.05, 0.09, 0.13, 0.16999999999999998, 0.21000000000000 ... }, ImageSize -> 225, PlaybackSettings -> Association["Position" -> 0., "CurrentVideoTrack" -> 1, "CurrentAudioTrack" -> 1, "CurrentSubtitleTrack" -> 0], SoundVolume -> 1, SubtitleTrackSelection -> {}, VideoTrackSelection -> {1}]]];
Wolfram Language code: otd["Labels"]

Extract the position of the tracked objects:

Wolfram Language code: otd["Position"]

Select only 2 tracks within an ObjectTrackingData object:

Wolfram Language code: otd = ObjectTrackingData[Association["ObjectNames" -> {{Entity["Concept", "Auto::p735c"], 1}, {Entity["Concept", "Auto::p735c"], 2}, {Entity["Concept", "Auto::p735c"], 3}, {Entity["Concept", "Auto::p735c"], 4}, {Entity["Concept", "Auto::p735c"] ... }, ImageSize -> 225, PlaybackSettings -> Association["Position" -> 0., "CurrentVideoTrack" -> 1, "CurrentAudioTrack" -> 1, "CurrentSubtitleTrack" -> 0], SoundVolume -> 1, SubtitleTrackSelection -> {}, VideoTrackSelection -> {1}]]];
Wolfram Language code: RandomSample[otd["Labels"], 2] otd[%]

Extract multiple properties at the same time:

Wolfram Language code: otd = ObjectTrackingData[Association["ObjectNames" -> {{Entity["Concept", "Auto::p735c"], 5}, {Entity["Concept", "Auto::p735c"], 4}}, "Times" -> {0.01, 0.05, 0.09, 0.13, 0.16999999999999998, 0.21000000000000002, 0.25, 0.29000000000000004, 0. ... }, ImageSize -> 225, PlaybackSettings -> Association["Position" -> 0., "CurrentVideoTrack" -> 1, "CurrentAudioTrack" -> 1, "CurrentSubtitleTrack" -> 0], SoundVolume -> 1, SubtitleTrackSelection -> {}, VideoTrackSelection -> {1}]]];
Wolfram Language code: otd[{"BoundingBox", "TimeInterval"}]//Transpose

Extract properties for a specific object:

Wolfram Language code: otd = ObjectTrackingData[Association["ObjectNames" -> {{Entity["Concept", "Auto::p735c"], 5}, {Entity["Concept", "Auto::p735c"], 4}}, "Times" -> {0.01, 0.05, 0.09, 0.13, 0.16999999999999998, 0.21000000000000002, 0.25, 0.29000000000000004, 0. ... }, ImageSize -> 225, PlaybackSettings -> Association["Position" -> 0., "CurrentVideoTrack" -> 1, "CurrentAudioTrack" -> 1, "CurrentSubtitleTrack" -> 0], SoundVolume -> 1, SubtitleTrackSelection -> {}, VideoTrackSelection -> {1}]]];
Wolfram Language code: otd[{Entity["Concept", "Auto::p735c"], 5} -> "BoundingBox"]

Extract properties for multiple objects:

Wolfram Language code: otd[{{Entity["Concept", "Auto::p735c"], 4}, {Entity["Concept", "Auto::p735c"], 5}} -> "BoundingBox"]

Construct a Tabular object from ObjectTrackingData:

Wolfram Language code: Tabular[ObjectTrackingData[Association["ObjectNames" -> {{Entity["Concept", "Auto::p735c"], 5}, {Entity["Concept", "Auto::p735c"], 4}}, "Times" -> {0.01, 0.05, 0.09, 0.13, 0.16999999999999998, 0.21000000000000002, 0.25, 0.29000000000000004, 0. ... }, ImageSize -> 225, PlaybackSettings -> Association["Position" -> 0., "CurrentVideoTrack" -> 1, "CurrentAudioTrack" -> 1, "CurrentSubtitleTrack" -> 0], SoundVolume -> 1, SubtitleTrackSelection -> {}, VideoTrackSelection -> {1}]]]]

Construct a Dataset from ObjectTrackingData:

Wolfram Language code: Dataset[ObjectTrackingData[Association["ObjectNames" -> {{Entity["Concept", "Auto::p735c"], 5}, {Entity["Concept", "Auto::p735c"], 4}}, "Times" -> {0.01, 0.05, 0.09, 0.13, 0.16999999999999998, 0.21000000000000002, 0.25, 0.29000000000000004, 0. ... }, ImageSize -> 225, PlaybackSettings -> Association["Position" -> 0., "CurrentVideoTrack" -> 1, "CurrentAudioTrack" -> 1, "CurrentSubtitleTrack" -> 0], SoundVolume -> 1, SubtitleTrackSelection -> {}, VideoTrackSelection -> {1}]]]]

Construct a TimeSeries from ObjectTrackingData:

Wolfram Language code: TimeSeries[ObjectTrackingData[Association["ObjectNames" -> {{Entity["Concept", "Auto::p735c"], 5}, {Entity["Concept", "Auto::p735c"], 4}}, "Times" -> {0.01, 0.05, 0.09, 0.13, 0.16999999999999998, 0.21000000000000002, 0.25, 0.29000000000000004, 0. ... }, ImageSize -> 225, PlaybackSettings -> Association["Position" -> 0., "CurrentVideoTrack" -> 1, "CurrentAudioTrack" -> 1, "CurrentSubtitleTrack" -> 0], SoundVolume -> 1, SubtitleTrackSelection -> {}, VideoTrackSelection -> {1}]]]]
Wolfram Language code: %[.2]

Extract all the data from ObjectTrackingData:

Wolfram Language code: Normal[ObjectTrackingData[Association["ObjectNames" -> {{Entity["Concept", "Auto::p735c"], 5}, {Entity["Concept", "Auto::p735c"], 4}}, "Times" -> {0.01, 0.05, 0.09, 0.13, 0.16999999999999998, 0.21000000000000002, 0.25, 0.29000000000000004, 0. ... }, ImageSize -> 225, PlaybackSettings -> Association["Position" -> 0., "CurrentVideoTrack" -> 1, "CurrentAudioTrack" -> 1, "CurrentSubtitleTrack" -> 0], SoundVolume -> 1, SubtitleTrackSelection -> {}, VideoTrackSelection -> {1}]]]]//Short
Wolfram Research (2025), ObjectTrackingData, Wolfram Language function, https://reference.wolfram.com/language/ref/ObjectTrackingData.html.

Text

Wolfram Research (2025), ObjectTrackingData, Wolfram Language function, https://reference.wolfram.com/language/ref/ObjectTrackingData.html.

CMS

Wolfram Language. 2025. "ObjectTrackingData." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/ObjectTrackingData.html.

APA

Wolfram Language. (2025). ObjectTrackingData. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/ObjectTrackingData.html

BibTeX

@misc{reference.wolfram_2026_objecttrackingdata, author="Wolfram Research", title="{ObjectTrackingData}", year="2025", howpublished="\url{https://reference.wolfram.com/language/ref/ObjectTrackingData.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_objecttrackingdata, organization={Wolfram Research}, title={ObjectTrackingData}, year={2025}, url={https://reference.wolfram.com/language/ref/ObjectTrackingData.html}, note=[Accessed: 12-June-2026]}