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Tracking Inspector


The Tracking Inspector panel is accessible in Expert Mode (settings -> Expert Mode), or in the Interactive panel (View -> Tracking replay).

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  • 1: Open
  • 2: Open Tracking_Result directory
  • 3: Reload
  • 4: Export video
  • 5: Undo
  • 6: Redo
  • 8: First object selection box
  • 9: Swap
  • 9: Second object selection box
  • 10: Delete one
  • 11: Delete
  • 12: Delete selection box
  • 13: Previous/Next occlusion (experimental)
  • 14: Annotation search
  • 15: Annotation previous match
  • 16: Annotation next match
  • 17: Annotation entry
  • 18: Objects information table
  • 19: Timeline
  • 20: Image number
  • 21: Play
  • 22: FPS selection box
  • 23: Display
  • 24: Overlay

The Tracking Inspector is a tool to display the result of a tracking analysis and to correct the tracking manually if necessary. For example, the user can delete an object to remove an artifact or change the object ID to correct a tracking error. To make the user's life easier, FastTrack provides an ergonomic interface with built-in keyboard shortcuts. FastTrack alleviates the tedious work of review and correction, and the user can achieve 100% tracking accuracy rapidly and efficiently.

Loading a tracking analysis#

To load a tracking analysis previously tracked in FastTrack, first, click on the Open button (1) and select a movie or an image of an image sequence. It will load the latest tracking analysis available.
If the movie was tracked several times, the last tracking analysis is stored in the Tracking_Result folder and the previous tracking analysis in the Tracking_Result_Date folders.
Old tracking analysis can be loaded using the Open Tracking_result directory button (2) (only activated if a movie is already loaded). Click on the Reload) button (3) to reload the tracking data if necessary.
The software can only load a tracking analysis if the folder architecture is preserved, .ie the folder with the image sequence or the movie has to have a sub-folder named Tracking_Result containing at least the tracking.txt file.

Display options#

Several tracking overlay options are available on the tracking overlay panel (24):

  • Ellipse: display the head, tail, and or body ellipses on the tracked objects.
  • Arrows: display an arrow on the head, tail, and or body of the tracked object indicating the orientation.
  • Numbers: display the ids of the tracked objects.
  • Traces: display the previous 50 positions of the tracked objects.
  • Size: the size of the tracking overlay.
  • Frame rate: display and saving frame rate.

Several useful information on the selected object can be found in the information table (18). The user can go to the image where the object has appeared for the first time by clicking directly on the table's corresponding cell.

Inspecting the tracking#

The tracking can be inspected by moving the display cursor (19), seeing the image number (20), and automatically playing the movie (21) at a selected frame rate (22).
Automatically detected occlusions (overlapped objects) can be reviewed by clicking on the Previous (12) and Next (13) occlusion buttons (this function is experimental and can miss some occlusions).

Annotating the tracking#

The user can annotate any image of the tracking. Write the annotation in the annotate text entry (17). The user can search across annotations with the find bar (14) and the buttons (15)(16). All the annotations are saved in the annotation.txt file in the Tracking_Result folder.

Correcting the tracking#

Swapping the data of two objects#

The user can correct an error by swapping two object's ID from the current image to the end of the sequence as follow:

  • Left-click on the first object, the object ID and color are displayed on the first selection box (6).
  • Left-click on the second object, the object ID and color are displayed on the second selection box (8)
  • Right-click or click on the Swap Button (7) to exchange the ID of the two selected objects from the current image to the last image of the sequence.

Delete the data of an object#

To delete one object of several frames:

  • Double left click on the object, the object ID and color are displayed on the second selection box (8).
  • Select the number of frames on which to delete the object in the box (11). Shortcut C is available to focus on the selection box.
  • Click on the Delete button (10) to delete the object from the current frame to the current frame plus the selected number.

To delete one object on the current frame:

  • Double left-click on the object, the object ID and color are displayed on the second selection box (8).
  • Click on the Delete One button (9) to delete the object on the current frame.

Keyboard shortcuts summary#

A set of keyboard shortcuts are available to speed up the tracking correction.

  • Q/A: go to the previous image.
  • D: go to the next image.
  • F: delete the selected object on the current image.
  • C: enter the number of images where an object has to be deleted.
  • G: delete an object from the current image to the current plus the selected number.


All the changes made in the inspector are automatically saved in the original tracking.txt file and SQLite database.

Exporting a movie#

To export a movie of a tracking analysis, select the desired display overlay and click on the Save button (3). Select a folder and a name to save the file. Only .avi format is supported.

Note: Movie with many objects by frame can be challenging to load and review in the tracking Inspector.

See a video demonstration