5. Corrections

Table of Contents

What are Corrections?

After tracking completes, the corrections stage in ABC Tracker allows for:

  • Visualizing and validating tracking results
  • Utilizing a complete set of tools to improve tracking data, both semi-automatically and manually


What are the differences between Manual Mode and Guided Mode?

Manual ModeGuided Mode
You select which track to modifyABC Tracker asks for information on a particular track
You select which operation to perform to modify the trackABC Tracker performs operations automatically based on your input
You select the time frame to adjustABC Tracker queues up a few seconds of video footage and presents it for review

In general, it is recommended to complete guided reviews first and then perform manual reviews

This is because guided reviews leverage behind-the-scenes tracking data to make semi-automatic connections, reducing the amount of manual effort to get accurate results

Guided Mode

ABC Tracker automatically generates pre-built reviews for you to complete. These are instances where ABC Tracker has some tracking data available, but needs more confidence about a particular object's location or orientation. ABC Tracker will ask questions about an object, and then use your input to track that object and/or neighboring objects automatically.


Read the complete article on Guided Mode

Manual Mode

ABC Tracker has a complete suite of tools to manually correct tracking data. These tools provide the ability to:

  • Add a new track
  • Adjust location of a track
  • Remove a track
  • Join one track with another
  • Break a track into two tracks
  • Flip orientations on a track
  • Modify orientations on a track
  • Mark a track as complete


Read the complete article on Manual Mode

What do the Markings on Objects Mean?

Solid vs. Dashed Bounding Box

The solid vs. dashed bounding boxes indicate the presence or absence of detections for an object in a specific frame:

  • A solid line means ABC Tracker has a good detection for that object in that frame
  • A dashed line means ABC Tracker did not have a good detection in that frame, but had sufficient data to place the object in that location
    • More specifically, the dashed line means ABC Tracker used interpolation to determine the exact location for the object in that frame



As Guided Reviews are completed, many of the dashed bounding boxes will disappear. This is because Guided Reviews are specifically chosen to provide ABC Tracker with the additional information it needs to have more confidence on an object's location.

Diamond on Short Edge of Bounding Box

There is a small diamond located on one end of each object. This diamond shows the position of the object's head.

If the diamond is on the wrong end of the object, it can be adjusted through a Manual Review.


Many of the incorrect orientations are automatically corrected during Guided Reviews, so often it is more efficient to complete the guided reviews first and then review the object orientations.

Orientation of Bounding Box

In ABC Tracker, the orientation of each object is visualized by the orientation of the object's bounding box. When these results are exported to CSV, the orientation is recorded using an image coordinate system (in clockwise order):


How To Perform Corrections

The method of performing corrections depends on the correction "mode." See the following pages for details on performing corrections:

Saving Your Work

ABC Tracker saves all corrections automatically. After a correction is performed, the green checkmark at the bottom-left corner of the playback window switches to a spinning gear. This indicates that ABC Tracker is processing the correction that was just completed, and the spinning gear will switch back to a green checkmark once the correction is finished processing.


Undo Recent Corrections

Corrections can be undone at any time. After pressing the "undo" button at top-left corner of the video playback window, ABC Tracker will confirm that you would like to undo the last correction operation that was performed.


After performing an "undo" operation, it is best to wait until the green checkmark is displayed in the bottom left corner of the video playback window (see "Saving Your Work" section for screenshot).

This ensures that the tracking data being shown in ABC Tracker reflects the undo operation that was performed.

Video Playback Tools

During corrections, ABC Tracker offers several video playback tools that can increase productivity.

These include:

  • Zoom
  • Video scrubbing
  • Playback speed

To read more on these tools, see Video Playback Tools

Statistics and Visualization Tabs

Correction Progress Tab

During manual mode, the correction progress tab will display three statistics:

  • Guided Progress
    • Displays how many guided reviews have been completed vs. how many reviews are currently available
  • Estimated Accuracy
    • This field is currently not in use. The development team is considering many different methods of calculating estimated accuracy.
  • Completed Tracks
    • Displays the number of tracks that are "Marked Completed" (see Manual Mode) vs. the total number of objects tracked in video

Gantt Chart Tab

The Gantt chart displays one horizontal bar for each track. The length of the bar indicates the duration of the track. The x-position of the bar indicates the time-position of the track (beginning, middle, or end of the video).

A track can be selected by clicking on its corresponding bar in the Gantt chart. Once a track is selected, manual corrections can be performed on that object.


To make the Gantt chart disappear, move the cursor off of the Gantt chart area and onto the video playback window

Visualization Properties Tab



All visualizations that are shown on the video player can be adjusted. Use the Visualization Properties tab to:

  • Shuffle the bounding box colors
  • Apply a global color for all bounding boxes
  • Distinguish completed tracks (by swapping the bounding box with a star)
  • Show/hide bounding boxes
  • Differentiate between interpolated frames using a dashed marker
  • Change between available marker types:
    • Rectangle
    • Ellipse
    • Square
    • Circle
    • Star
  • Show track ID's
  • Show tails to visualize an object's recent locations

Page Settings Tab

There are also global settings for the video playback window:

  • Show correction instructions - display instructions on how to perform corrections at the top left corner of the video playback window
  • Show faster seek frames - use a behind-the-scenes method to display the video much faster when scrubbing through video
  • Display current frame number - show/hide frame number in bottom-left corner of video playback window
  • Display zoom controls - show/hide zoom controls in bottom-right corner of video playback window