Tracker Line Count

Overview

Tracker Line Count node counts tracked objects that cross a counting line in either direction and returns directional totals plus the list of counted objects.

Use this node after Tracker. Draw a single counting line on the frame, then use Count A to B / Count B to A for footfall, vehicle flow, or similar analytics.

Input

Input Image

image required

Image frame used for visualization overlays. Connect this to a camera or upstream image output.

Tracked Objects

array required

Tracked objects from Tracker. Each object includes Track ID, Object History, Frames Since Last Update, and Tracking Time.

A Line for Counting

array required

Counting line defined as two endpoints in image coordinates. Only one line is supported.

Reset Count

boolean

When true, resets the count to zero on every execution. Useful for starting a new counting session from an external trigger.

Default: false

When Reset Count is false, Reset Interval (frames) appears:

• Number of frames after which the count automatically resets to zero. Set to 0 to disable automatic reset.
• Default: 0

Point Position

string

Which point of each bounding box is used for line-crossing tests.

Values: TOP, MIDDLE (default), BOTTOM

Allow Recount

boolean required

Whether objects can be recounted if they cross the line multiple times.

Default: false

When enabled, Recount Deadzone Width appears (default 20, minimum 1) — width of the deadzone near the line where re-entry can trigger another count.

Overlay results

boolean required

Whether to draw the counting line and results on the output frame.

Default: true

When enabled, options can include:

• Highlight When Counted (default true)
• Show Numbers (default true)
• Visualize Scale (default 1, range 0–10)
• Show Deadzone (default false)

Output

Output Image

image

Output frame with the counting line and counts drawn when overlay is enabled.

Count A to B

integer

Count of objects moving from A side to B side.

Count B to A

integer

Count of objects moving from B side to A side.

Counted Objects

array

Objects that have been counted. Each entry can include:

• Track ID
• Label
• Direction ID — AtoB or BtoA
• Timestamp (Unix ms)
• Speed (pixels/sec)
• Extra Data