This software can track multiple moving objects within a video stream simultaneously, use visual features to aid in the tracking, and initiate tracks based on object detection in a subregion. A simple programmatic interface allows plugging into larger image chain modeling suites. It extracts unique visual features for aid in tracking and later analysis, and includes subfunctionality for extracting visual features about an object identified within an image frame.
Tracker Toolkit utilizes a feature extraction algorithm to tag each object with metadata features about its size, shape, color, and movement. Its functionality is independent of the scale of objects within a scene. The only assumption made on the tracked objects is that they move. There are no constraints on size within the scene, shape, or type of movement. The Tracker Toolkit is also capable of following an arbitrary number of objects in the same scene, identifying and propagating the track of each object from frame to frame. Target objects may be specified for tracking beforehand, or may be dynamically discovered within a tripwire region. Initialization of the Tracker Toolkit algorithm includes two steps: Initializing the data structures for tracked target objects, including targets preselected for tracking; and initializing the tripwire region. If no tripwire region is desired, this step is skipped. The tripwire region is an area within the frames that is always checked for new objects, and all new objects discovered within the region will be tracked until lost (by leaving the frame, stopping, or blending in to the background).
This work was done by Steven J. Lewis and David M. Palacios of Caltech for NASA’s Jet Propulsion Laboratory. NPO-48253
This Brief includes a Technical Support Package (TSP).
Tracker Toolkit
(reference NPO-48253) is currently available for download from the TSP library.
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Overview
The document outlines the Tracker Toolkit, a software tool developed by NASA's Jet Propulsion Laboratory (JPL) for multi-target tracking through a series of image frames. The primary function of the Tracker algorithm is to identify and track one or more target objects, which can either be predefined by the user or automatically detected within a specified tripwire region. This tripwire region is a designated area within the image frames where any detected objects are flagged for tracking.
The initialization of the Tracker algorithm involves two key steps: setting up data structures for the target objects and defining the tripwire region. If no tripwire region is needed, this step can be skipped. The algorithm operates in a loop, processing a sequence of index frames (individual images) to identify new objects. It first defines a search region around previously identified target locations and incorporates the tripwire regions into this area.
To detect new objects, the Tracker employs a Change Detection algorithm that identifies pixels that have changed relative to a static background image. These changed pixels are then grouped into objects using connected components analysis. The resulting pixel map highlights moving objects, which are further analyzed to extract features such as size, shape, location, and color. This feature extraction, along with position and velocity information, enhances the Tracker's ability to follow targets accurately.
Once moving objects are identified, the Tracker compares them to previously tracked target objects to determine continuity in tracking. This comparison helps resolve ambiguities and ensures that each object is consistently tracked across frames, preventing misidentification.
The document also includes information about the input and output parameters for the Tracker algorithm, although specific details about these parameters are not provided in the excerpts. The Tracker Toolkit is part of NASA's broader efforts to make aerospace-related technological advancements available for wider applications, emphasizing the importance of innovation in tracking and monitoring systems.
Overall, the Tracker Toolkit represents a significant advancement in image processing and object tracking technology, with potential applications in various fields beyond aerospace, including security, surveillance, and robotics. The document serves as a technical support package, providing essential information for users interested in utilizing the Tracker Toolkit for their projects.
