Tracking Settings Guide

← Back to Home

# Tracking Settings

Configure the parameters for the OpenLPT tracking pipeline. Proper path setup is critical for automatic parameter initialization.

Prerequisites for Best Results:

- Calibration Accuracy: Ensure your camera parameters are accurate. Aim for a 2D Projection Error < 1.0 pixel.
- Image Quality: In Image Preprocessing, ensure a high Signal-to-Noise Ratio (SNR).
- Thresholding: For tracers, set the Intensity Threshold (in Object Settings) to a value that clearly separates particles from background noise.

## 1. Project Directory

This is the first and most important step.

- Automatic Loading: Generally, the Project Path, Image Path, and Camera Path will be automatically populated from previous modules (Camera Calibration and Image Preprocessing).
- Manual Setup: If no paths are pre-loaded, you must manually select the correct directories.
- Requirement: The Camera Path directory must contain valid camera parameter files (e.g., `cam0.txt`, `cam1.txt`...). Without these, the system cannot automatically calculate the default Volume Size or IPR Tolerances.

## 2. Basic Settings

### Coordinate System & Volume

- Voxel to mm: Scaling factor (e.g., 0.001).
- View Volume (X/Y/Z):
  Auto-Calculated: If the Camera Path is valid, the View Volume boundaries are automatically calculated to cover the calibrated area. You typically do not need to change these values manually.

### Sequence

- Frame Start / End: Range of frames to process.
- FPS: Frame rate of the recording.

## 3. IPR (Iterative Particle Reconstruction)

Parameters for triangularizing 3D particles from 2D images.

- 2D Tolerance (px) & 3D Tolerance (voxel):
  Auto-Calculated: Like the View Volume, these tolerances are derived automatically from your camera parameters. No manual adjustment is usually required.
- IPR Loops: Total triangulation iterations (default: 4).

## 4. Object Settings

⚠️ User Attention Required: This is the primary area where you must tune parameters based on your specific experiment.

### If tracking Tracers:

- Intensity Threshold: The most critical parameter. Set this high enough to eliminate background noise but low enough to detect valid particles.
- Tracer Radius: Expected particle radius in pixels.

### If tracking Bubbles:

- Min / Max Bubble Radius: Define the size range of bubbles you want to track. Correctly setting these bounds is essential for filtering out debris or wrong-sized objects.

## 5. STB (Shake-The-Box)

Advanced Lagrangian tracking algorithm.

- Initial Phase: Search radius and required frame count to start a track.
- Convergence Phase: Expected particle spacing.
- Predict Field: Grid resolution for velocity prediction.
- Shake: Optimization amplitude and ghost particle threshold.

## Actions

- Validate Settings: Checks consistency of paths and parameters.
- Save Configuration: Writes `config.txt` to the Project Directory.