[ITEP-89467] Tracking Evaluation Pipeline: Add jitter metrics (RMS jerk and acceleration variance)

tools/tracker/evaluation/Agents.md

@@ -63,6 +63,12 @@ Check `harnesses/README.md` for more details
 - **TrackEvalEvaluator**: `evaluators/trackeval_evaluator.py`
   Wraps TrackEval library, provides tracker output format conversion and delivers state of the art tracking metrics.
 
+- **DiagnosticEvaluator**: `evaluators/diagnostic_evaluator.py`
+  Per-frame location and distance error analysis between bipartite-matched tracker output tracks and ground-truth tracks. Produces CSV and plot outputs alongside summary scalar metrics (`DIST_T_mean`, `LOC_T_X_mae`, `LOC_T_Y_mae`, `num_matches`).
+
+- **JitterEvaluator**: `evaluators/jitter_evaluator.py`
+  Measures trajectory smoothness via RMS jerk and acceleration variance, computed from both tracker outputs and ground-truth tracks. Supports GT and ratio variants to isolate tracker-added jitter from dataset-inherent jitter.
+
 Multiple evaluators can be configured in a single YAML pipeline; each runs independently against the same tracker outputs and writes results to its own subfolder under the run output directory.
 
 Check `evaluators/README.md` for more details
@@ -75,6 +81,8 @@ Check `evaluators/README.md` for more details
   - Harness: [base/tracker_harness.py](base/tracker_harness.py)
   - Evaluator: [base/tracker_evaluator.py](base/tracker_evaluator.py)
 - **TrackEval adapter & helpers**: [evaluators/trackeval_evaluator.py](evaluators/trackeval_evaluator.py), [utils/format_converters/](./utils/format_converters.py).
+- **Jitter adapter**: [evaluators/jitter_evaluator.py](evaluators/jitter_evaluator.py).
+- **Diagnostic adapter**: [evaluators/diagnostic_evaluator.py](evaluators/diagnostic_evaluator.py).
 
 ## Guidelines for Adding New Component or Updating Existing One
 

tools/tracker/evaluation/README.md

@@ -72,6 +72,20 @@ evaluators:
   - class: evaluators.trackeval_evaluator.TrackEvalEvaluator
     config:
       metrics: [HOTA, MOTA, IDF1]
+  - class: evaluators.diagnostic_evaluator.DiagnosticEvaluator
+    config:
+      metrics: [LOC_T_X, LOC_T_Y, DIST_T]
+  - class: evaluators.jitter_evaluator.JitterEvaluator
+    config:
+      metrics:
+        [
+          rms_jerk,
+          rms_jerk_gt,
+          rms_jerk_ratio,
+          acceleration_variance,
+          acceleration_variance_gt,
+          acceleration_variance_ratio,
+        ]
 ```
 
 Run the pipeline:
@@ -128,6 +142,14 @@ evaluation/
 1. Create a new file in `evaluators/` (e.g., `custom_evaluator.py`)
 2. Implement the `TrackerEvaluator` ABC from `base/tracker_evaluator.py`
 
+### Available Evaluators
+
+| Evaluator             | Metrics                                                                                                                         | Description                                                                                                                                                           |
+| --------------------- | ------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `TrackEvalEvaluator`  | HOTA, MOTA, IDF1, and more                                                                                                      | Industry-standard tracking accuracy metrics via the TrackEval library                                                                                                 |
+| `DiagnosticEvaluator` | `LOC_T_X`, `LOC_T_Y`, `DIST_T` → summary scalars: `DIST_T_mean`, `LOC_T_X_mae`, `LOC_T_Y_mae`, `num_matches`                    | Per-frame location and distance error between matched tracker output tracks and ground-truth tracks; uses bipartite (Hungarian) assignment over overlapping frames    |
+| `JitterEvaluator`     | `rms_jerk`, `rms_jerk_gt`, `rms_jerk_ratio`, `acceleration_variance`, `acceleration_variance_gt`, `acceleration_variance_ratio` | Trajectory smoothness metrics based on numerical differentiation of 3D positions; GT and ratio variants allow comparing tracker-added jitter against test-data jitter |
+
 ## Canonical Data Formats
 
 The pipeline uses standardized data formats defined by JSON schemas to enable interoperability between components. All implementations must conform to these canonical formats.
@@ -249,7 +271,7 @@ pytest . -v -m integration
 pytest tests/ -v                     # Integration tests
 pytest datasets/tests/ -v            # Dataset unit tests
 pytest harnesses/tests/ -v           # Harness unit tests
-pytest evaluators/tests/ -v           # Evaluators unit tests
+pytest evaluators/tests/ -v          # Evaluators unit tests
 ```
 
 **Run tests from a specific file**:

tools/tracker/evaluation/evaluators/README.md

@@ -146,6 +146,91 @@ print(f"Matched pairs: {int(metrics['num_matches'])}")
 
 **Tests**: See [tests/test_diagnostic_evaluator.py](tests/test_diagnostic_evaluator.py) for unit tests covering track matching, scalar metrics, CSV output, and reset workflows.
 
+### JitterEvaluator
+
+**Purpose**: Evaluate tracker smoothness by measuring positional jitter in tracked object trajectories, and compare it against jitter already present in the ground-truth test data.
+
+**Status**: **FULLY IMPLEMENTED** — Computes RMS jerk and acceleration variance from both tracker outputs and ground-truth tracks using numerical differentiation.
+
+**Supported Metrics**:
+
+| Metric                        | Source         | Description                                                                                                       |
+| ----------------------------- | -------------- | ----------------------------------------------------------------------------------------------------------------- |
+| `rms_jerk`                    | Tracker output | RMS jerk across all tracker output tracks (m/s³)                                                                  |
+| `acceleration_variance`       | Tracker output | Variance of acceleration magnitudes across all tracker output tracks (m/s²)²                                      |
+| `rms_jerk_gt`                 | Ground truth   | Same as `rms_jerk` computed on ground-truth tracks                                                                |
+| `acceleration_variance_gt`    | Ground truth   | Same as `acceleration_variance` computed on ground-truth tracks                                                   |
+| `rms_jerk_ratio`              | Tracker / GT   | `rms_jerk` / `rms_jerk_gt` — tracker jitter relative to GT (1.0 = equal)                                          |
+| `acceleration_variance_ratio` | Tracker / GT   | `acceleration_variance` / `acceleration_variance_gt` — tracker acceleration variance relative to GT (1.0 = equal) |
+
+Comparing `rms_jerk` with `rms_jerk_gt` shows how much jitter the tracker
+adds on top of any jitter already present in the test data.
+
+**Algorithm**:
+
+All metrics are derived by applying three sequential layers of forward finite differences to 3D positions, accounting for variable time steps between frames:
+
+$$v_i = \frac{p_{i+1} - p_i}{\Delta t_i}, \quad a_i = \frac{v_{i+1} - v_i}{\Delta t_{v,i}}, \quad j_i = \frac{a_{i+1} - a_i}{\Delta t_{a,i}}$$
+
+- **rms_jerk / rms_jerk_gt**: $\sqrt{\frac{1}{N}\sum |j_i|^2}$ over all jerk samples from all tracks.
+- **acceleration_variance / acceleration_variance_gt**: $\text{Var}(|a_i|)$ over all acceleration magnitude samples from all tracks.
+- **rms_jerk_ratio / acceleration_variance_ratio**: tracker metric divided by the corresponding GT metric. Returns 0.0 when the GT denominator is zero. Values >1.0 indicate the tracker adds more jitter than is inherent in the ground truth.
+
+Minimum track length: 3 points for acceleration, 4 points for jerk. Shorter tracks are skipped; if no eligible tracks exist, the metric returns 0.0.
+
+For GT metrics, ground-truth frame numbers are converted to relative timestamps using the FPS derived from the tracker output.
+
+**Key Features**:
+
+- Builds per-track position histories from canonical tracker output format.
+- Parses MOTChallenge 3D CSV ground-truth file for GT metric computation.
+- Supports variable frame rates — time deltas are computed from actual timestamps.
+- Deduplicates frames with identical timestamps (mirrors `TrackEvalEvaluator` behaviour).
+- Sorts each track's positions by timestamp before metric computation.
+- Saves a plain-text `jitter_results.txt` summary to the configured output folder.
+
+**Usage Example**:
+
+```python
+from pathlib import Path
+from evaluators.jitter_evaluator import JitterEvaluator
+
+evaluator = JitterEvaluator()
+evaluator.configure_metrics(['rms_jerk', 'rms_jerk_gt', 'rms_jerk_ratio',
+                             'acceleration_variance', 'acceleration_variance_gt',
+                             'acceleration_variance_ratio'])
+evaluator.set_output_folder(Path('/path/to/results'))
+
+# Pass ground_truth=None to skip GT metrics
+evaluator.process_tracker_outputs(tracker_outputs, ground_truth=dataset.get_ground_truth())
+metrics = evaluator.evaluate_metrics()
+
+print(f"RMS Jerk (tracker): {metrics['rms_jerk']:.4f} m/s³")
+print(f"RMS Jerk (GT):      {metrics['rms_jerk_gt']:.4f} m/s³")
+print(f"RMS Jerk ratio:     {metrics['rms_jerk_ratio']:.4f}  (1.0 = equal jitter)")
+```
+
+**Pipeline Configuration**:
+
+```yaml
+evaluators:
+  - class: evaluators.jitter_evaluator.JitterEvaluator
+    config:
+      metrics:
+        [
+          rms_jerk,
+          rms_jerk_gt,
+          rms_jerk_ratio,
+          acceleration_variance,
+          acceleration_variance_gt,
+          acceleration_variance_ratio,
+        ]
+```
+
+**Implementation**: [jitter_evaluator.py](jitter_evaluator.py)
+
+**Tests**: See [tests/test_jitter_evaluator.py](tests/test_jitter_evaluator.py).
+
 ## Adding New Evaluators
 
 To add support for a new metric computation library:

tools/tracker/evaluation/evaluators/__init__.py

@@ -4,5 +4,6 @@
 """Evaluator implementations for tracker evaluation."""
 from .trackeval_evaluator import TrackEvalEvaluator
 from .diagnostic_evaluator import DiagnosticEvaluator
+from .jitter_evaluator import JitterEvaluator
 
-__all__ = ['TrackEvalEvaluator', 'DiagnosticEvaluator']
+__all__ = ['TrackEvalEvaluator', 'DiagnosticEvaluator', 'JitterEvaluator']