getitune applies post-training quantization (PTQ) via
NNCF to shrink an exported OpenVINO
model and speed up inference. Quantization runs on an OpenVINO model (an
exported .xml), producing an INT8 version.
Run everything from library/.
Workflow
from getitune.engine import create_engine
Load an exported OpenVINO model, then quantize it
ov_engine = create_engine( model="/path/to/exported_model.xml", data="/path/to/dataset", ) ov_engine.optimize() # INT8 post-training quantization via NNCF int8_metrics = ov_engine.test() # validate the quantized model predictions = ov_engine.predict() # run inference with the quantized model
1. **Start from an exported OpenVINO model** (`.xml`). If you only have a
checkpoint, export it first with the `getitune-exporting-a-model` skill.
- Done when: `create_engine(model="....xml", data=...)` builds an `OVEngine`.
2. **Provide a calibration dataset.** Calibration images are taken automatically
from the training subset; 200-500 images is the recommended calibration size.
- Done when: `optimize()` runs without a "not enough calibration data" issue.
3. **Run `optimize()`.** This replaces the engine's model in place with the INT8
version.
- Done when: the call completes and subsequent `test()`/`predict()` use INT8.
4. **Re-validate accuracy** with `test()` and compare against the FP32/FP16
baseline; a small accuracy drop is expected in exchange for size/latency.
- Done when: the INT8 metric is within your acceptable tolerance of baseline.
## Comparing against the original model
After `optimize()` the engine holds the INT8 model. To re-check the original
FP32/FP16 model, either pass the original `.xml` path directly to `.test()` /
`.predict()`, or create the engine again from the original `.xml`.
## Notes
- Quantization is OpenVINO/NNCF-based and applies to exported IR models — it is
not a training-time step.
- **Only OpenVINO IR (`.xml`) is supported.** An ONNX model must be converted to
OpenVINO IR first before it can be optimized.
- In the Geti application this is exposed as the `quantize` job
(`application/backend/app/execution/quantization/`); library `optimize()` is
the same capability without the job/queue wrapper.
## Verify
```bash
# from library/
just lint
just test-unit -- -k optimize # when you touched optimization code
Related skills
getitune-exporting-a-model— produce the OpenVINO.xmlto quantize.getitune-running-inference— run inference with the quantized model.