Files
ModelTrainEval/scripts/export_classifier_openvino.py

156 lines
7.1 KiB
Python

#!/usr/bin/env python
"""Export RGB / 255 BCHW -> Softmax probabilities [1, C], in training class order.
Training normalization is embedded. No resize, pseudo boxes or background gating.
"""
from __future__ import annotations
import argparse
import copy
import json
import sys
from pathlib import Path
import numpy as np
import torch
import yaml
from torch import nn
sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
from models import build_model # noqa: E402
def ordered_names(names) -> list[str]:
if isinstance(names, dict):
indexed = {int(k): v for k, v in names.items()}
if set(indexed) != set(range(len(indexed))):
raise ValueError("Class IDs must be contiguous from zero")
names = [indexed[i] for i in range(len(indexed))]
if not isinstance(names, list) or not names or not all(isinstance(n, str) for n in names):
raise ValueError("Expected a nonempty class-name list or indexed mapping")
if len(set(names)) != len(names):
raise ValueError("Duplicate class names")
return names
def input_size(config: dict) -> list[int]:
size = config["data"]["image_size"]
size = [size, size] if isinstance(size, int) else list(size)
if len(size) != 2 or any(not isinstance(v, int) or v < 1 for v in size):
raise ValueError(f"Invalid training image_size: {size}")
return size
def preprocessing(config: dict, size: int | list[int]) -> float | None:
shape = [size, size] if isinstance(size, int) else list(size)
transforms = config["data"]["val_transforms"]
sequence = [t["name"] for t in transforms]
if sequence not in (["Resize", "ToTensor", "PerImageStandardize"],
["ToTensor", "PerImageStandardize"], ["Resize", "ToTensor"], ["ToTensor"]):
raise ValueError(f"Unsupported validation preprocessing: {sequence}")
eps = None
for transform in transforms:
if transform["name"] == "Resize" and list(transform["size"]) != shape:
raise ValueError("Training size differs from export input")
if transform["name"] == "PerImageStandardize":
eps = float(transform.get("eps", 1e-5))
if eps <= 0:
raise ValueError("Standardization eps must be positive")
return eps
class ClassifierProbabilities(nn.Module):
def __init__(self, classifier: nn.Module, eps: float | None = None):
super().__init__()
self.classifier, self.eps = classifier, eps
def normalize(self, x: torch.Tensor) -> torch.Tensor:
if self.eps is None:
return x
dims = (1, 2, 3)
mean = x.mean(dim=dims, keepdim=True)
# Match training torch.std(correction=1), separately for each image.
variance = ((x - mean) ** 2).sum(dim=dims, keepdim=True) / (x[0].numel() - 1)
return (x - mean) / (torch.sqrt(variance) + self.eps)
def forward(self, x: torch.Tensor) -> torch.Tensor:
return self.classifier(self.normalize(x)).softmax(dim=1)
def main() -> int:
import openvino as ov
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("--checkpoint", default="runs/classify/best.pth")
parser.add_argument("--classes", help="Training class order: classes.txt or eval_report.json")
parser.add_argument("--fp32-weights", action="store_true", help="Keep full-precision weights")
parser.add_argument("--out", required=True, help="New directory; existing directories are rejected")
args = parser.parse_args()
checkpoint, out = Path(args.checkpoint), Path(args.out)
if out.exists():
raise FileExistsError(f"Refusing to overwrite {out}")
state = torch.load(checkpoint, map_location="cpu", weights_only=False)
config = state["config"]
names = config["data"].get("classes")
if args.classes:
path = Path(args.classes)
supplied = (json.loads(path.read_text())["classes"] if path.suffix == ".json"
else path.read_text().splitlines())
if names and ordered_names(supplied) != ordered_names(names):
raise ValueError("--classes contradicts checkpoint class order")
names = supplied
if not names:
report = checkpoint.parent / "eval_report.json"
if not report.exists():
raise ValueError("No recorded class order; provide --classes (do not guess folder order)")
names = json.loads(report.read_text())["classes"]
names = ordered_names(names)
size = input_size(config)
eps = preprocessing(config, size)
model_config = copy.deepcopy(config["model"])
model_config["backbone"]["pretrained"] = False
model_config["init_from"] = None
model_config["num_classes"] = len(names)
model = build_model(model_config).eval()
model.load_state_dict(state["model"], strict=True)
wrapper = ClassifierProbabilities(model, eps).eval()
shape = [1, model_config["backbone"].get("in_channels", 3), *size]
torch.manual_seed(42)
example = torch.rand(shape)
converted = ov.convert_model(wrapper, example_input=example, input=shape)
converted.input().get_tensor().set_names({"images"})
converted.output().get_tensor().set_names({"probabilities"})
converted.set_rt_info("classify", ["model_info", "task"])
converted.set_rt_info(json.dumps(dict(enumerate(names))), ["model_info", "names"])
out.mkdir(parents=True)
arch = model_config["backbone"].get("arch", model_config["backbone"]["name"])
xml = out / f"{arch}.xml"
ov.save_model(converted, str(xml), compress_to_fp16=not args.fp32_weights)
compiled = ov.Core().compile_model(str(xml), "CPU", {"PERFORMANCE_HINT": "LATENCY"})
errors = []
with torch.inference_mode():
for sample in (example, torch.zeros_like(example), torch.ones_like(example)):
expected = wrapper(sample).numpy()
actual = compiled(sample.numpy())[compiled.output()]
assert actual.shape == (1, len(names))
assert np.isfinite(actual).all() and (actual >= 0).all() and (actual <= 1).all()
np.testing.assert_allclose(actual.sum(axis=1), 1, atol=1e-5)
np.testing.assert_allclose(actual, expected, atol=0.02, rtol=0.02)
assert actual.argmax(axis=1).tolist() == expected.argmax(axis=1).tolist()
errors.append(float(np.max(np.abs(expected - actual))))
metadata = {"task": "classify", "names": dict(enumerate(names)), "imgsz": size,
"channels": shape[1], "layout": "BCHW", "input_range": [0, 1],
"output": "softmax_probabilities", "input_shape": shape,
"output_shape": [1, len(names)], "standardize_eps": eps,
"weight_storage": "fp32" if args.fp32_weights else "fp16"}
(out / "metadata.yaml").write_text(yaml.safe_dump(metadata, allow_unicode=True))
(out / "classes.txt").write_text("\n".join(names) + "\n")
summary = {"checkpoint": str(checkpoint.resolve()), **metadata, "max_abs_errors": errors}
(out / "export.json").write_text(json.dumps(summary, ensure_ascii=False, indent=2))
print(json.dumps({"model": str(xml), **summary}, ensure_ascii=False, indent=2))
return 0
if __name__ == "__main__":
raise SystemExit(main())