Files
ModelTrainEval/scripts/prepare_yolo_dataset.py
T
Shaun ZhouandClaude Opus 5 8dc2fe6a2e feat(detect): 把弱监督框数据集链接到 data/ 并接上 YOLO 训练
第五步产出的框标签按类别分目录,便于人工核对;检测训练要的是 train/val
划分——类别写在标签第一列,不靠目录名。补上两个入口:

- scripts/prepare_yolo_dataset.py:拍平类别目录、按类别分层切分、硬链接到
  data/。分层是必需的,black 只有 53 张,随机切容易让小类在验证集里挂零。
  无框的图默认保留(检测训练里是压低误检的负样本);拍平后的同名冲突直接
  报错而不是静默覆盖。
- detect.py + configs/detect/film.yaml:包一层 ultralytics,沿用本仓库的
  配置继承、设备解析与 SwanLab 可视化。

选 YOLOv8 而不是 v11/v12:CLAUDE.md 限定只用 convolution 模型,YOLO11 骨架
里有 C2PSA、YOLO12 以注意力为主,只有 v8 的 C2f + SPPF 是纯卷积。
mosaic/mixup 关掉——每张图只有一个弱监督框,拼接后小目标被缩得更小,对
blackdot/whitedot 这类只占千分之几面积的类别是净伤害。

ultralytics 的 project 必须传绝对路径,相对路径会被它再拼到全局 settings
的 runs_dir 上,产出会跑到 runs/detect/runs/detect/<name> 去。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-11 12:05:50 +08:00

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#!/usr/bin/env python
"""把 generate_boxes.py 的产出整理成 YOLO 训练所需的数据集,放到 data/ 下。
uv run python scripts/prepare_yolo_dataset.py --source runs/boxes_gradcam
generate_boxes.py 的产出是**按类别**分目录的(便于人工核对):
```
runs/boxes_gradcam/
├── images/<类别>/<图名>.png
└── labels/<类别>/<图名>.txt
```
而 YOLO 检测训练要的是 **train/val 划分**——类别信息在标签文件的第一列里,
不靠目录名。这一步做三件事:
1. 把按类别分的目录拍平,按 train/val 重新组织;
2. **按类别分层**切分,小类不至于在验证集里挂零;
3. 全部用**硬链接**,不占额外磁盘。
```
data/<name>/
├── images/{train,val}/<图名>.png
├── labels/{train,val}/<图名>.txt
└── data.yaml
```
没有框的图(标签为空)默认保留:YOLO 训练里它们是负样本,有助于压低误检。
"""
from __future__ import annotations
import argparse
import errno
import json
import os
import random
import shutil
import sys
from collections import Counter, defaultdict
from pathlib import Path
sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
import yaml # noqa: E402
from datasets.yolo import IMAGE_SUFFIXES, write_data_yaml # noqa: E402
from utils import setup_logging # noqa: E402
logger = None
def link_or_copy(source: Path, destination: Path) -> str:
"""硬链接;跨文件系统时退回复制。"""
if destination.exists() or destination.is_symlink():
destination.unlink()
destination.parent.mkdir(parents=True, exist_ok=True)
try:
os.link(source, destination)
return "hard"
except OSError as exc:
if exc.errno != errno.EXDEV:
raise
shutil.copy2(source, destination)
return "copy"
def first_class_id(label_path: Path) -> int | None:
"""取标签里第一个框的类别下标;空标签(无框)返回 None。"""
for line in label_path.read_text(encoding="utf-8").splitlines():
line = line.strip()
if line:
return int(float(line.split()[0]))
return None
def collect(source: Path) -> list[tuple[Path, Path, int | None]]:
"""配对 images/ 与 labels/,返回 (图片, 标签, 类别下标) 列表。"""
images_root, labels_root = source / "images", source / "labels"
if not images_root.is_dir() or not labels_root.is_dir():
raise FileNotFoundError(f"{source} 下缺少 images/ 或 labels/,先跑 scripts/generate_boxes.py")
pairs = []
missing = []
for image in sorted(p for p in images_root.rglob("*") if p.suffix.lower() in IMAGE_SUFFIXES):
label = labels_root / image.relative_to(images_root).with_suffix(".txt")
if not label.exists():
missing.append(image)
continue
pairs.append((image, label, first_class_id(label)))
if missing:
raise FileNotFoundError(
f"有 {len(missing)} 张图没有对应的标签,例如 {missing[0]};"
"产出目录可能不完整,重新跑一次 generate_boxes.py"
)
if not pairs:
raise ValueError(f"{source} 下没有找到任何图片")
return pairs
def main() -> int:
global logger
parser = argparse.ArgumentParser(
description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter
)
parser.add_argument("--source", required=True, help="generate_boxes.py 的产出目录")
parser.add_argument("--out", default=None, help="输出目录;缺省 data/<source 目录名>")
parser.add_argument("--data-root", default="data", help="自动推导时的根目录,默认 data")
parser.add_argument("--val-ratio", type=float, default=0.2)
parser.add_argument("--seed", type=int, default=42)
parser.add_argument(
"--drop-empty", action="store_true",
help="丢弃没有框的图。默认保留——YOLO 训练里它们是负样本,有助于压低误检",
)
parser.add_argument("--overwrite", action="store_true", help="输出目录已存在时先清空")
parser.add_argument("--dry-run", action="store_true", help="只打印计划")
args = parser.parse_args()
source = Path(args.source)
out_dir = Path(args.out) if args.out else Path(args.data_root) / source.name
logger = setup_logging()
try:
pairs = collect(source)
except (FileNotFoundError, ValueError) as exc:
logger.error("%s", exc)
return 1
meta_path = source / "data.yaml"
if not meta_path.exists():
logger.error("找不到 %s", meta_path)
return 1
meta = yaml.safe_load(meta_path.read_text(encoding="utf-8"))
names = [meta["names"][i] for i in sorted(meta["names"])]
empty = [p for p in pairs if p[2] is None]
if args.drop_empty:
pairs = [p for p in pairs if p[2] is not None]
logger.info("来源: %s(%d 张,%d 类)", source, len(pairs), len(names))
logger.info(
"无框图片 %d 张:%s", len(empty), "已丢弃" if args.drop_empty else "保留为负样本"
)
# 按类别分层切分;无框的图单独作为一组分配,避免它们全落进同一侧
grouped: dict[int | None, list] = defaultdict(list)
for pair in pairs:
grouped[pair[2]].append(pair)
rng = random.Random(args.seed)
splits: dict[str, list] = {"train": [], "val": []}
for _class_id, group in sorted(grouped.items(), key=lambda kv: (kv[0] is None, kv[0])):
order = group[:]
rng.shuffle(order)
n_val = max(1, round(len(order) * args.val_ratio)) if len(order) > 1 else 0
splits["val"].extend(order[:n_val])
splits["train"].extend(order[n_val:])
counts = {
split: Counter(names[c] if c is not None else "(无框)" for _, _, c in items)
for split, items in splits.items()
}
logger.info("划分: train %d / val %d", len(splits["train"]), len(splits["val"]))
logger.info("%-14s %8s %8s", "类别", "train", "val")
for name in names + ["(无框)"]:
if counts["train"][name] or counts["val"][name]:
logger.info("%-14s %8d %8d", name, counts["train"][name], counts["val"][name])
if args.dry_run:
logger.info("--dry-run:未写入任何文件")
return 0
if out_dir.exists() and any(out_dir.iterdir()):
if not args.overwrite:
logger.error("%s 已存在且非空;确认要覆盖请加 --overwrite", out_dir)
return 1
shutil.rmtree(out_dir)
modes: Counter[str] = Counter()
seen: dict[str, Path] = {}
for split, items in splits.items():
for image, label, _ in items:
# 拍平之后不同类别目录下的同名文件会撞车,显式挡住
if image.name in seen:
logger.error(
"拍平后文件名冲突:%s 与 %s 同名。源数据集的文件名需要全局唯一,"
"用 scripts/export_clusters.py --prefix-parent 重新导出即可",
seen[image.name], image,
)
return 1
seen[image.name] = image
modes[link_or_copy(image, out_dir / "images" / split / image.name)] += 1
link_or_copy(label, out_dir / "labels" / split / f"{image.stem}.txt")
write_data_yaml(out_dir / "data.yaml", names, root=out_dir.resolve(),
train="images/train", val="images/val")
(out_dir / "summary.json").write_text(
json.dumps(
{
"source": str(source.resolve()),
"num_images": len(pairs),
"empty_labels": len(empty),
"dropped_empty": args.drop_empty,
"val_ratio": args.val_ratio,
"seed": args.seed,
"split_sizes": {k: len(v) for k, v in splits.items()},
"per_class": {k: dict(v) for k, v in counts.items()},
"link_modes": dict(modes),
},
ensure_ascii=False,
indent=2,
),
encoding="utf-8",
)
logger.info("链接方式: %s", dict(modes))
logger.info("完成 -> %s", out_dir)
return 0
if __name__ == "__main__":
raise SystemExit(main())