Files
LDETR_V1/data/tusimple.py
2026-08-18 18:50:32 +05:30

98 lines
3.4 KiB
Python

"""TuSimple (mask-based) dataset loader.
The data on disk (`<root>/training/{frames,lane-masks}/`) is a segmentation-style
export rather than the official `label_data_*.json` point annotations, and has no
official val/test split (see project plan §3.2). This loader:
1. Pairs each frame with its mask by filename.
2. Extracts per-lane polylines from the mask via `utils.mask_to_lanes`.
3. Applies the letterbox/normalize/(flip) transform pipeline to produce
fixed-size training targets.
4. Carves a seeded train/val split from the single available folder.
"""
from __future__ import annotations
import os
import random
from pathlib import Path
import cv2
import torch
from torch.utils.data import Dataset
from utils.mask_to_lanes import mask_to_lanes
from data.transforms import build_transforms
class TuSimpleMaskDataset(Dataset):
def __init__(
self,
root: str,
split: str,
out_w: int,
out_h: int,
max_lanes: int,
num_sample_ys: int,
val_fraction: float = 0.1,
seed: int = 42,
):
assert split in ("train", "val")
self.root = Path(root)
frames_dir = self.root / "training" / "frames"
masks_dir = self.root / "training" / "lane-masks"
frame_files = sorted(f for f in os.listdir(frames_dir) if f.lower().endswith((".jpg", ".jpeg", ".png")))
pairs = [f for f in frame_files if (masks_dir / f).exists()]
if not pairs:
raise RuntimeError(f"No matching frame/mask pairs found under {self.root}")
rng = random.Random(seed)
shuffled = pairs[:]
rng.shuffle(shuffled)
n_val = max(1, int(len(shuffled) * val_fraction))
val_set = set(shuffled[:n_val])
if split == "val":
self.files = [f for f in pairs if f in val_set]
else:
self.files = [f for f in pairs if f not in val_set]
self.frames_dir = frames_dir
self.masks_dir = masks_dir
self.transforms = build_transforms(out_w, out_h, max_lanes, num_sample_ys, train=(split == "train"))
def __len__(self) -> int:
return len(self.files)
def __getitem__(self, idx: int) -> dict:
fname = self.files[idx]
image_bgr = cv2.imread(str(self.frames_dir / fname))
mask = cv2.imread(str(self.masks_dir / fname))
if image_bgr is None or mask is None:
raise RuntimeError(f"Failed to read {fname} from {self.frames_dir} / {self.masks_dir}")
image = cv2.cvtColor(image_bgr, cv2.COLOR_BGR2RGB)
lanes = mask_to_lanes(mask)
sample = {"image": image, "lanes": lanes, "name": fname}
sample = self.transforms(sample)
return sample
def collate_fn(batch: list[dict]) -> dict:
images = torch.stack([b["image"] for b in batch], dim=0)
target_xs = torch.stack([b["target_xs"] for b in batch], dim=0)
target_valid_mask = torch.stack([b["target_valid_mask"] for b in batch], dim=0)
target_lane_valid = torch.stack([b["target_lane_valid"] for b in batch], dim=0)
target_endpoints = torch.stack([b["target_endpoints"] for b in batch], dim=0)
sample_ys = batch[0]["sample_ys"]
names = [b["name"] for b in batch]
return {
"images": images,
"target_xs": target_xs,
"target_valid_mask": target_valid_mask,
"target_lane_valid": target_lane_valid,
"target_endpoints": target_endpoints,
"sample_ys": sample_ys,
"names": names,
}