Files
2026-07-13 13:17:40 +08:00

58 lines
1.7 KiB
Python

import torch
import numpy as np
from typing import Dict, Union, Callable
from PIL import Image
from constants import DatasetKey
from image_classification.imagenet import (
get_transform,
IMAGENET_WNID_TO_ID,
)
IMAGENET_JPEG_SPLIT_S3_ROOT = "s3://anyscale-imagenet/ILSVRC/Data/CLS-LOC"
IMAGENET_JPEG_SPLIT_S3_DIRS = {
DatasetKey.TRAIN: f"{IMAGENET_JPEG_SPLIT_S3_ROOT}/train",
DatasetKey.VALID: f"{IMAGENET_JPEG_SPLIT_S3_ROOT}/val",
DatasetKey.TEST: f"{IMAGENET_JPEG_SPLIT_S3_ROOT}/test",
}
def get_preprocess_map_fn(
random_transforms: bool = True,
) -> Callable[[Dict[str, Union[np.ndarray, str]]], Dict[str, torch.Tensor]]:
"""Get a map function that transforms a row to the format expected by the training loop.
Args:
random_transforms: Whether to use random transforms for training
Returns:
A function that takes a row dict with:
- "image": numpy array in HWC format
- "class": WNID string
The output is a dict with "image" and "label" keys.
"""
crop_resize_transform = get_transform(
to_torch_tensor=True, random_transforms=random_transforms
)
def map_fn(row: Dict[str, Union[np.ndarray, str]]) -> Dict[str, torch.Tensor]:
"""Process a single row into the expected format.
Args:
row: Dict containing "image" and "class" keys
Returns:
Dict with "image" and "label" keys
"""
# Convert NumPy HWC image to PIL
image_pil = Image.fromarray(row["image"])
# Apply transform (includes ToTensor + Normalize)
image = crop_resize_transform(image_pil)
# Convert label
label = IMAGENET_WNID_TO_ID[row["class"]]
return {"image": image, "label": label}
return map_fn