src/data_loader.py

import os
from torchvision import datasets, transforms
from torch.utils.data import DataLoader

def get_transforms(image_size=224):
    train_transforms = transforms.Compose([
        transforms.Resize((image_size, image_size)),
        transforms.RandomHorizontalFlip(),
        transforms.RandomRotation(10),
        transforms.ColorJitter(brightness=0.2, contrast=0.2),
        transforms.ToTensor(),
        transforms.Normalize([0.5]*3, [0.5]*3)
    ])

    val_test_transforms = transforms.Compose([
        transforms.Resize((image_size, image_size)),
        transforms.ToTensor(),
        transforms.Normalize([0.5]*3, [0.5]*3)
    ])

    return train_transforms, val_test_transforms

def get_dataloaders(data_dir, batch_size=32, image_size=224, num_workers=2):
    train_transforms, val_test_transforms = get_transforms(image_size)

    train_dir = os.path.join(data_dir, 'train')
    val_dir = os.path.join(data_dir, 'val')
    test_dir = os.path.join(data_dir, 'test')

    train_dataset = datasets.ImageFolder(train_dir, transform=train_transforms)
    val_dataset = datasets.ImageFolder(val_dir, transform=val_test_transforms)
    test_dataset = datasets.ImageFolder(test_dir, transform=val_test_transforms)

    train_loader = DataLoader(train_dataset, batch_size=batch_size, shuffle=True, num_workers=num_workers)
    val_loader = DataLoader(val_dataset, batch_size=batch_size, shuffle=False, num_workers=num_workers)
    test_loader = DataLoader(test_dataset, batch_size=batch_size, shuffle=False, num_workers=num_workers)

    class_names = train_dataset.classes

    return train_loader, val_loader, test_loader, class_names