ViT-CIFAR10/Classification-noisy/scripts/dataset_utils.py

import torch
import torchvision
import torchvision.transforms as transforms
import os
import numpy as np
import random
import yaml
from torch.utils.data import TensorDataset, DataLoader

# 加载数据集

def get_cifar10_dataloaders(batch_size=128, num_workers=2, local_dataset_path=None, shuffle=False):
    """获取CIFAR10数据集的数据加载器
    
    Args:
        batch_size: 批次大小
        num_workers: 数据加载的工作进程数
        local_dataset_path: 本地数据集路径，如果提供则使用本地数据集，否则下载
        
    Returns:
        trainloader: 训练数据加载器
        testloader: 测试数据加载器
    """
    # 数据预处理
    transform_train = transforms.Compose([
        transforms.RandomCrop(32, padding=4),
        transforms.RandomHorizontalFlip(),
        transforms.ToTensor(),
        transforms.Normalize((0.4914, 0.4822, 0.4465), (0.2023, 0.1994, 0.2010)),
    ])

    transform_test = transforms.Compose([
        transforms.ToTensor(),
        transforms.Normalize((0.4914, 0.4822, 0.4465), (0.2023, 0.1994, 0.2010)),
    ])

    # 设置数据集路径
    if local_dataset_path:
        print(f"使用本地数据集: {local_dataset_path}")
        # 检查数据集路径是否有数据集，没有的话则下载
        cifar_path = os.path.join(local_dataset_path, 'cifar-10-batches-py')
        download = not os.path.exists(cifar_path) or not os.listdir(cifar_path)
        dataset_path = local_dataset_path
    else:
        print("未指定本地数据集路径，将下载数据集")
        download = True
        dataset_path = '../dataset'

    # 创建数据集路径
    if not os.path.exists(dataset_path):
        os.makedirs(dataset_path)

    trainset = torchvision.datasets.CIFAR10(
        root=dataset_path, train=True, download=download, transform=transform_train)
    trainloader = torch.utils.data.DataLoader(
        trainset, batch_size=batch_size, shuffle=shuffle, num_workers=num_workers)

    testset = torchvision.datasets.CIFAR10(
        root=dataset_path, train=False, download=download, transform=transform_test)
    testloader = torch.utils.data.DataLoader(
        testset, batch_size=batch_size, shuffle=shuffle, num_workers=num_workers)

    return trainloader, testloader

def get_noisy_cifar10_dataloaders(batch_size=128, num_workers=2, local_dataset_path=None, shuffle=False):
    """获取添加噪声后的CIFAR10数据集的数据加载器
    
    Args:
        batch_size: 批次大小
        num_workers: 数据加载的工作进程数
        local_dataset_path: 本地数据集路径，如果提供则使用本地数据集，否则下载
        shuffle: 是否打乱数据
        
    Returns:
        noisy_trainloader: 添加噪声后的训练数据加载器
        testloader: 正常测试数据加载器
    """
    # 加载原始数据集
    trainloader, testloader = get_cifar10_dataloaders(
        batch_size=batch_size,
        num_workers=num_workers,
        local_dataset_path=local_dataset_path,
        shuffle=False 
    )
    
    # 设置设备
    device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
    print(f"使用设备: {device}")
    
    # 加载配置文件
    config_path = './train.yaml'
    try:
        with open(config_path, 'r') as f:
            config = yaml.safe_load(f)
    except FileNotFoundError:
        print(f"找不到配置文件: {config_path}，使用默认配置")
        config = {
            'noise_levels': {
                'gaussian': [0.1, 0.3],
                'salt_pepper': [0.05, 0.1],
                'poisson': [1.0]
            }
        }
    
    # 加载噪声参数
    noise_levels = config.get('noise_levels', {})
    gaussian_level = noise_levels.get('gaussian', [0.1, 0.2])
    salt_pepper_level = noise_levels.get('salt_pepper', [0.05, 0.1])
    poisson_level = noise_levels.get('poisson', [1.0])[0]
    
    # 获取原始数据和标签
    data_list = []
    targets_list = []
    
    for inputs, targets in trainloader:
        data_list.append(inputs)
        targets_list.append(targets)
    
    # 合并所有批次数据
    all_data = torch.cat(data_list)
    all_targets = torch.cat(targets_list)
    
    # 创建噪声信息字典
    noise_info = {
        'noise_types': [],
        'noise_levels': [],
        'noise_indices': []
    }
    
    # CIFAR10标准化参数
    mean = torch.tensor([0.4914, 0.4822, 0.4465]).view(3, 1, 1).to(device)
    std = torch.tensor([0.2023, 0.1994, 0.2010]).view(3, 1, 1).to(device)
    
    print("开始添加噪声...")
    
    # 按标签分组进行处理
    for label_value in range(10):
        # 找出所有具有当前标签的样本索引
        indices = [i for i in range(len(all_targets)) if all_targets[i].item() == label_value]
        
        noise_type = None
        noise_ratio = 0.0
        level = None
        
        # 根据标签决定噪声类型和强度
        if label_value == 2:  # 高斯噪声强 - 30%数据
            noise_type = 1  # 高斯噪声
            noise_ratio = 0.3
            level = gaussian_level[1] if len(gaussian_level) > 1 else gaussian_level[0]
        elif label_value == 3:  # 高斯噪声弱 - 10%数据
            noise_type = 1  # 高斯噪声
            noise_ratio = 0.1
            level = gaussian_level[0]
        elif label_value == 4:  # 椒盐噪声强 - 30%数据
            noise_type = 2  # 椒盐噪声
            noise_ratio = 0.3
            level = salt_pepper_level[1] if len(salt_pepper_level) > 1 else salt_pepper_level[0]
        elif label_value == 5:  # 椒盐噪声弱 - 10%数据
            noise_type = 2  # 椒盐噪声
            noise_ratio = 0.1
            level = salt_pepper_level[0]
        elif label_value == 6:  # 泊松噪声 - 30%数据
            noise_type = 3  # 泊松噪声
            noise_ratio = 0.3
            level = poisson_level
        elif label_value == 7:  # 泊松噪声 - 10%数据
            noise_type = 3  # 泊松噪声
            noise_ratio = 0.1
            level = poisson_level
        
        # 如果需要添加噪声
        if noise_type is not None and level is not None and noise_ratio > 0:
            # 计算要添加噪声的样本数量
            num_samples_to_add_noise = int(len(indices) * noise_ratio)
            if num_samples_to_add_noise == 0 and len(indices) > 0:
                num_samples_to_add_noise = 1  # 至少添加一个样本
            
            # 随机选择要添加噪声的样本索引
            indices_to_add_noise = random.sample(indices, min(num_samples_to_add_noise, len(indices)))
            
            print(f"标签 {label_value}: 为 {len(indices_to_add_noise)}/{len(indices)} 个样本添加噪声类型 {noise_type}，强度 {level}")
            
            # 为选中的样本添加噪声
            for i in indices_to_add_noise:
                # 获取当前图像
                img = all_data[i].to(device)
                
                # 反标准化
                img_denorm = img * std + mean
                
                # 添加噪声
                if noise_type == 1:  # 高斯噪声
                    # 转为numpy处理
                    img_np = img_denorm.cpu().numpy()
                    img_np = np.transpose(img_np, (1, 2, 0))  # C x H x W -> H x W x C
                    img_np = np.clip(img_np, 0, 1) * 255.0
                    
                    # 添加高斯噪声
                    std_dev = level * 25
                    noise = np.random.normal(0, std_dev, img_np.shape)
                    noisy_img = img_np + noise
                    noisy_img = np.clip(noisy_img, 0, 255)
                    
                    # 转回tensor
                    noisy_img = noisy_img / 255.0
                    noisy_img = np.transpose(noisy_img, (2, 0, 1))  # H x W x C -> C x H x W
                    noisy_tensor = torch.from_numpy(noisy_img.astype(np.float32)).to(device)
                
                elif noise_type == 2:  # 椒盐噪声
                    # 转为numpy处理
                    img_np = img_denorm.cpu().numpy()
                    img_np = np.transpose(img_np, (1, 2, 0))  # C x H x W -> H x W x C
                    img_np = np.clip(img_np, 0, 1) * 255.0
                    
                    # 创建掩码
                    mask = np.random.random(img_np.shape[:2])
                    # 椒噪声 (黑点)
                    img_np_copy = img_np.copy()
                    img_np_copy[mask < level/2] = 0
                    # 盐噪声 (白点)
                    img_np_copy[mask > 1 - level/2] = 255
                    
                    # 转回tensor
                    noisy_img = img_np_copy / 255.0
                    noisy_img = np.transpose(noisy_img, (2, 0, 1))  # H x W x C -> C x H x W
                    noisy_tensor = torch.from_numpy(noisy_img.astype(np.float32)).to(device)
                
                elif noise_type == 3:  # 泊松噪声
                    # 转为numpy处理
                    img_np = img_denorm.cpu().numpy()
                    img_np = np.transpose(img_np, (1, 2, 0))  # C x H x W -> H x W x C
                    img_np = np.clip(img_np, 0, 1) * 255.0
                    
                    # 添加泊松噪声
                    lam = np.maximum(img_np / 255.0 * 10.0, 0.0001)
                    noisy_img = np.random.poisson(lam) / 10.0 * 255.0
                    noisy_img = np.clip(noisy_img, 0, 255)
                    
                    # 转回tensor
                    noisy_img = noisy_img / 255.0
                    noisy_img = np.transpose(noisy_img, (2, 0, 1))  # H x W x C -> C x H x W
                    noisy_tensor = torch.from_numpy(noisy_img.astype(np.float32)).to(device)
                
                # 重新标准化
                noisy_tensor_norm = (noisy_tensor - mean) / std
                
                # 更新数据
                all_data[i] = noisy_tensor_norm
                
                # 记录噪声信息
                noise_info['noise_types'].append(noise_type)
                noise_info['noise_levels'].append(level)
                noise_info['noise_indices'].append(i)
    
    # 保存添加噪声的样本索引
    noise_indices = sorted(noise_info['noise_indices'])
    noise_index_path = os.path.join('..', 'dataset', 'noise_index.npy')
    os.makedirs(os.path.dirname(noise_index_path), exist_ok=True)
    np.save(noise_index_path, noise_indices)
    print(f"已保存噪声样本索引到 {noise_index_path}，共 {len(noise_indices)} 个样本")
    
    # 创建新的TensorDataset
    noisy_dataset = TensorDataset(all_data, all_targets)
    
    # 创建新的DataLoader
    noisy_trainloader = DataLoader(
        noisy_dataset,
        batch_size=batch_size,
        shuffle=shuffle,
        num_workers=num_workers
    )
    
    print(f"成功为{len(noise_info['noise_indices'])}/{len(all_data)} ({len(noise_info['noise_indices'])/len(all_data)*100:.1f}%)的样本添加噪声")
    return noisy_trainloader, testloader