238 lines
7.5 KiB
Python
238 lines
7.5 KiB
Python
import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from torchvision import transforms
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from PIL import Image
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class FoodCNN(nn.Module):
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"""
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食物分类CNN模型
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基于CIFAR10结构，适配3分类任务
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use_internal_preprocess 是否在模型内部预处理
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训练的时候，
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"""
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def __init__(self, use_internal_preprocess=False):
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super(FoodCNN, self).__init__()
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self.use_internal_preprocess = use_internal_preprocess
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# 图片预处理变换（仅在推理时使用）
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self.preprocess = transforms.Compose([
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transforms.Resize((32, 32),interpolation=transforms.InterpolationMode.BILINEAR),
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transforms.ToTensor(),
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transforms.Normalize((0.485, 0.456, 0.406), (0.229, 0.224, 0.225))
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])
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# 内部预处理变换（用于已经是tensor但未归一化的数据）
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self.internal_preprocess = transforms.Compose([
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# 不包含Resize，因为训练时已经在DataLoader中处理了
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transforms.Normalize((0.485, 0.456, 0.406), (0.229, 0.224, 0.225))
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])
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# 第一个卷积块
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self.conv1 = nn.Conv2d(3, 32, 3, padding=1)
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self.conv2 = nn.Conv2d(32, 32, 3, padding=1)
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self.pool1 = nn.MaxPool2d(2, 2)
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self.dropout1 = nn.Dropout2d(0.25)
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# 第二个卷积块
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self.conv3 = nn.Conv2d(32, 64, 3, padding=1)
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self.conv4 = nn.Conv2d(64, 64, 3, padding=1)
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self.pool2 = nn.MaxPool2d(2, 2)
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self.dropout2 = nn.Dropout2d(0.25)
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# 第三个卷积块
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self.conv5 = nn.Conv2d(64, 128, 3, padding=1)
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self.conv6 = nn.Conv2d(128, 128, 3, padding=1)
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self.pool3 = nn.MaxPool2d(2, 2)
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self.dropout3 = nn.Dropout2d(0.25)
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# 全连接层
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self.fc1 = nn.Linear(128 * 4 * 4, 512)
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self.dropout4 = nn.Dropout(0.5)
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self.fc2 = nn.Linear(512, 3) # 3分类
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def preprocess_image(self, image):
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"""
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预处理单张图片（使用与移动端相同的插值方法）
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Args:
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image: PIL Image 或 numpy array
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Returns:
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torch.Tensor: 预处理后的张量，形状为 (1, 3, 32, 32)
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"""
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if not isinstance(image, Image.Image):
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# 如果是numpy array，转换为PIL Image
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if hasattr(image, 'shape'):
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image = Image.fromarray(image)
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else:
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raise ValueError("输入必须是PIL Image或numpy array")
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# 转换为tensor（不做resize）
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tensor = transforms.ToTensor()(image)
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# 添加batch维度
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tensor = tensor.unsqueeze(0)
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# 使用与移动端相同的插值方法缩放到32x32
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tensor = F.interpolate(tensor, size=(32, 32), mode='bilinear', align_corners=False)
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# ImageNet标准化
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mean = torch.tensor([0.485, 0.456, 0.406]).view(1, 3, 1, 1)
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std = torch.tensor([0.229, 0.224, 0.225]).view(1, 3, 1, 1)
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tensor = (tensor - mean) / std
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return tensor
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def mobile_preprocess(self, x):
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"""
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移动端预处理（TorchScript兼容）
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Args:
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x: 输入tensor，形状为 [batch, 3, height, width]，值范围 0-255
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Returns:
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torch.Tensor: 预处理后的tensor，形状为 [batch, 3, 32, 32]
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"""
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# 归一化到 [0, 1]
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# 好像安卓已经做了归一化了。
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# x = x.float() / 255.0
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# 缩放到 32x32
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x = F.interpolate(x, size=(32, 32), mode='bilinear', align_corners=False)
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# 缩放到 32x32 - 使用 align_corners=True 来匹配 PIL 的默认行为
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# x = F.interpolate(x, size=(32, 32), mode='bilinear', align_corners=True)
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# ImageNet标准化
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mean = torch.tensor([0.485, 0.456, 0.406], device=x.device).view(1, 3, 1, 1)
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std = torch.tensor([0.229, 0.224, 0.225], device=x.device).view(1, 3, 1, 1)
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x = (x - mean) / std
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return x
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def _forward_network(self, x):
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"""
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网络的核心前向传播（不包含预处理）
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Args:
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x: 预处理后的tensor，形状为 [batch, 3, 32, 32]
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Returns:
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torch.Tensor: 模型输出
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"""
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# 第一个卷积块
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x = F.relu(self.conv1(x))
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x = F.relu(self.conv2(x))
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x = self.pool1(x)
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x = self.dropout1(x)
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# 第二个卷积块
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x = F.relu(self.conv3(x))
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x = F.relu(self.conv4(x))
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x = self.pool2(x)
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x = self.dropout2(x)
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# 第三个卷积块
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x = F.relu(self.conv5(x))
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x = F.relu(self.conv6(x))
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x = self.pool3(x)
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x = self.dropout3(x)
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# 展平
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x = x.view(-1, 128 * 4 * 4)
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# 全连接层
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x = F.relu(self.fc1(x))
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x = self.dropout4(x)
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x = self.fc2(x)
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return x
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def forward(self, x):
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# 如果启用内部预处理且输入是tensor
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if self.use_internal_preprocess and isinstance(x, torch.Tensor):
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x = self.internal_preprocess(x)
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return self._forward_network(x)
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def forward_mobile(self, x):
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"""
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移动端前向传播（包含预处理）
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Args:
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x: 输入tensor，形状为 [batch, 3, height, width]，值范围 0-255
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Returns:
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torch.Tensor: 模型输出
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"""
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# 移动端预处理
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x = self.mobile_preprocess(x)
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# 执行网络前向传播
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return self._forward_network(x)
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def create_food_cnn(use_internal_preprocess=False):
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"""
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创建食物分类CNN模型
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Args:
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use_internal_preprocess: 是否在forward中进行预处理
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Returns:
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FoodCNN: 网络模型实例
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"""
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return FoodCNN(use_internal_preprocess=use_internal_preprocess)
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def create_mobile_food_cnn():
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"""
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创建移动端食物分类CNN模型
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Returns:
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FoodCNN: 配置为移动端使用的网络模型实例
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"""
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class MobileFoodCNN(FoodCNN):
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"""
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移动端食物分类模型
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重写forward方法以包含预处理
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"""
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def __init__(self):
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super().__init__(use_internal_preprocess=False)
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def forward(self, x):
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"""
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移动端前向传播（自动包含预处理）
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Args:
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x: 输入tensor，形状为 [batch, 3, height, width]，值范围 0-255
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Returns:
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torch.Tensor: 模型输出
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"""
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return self.forward_mobile(x)
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return MobileFoodCNN()
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if __name__ == "__main__":
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# 测试网络
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model = create_food_cnn()
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print(f"模型参数数量: {sum(p.numel() for p in model.parameters() if p.requires_grad)}")
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# 测试前向传播
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dummy_input = torch.randn(1, 3, 32, 32)
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output = model(dummy_input)
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print(f"输出形状: {output.shape}")
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# 测试图片预处理
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try:
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import numpy as np
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# 创建一个测试图片 (RGB格式)
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test_image = Image.fromarray(np.random.randint(0, 255, (224, 224, 3), dtype=np.uint8))
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processed = model.preprocess_image(test_image)
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print(f"预处理后图片形状: {processed.shape}")
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print(f"预处理后数值范围: [{processed.min():.3f}, {processed.max():.3f}]")
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except Exception as e:
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print(f"预处理测试失败: {e}") |