Pytorch写数字识别LeNet模型

from PIL import Image
import cv2
import matplotlib.pyplot as plt
import torchvision
from torchvision import transforms
import torch
from torch.utils.data import DataLoader
import torch.nn as nn
import numpy as np
import tqdm as tqdm

class LeNet(nn.Module):
    def __init__(self) -> None:
        super().__init__()
        self.sequential = nn.Sequential(nn.Conv2d(1,6,kernel_size=5,padding=2),nn.Sigmoid(),
                                        nn.AvgPool2d(kernel_size=2,stride=2),
                                        nn.Conv2d(6,16,kernel_size=5),nn.Sigmoid(),
                                        nn.AvgPool2d(kernel_size=2,stride=2),
                                        nn.Flatten(),
                                        nn.Linear(16*25,120),nn.Sigmoid(),
                                        nn.Linear(120,84),nn.Sigmoid(),
                                        nn.Linear(84,10))
        
    
    def forward(self,x):
        return self.sequential(x)

class MLP(nn.Module):
    def __init__(self) -> None:
        super().__init__()
        self.sequential = nn.Sequential(nn.Flatten(),
                          nn.Linear(28*28,120),nn.Sigmoid(),
                          nn.Linear(120,84),nn.Sigmoid(),
                          nn.Linear(84,10))
        
    
    def forward(self,x):
        return self.sequential(x)

epochs = 15
batch = 32
lr=0.9
loss = nn.CrossEntropyLoss()
model = LeNet()
optimizer = torch.optim.SGD(model.parameters(),lr)
device = torch.device('cuda')
root = r"./"
trans_compose  = transforms.Compose([transforms.ToTensor(),
                    ])
train_data = torchvision.datasets.MNIST(root,train=True,transform=trans_compose,download=True)
test_data = torchvision.datasets.MNIST(root,train=False,transform=trans_compose,download=True)
train_loader = DataLoader(train_data,batch_size=batch,shuffle=True)
test_loader = DataLoader(test_data,batch_size=batch,shuffle=False)

model.to(device)
loss.to(device)
# model.apply(init_weights)
for epoch in range(epochs):
  train_loss = 0
  test_loss = 0
  correct_train = 0
  correct_test = 0
  for index,(x,y) in enumerate(train_loader):
    x = x.to(device)
    y = y.to(device)
    predict = model(x)
    L = loss(predict,y)
    optimizer.zero_grad()
    L.backward()
    optimizer.step()
    train_loss = train_loss + L
    correct_train += (predict.argmax(dim=1)==y).sum()
  acc_train = correct_train/(batch*len(train_loader))
  with torch.no_grad():
    for index,(x,y) in enumerate(test_loader):
      [x,y] = [x.to(device),y.to(device)]
      predict = model(x)
      L1 = loss(predict,y)
      test_loss = test_loss + L1
      correct_test += (predict.argmax(dim=1)==y).sum()
    acc_test = correct_test/(batch*len(test_loader))
  print(f'epoch:{epoch},train_loss:{train_loss/batch},test_loss:{test_loss/batch},acc_train:{acc_train},acc_test:{acc_test}')

images_np = cv2.imread("/content/R-C.png",cv2.IMREAD_GRAYSCALE)
h,w = images_np.shape
images_np = np.array(255*torch.ones(h,w))-images_np#图片反色
images = Image.fromarray(images_np)
plt.figure(1)
plt.imshow(images)
test_images = []
for i in range(10):
  for j in range(16):
    test_images.append(images_np[h//10*i:h//10+h//10*i,w//16*j:w//16*j+w//16])
sample = test_images[77]
sample_tensor = torch.tensor(sample).unsqueeze(0).unsqueeze(0).type(torch.FloatTensor).to(device)
sample_tensor = torch.nn.functional.interpolate(sample_tensor,(28,28))
predict = model(sample_tensor)
output = predict.argmax()
print(output)
plt.figure(2)
plt.imshow(np.array(sample_tensor.squeeze().to('cpu')))

correct = 0
i = 0
cnt = 1
for sample in test_images:
  sample_tensor = torch.tensor(sample).unsqueeze(0).unsqueeze(0).type(torch.FloatTensor).to(device)
  sample_tensor = torch.nn.functional.interpolate(sample_tensor,(28,28))
  predict = model(sample_tensor)
  output = predict.argmax()
  if(output==i):
    correct+=1
  if(cnt%16==0):
    i+=1
  cnt+=1
acc_g = correct/len(test_images)
print(f'acc_g:{acc_g}')

acc_g:0.50625