主要参考:
- 官方教程：https://pytorch.org/tutorials/beginner/transfer_learning_tutorial.html
- https://github.com/pytorch/tutorials/blob/main/beginner_source/transfer_learning_tutorial.py
一、分类模型训练
引入数据集
# Data augmentation and normalization for training
# Just normalization for validation
data_transforms = {
'train': transforms.Compose([
transforms.RandomResizedCrop(224),
transforms.RandomHorizontalFlip(),
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225]
)
]),
'val': transforms.Compose([
transforms.Resize(256),
transforms.CenterCrop(224),
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
]),
}
data_dir='train_cls/23_0421_text_cls2'
# data_dir='/data2/zengxingyu2/code/23_0420_cls_text/23_0421_text_cls2'
batch_size=8
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
image_datasets = {
x: datasets.ImageFolder(os.path.join(data_dir, x),
data_transforms[x])
for x in ['train', 'val']}
dataloaders = {
x: torch.utils.data.DataLoader(image_datasets[x], batch_size=batch_size,
shuffle=True, num_workers=4)
for x in ['train', 'val']}
dataset_sizes = {
x: len(image_datasets[x]) for x in ['train', 'val']}
class_names = image_datasets['train'].classes
训练相关
def train_model(model, criterion, optimizer, scheduler, num_epochs=25):
since = time.time()
best_model_wts = copy.deepcopy(model.state_dict())
best_acc = 0.0
for epoch in range(num_epochs):
print(f'Epoch {
epoch}/{
num_epochs - 1}')
print('-' * 10)
# Each epoch has a training and validation phase
for phase in ['train', 'val']:
if phase == 'train':
model.train() # Set model to training mode
else:
model.eval() # Set model to evaluate mode
running_loss = 0.0
running_corrects = 0
# Iterate over data.
for inputs, labels in dataloaders[phase]:
inputs = inputs.to(device)
labels = labels.to(device)
# zero the parameter gradients
optimizer.zero_grad()
# forward
# track history if only in train
with torch.set_grad_enabled(phase == 'train'):
outputs = model(inputs)
_, preds = torch.max(outputs, 1)
loss = criterion(outputs, labels)
# backward + optimize only if in training phase
if phase == 'train':
loss.backward()
optimizer.step()
# statistics
running_loss += loss.item() * inputs.size(0)
running_corrects += torch.sum(preds == labels.data)
if phase == 'train':
scheduler.step()
epoch_loss = running_loss / dataset_sizes[phase]
epoch_acc = running_corrects.double() / dataset_sizes[phase]
print(f'{
phase} Loss: {
epoch_loss:.4f} Acc: {
epoch_acc:.4f}')
# deep copy the model
if phase == 'val' and epoch_acc > best_acc:
best_acc = epoch_acc
best_model_wts = copy.deepcopy(model.state_dict())
torch.save(model, 'best_model_text_cls2.pth')
print()
time_elapsed = time.time() - since
print(f'Training complete in {
time_elapsed // 60:.0f}m {
time_elapsed % 60:.0f}s')
print(f'Best val Acc: {
best_acc:4f}')
# load best model weights
model.load_state_dict(best_model_wts)
return model
可视化训练结果
def visualize_model(model, num_images=6):
was_training = model.training
model.eval()
images_so_far = 0
fig = plt.figure()
with torch.no_grad():
for i, (inputs, labels) in enumerate(dataloaders['val']):
inputs = inputs.to(device)
labels = labels.to(device)
outputs = model(inputs)
_, preds = torch.max(outputs, 1)
for j in range(inputs.size()[0]):
images_so_far += 1
ax = plt.subplot(num_images//2, 2, images_so_far)
ax.axis('off')
ax.set_title(f'predicted: {
class_names[preds[j]]}')
imshow(inputs.cpu().data[j])
if images_so_far == num_images:
model.train(mode=was_training)
return
model.train(mode=was_training)
主函数
if __name__ == '__main__':
model_ft = models.resnet18(pretrained=True)
num_ftrs = model_ft.fc.in_features
# Here the size of each output sample is set to 2.
# Alternatively, it can be generalized to ``nn.Linear(num_ftrs, len(class_names))``.
model_ft.fc = nn.Linear(num_ftrs, 2)
model_ft = model_ft.to(device)
criterion = nn.CrossEntropyLoss()
# Observe that all parameters are being optimized
optimizer_ft = optim.SGD(model_ft.parameters(), lr=0.001, momentum=0.9)
# Decay LR by a factor of 0.1 every 7 epochs
exp_lr_scheduler = lr_scheduler.StepLR(optimizer_ft, step_size=7, gamma=0.1)
######################################################################
# Train and evaluate
# ^^^^^^^^^^^^^^^^^^
#
# It should take around 15-25 min on CPU. On GPU though, it takes less than a
# minute.
#
model_ft = train_model(model_ft, criterion, optimizer_ft, exp_lr_scheduler,
num_epochs=25)
torch.save(model_ft, 'best_model_text_cls2.pth')
# visualize_model(model_ft)
运行可能会因为网络原因自行下载模型
根据提示下载模型后，放到提示位置，windows,linux都是当前用户的.cache下
Downloading: “https://download.pytorch.org/models/resnet18-f37072fd.pth” to /root/.cache/torch/hub/checkpoints/resnet18-f37072fd.pth
cp /root/.cache/torch/hub/checkpoints/resnet18-f37072fd.pth ~/.cache/torch/hub/checkpoints/resnet18-f37072fd.pth
二、flask部署代码
# -*- coding: utf-8 -*-
# @Time : 2023/4/21 16:01
# @Author : XyZeng
# -*- coding: utf-8 -*-
# @Time : 2023/4/7 10:24
# @Author : XyZeng
import io
import traceback
import requests
from flask import Flask, jsonify, request
import torch
import flask
import torchvision.transforms as transforms
from PIL import Image
app = Flask(__name__)
# 定义用于输入图像的转换
transform = transforms.Compose([
transforms.Resize((224, 224)),
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225]
)
])
def request_get(img_path,url="http://127.0.0.1:8421/cls_text?"):
params={
}
params['img_path']=img_path
response = requests.get(url, params=params)
print(response.text)
return response.text
@app.before_first_request
def load_model():
global model
# 加载模型 /data2/zengxingyu2/code/23_0330_pick_img_ocr/best_model_text_cls2.pth
model = torch.load('best_model_text_cls2.pth', map_location=torch.device('cuda'))
# 将模型设置为评估模式
model.eval()
# 定义一个函数，对输入图像进行推理
def get_prediction(image_path):
# 将图像字节转换为PIL图像对象
image = Image.open(image_path).convert('RGB')
# 对图像进行转换
image = transform(image).unsqueeze(0).to('cuda')
# ...
# 使用模型对图像进行推理
with torch.no_grad():
output = model(image)
predicted_class = torch.argmax(output, dim=1).item()
# 将预测的类别作为字符串返回
return str(predicted_class)
@app.route('/cls_text', methods=['GET'])
def predict():
try:
if flask.request.args.get("img_path"):
img_path = flask.request.args.get("img_path")
print("cls get img_path:", img_path)
# 对输入图像进行推理
prediction = get_prediction(img_path)
# print('type',type(prediction))
# 将预测的类别作为JSON响应返回
return prediction
except:
traceback.print_exc()
# results['Err']=traceback.format_exc()
return traceback.format_exc()
if __name__ == '__main__':
# python /data2/zengxingyu2/code/23_0420_cls_text/flask_torch_cls.py
app.run(debug=False, host='0.0.0.0', port=8421)
附录 完整代码
# -*- coding: utf-8 -*-
# @Time : 2023/4/21 14:58
# License: BSD
# Author: Sasank Chilamkurthy
'''
https://github.com/pytorch/tutorials/blob/main/beginner_source/transfer_learning_tutorial.py
https://pytorch.org/tutorials/beginner/transfer_learning_tutorial.html
'''
from __future__ import print_function, division
import torch
import torch.nn as nn
import torch.optim as optim
from torch.optim import lr_scheduler
import torch.backends.cudnn as cudnn
import numpy as np
import torchvision
from torchvision import datasets, models, transforms
import matplotlib.pyplot as plt
import time
import os
import copy
cudnn.benchmark = True
plt.ion() # interactive mode
# Data augmentation and normalization for training
# Just normalization for validation
data_transforms = {
'train': transforms.Compose([
transforms.RandomResizedCrop(224),
transforms.RandomHorizontalFlip(),
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225]
)
]),
'val': transforms.Compose([
transforms.Resize(256),
transforms.CenterCrop(224),
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
]),
}
'''
dataload
Downloading: "https://download.pytorch.org/models/resnet18-f37072fd.pth" to /root/.cache/torch/hub/checkpoints/resnet18-f37072fd.pth
cp /root/.cache/torch/hub/checkpoints/resnet18-f37072fd.pth ~/.cache/torch/hub/checkpoints/resnet18-f37072fd.pth
'''
data_dir='train_cls/23_0421_text_cls2'
# data_dir='/data2/zengxingyu2/code/23_0420_cls_text/23_0421_text_cls2'
batch_size=8
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
image_datasets = {
x: datasets.ImageFolder(os.path.join(data_dir, x),
data_transforms[x])
for x in ['train', 'val']}
dataloaders = {
x: torch.utils.data.DataLoader(image_datasets[x], batch_size=batch_size,
shuffle=True, num_workers=4)
for x in ['train', 'val']}
dataset_sizes = {
x: len(image_datasets[x]) for x in ['train', 'val']}
class_names = image_datasets['train'].classes
def imshow(inp, title=None):
"""Display image for Tensor."""
inp = inp.numpy().transpose((1, 2, 0))
mean = np.array([0.485, 0.456, 0.406])
std = np.array([0.229, 0.224, 0.225])
inp = std * inp + mean
inp = np.clip(inp, 0, 1)
plt.imshow(inp)
if title is not None:
plt.title(title)
plt.pause(0.001) # pause a bit so that plots are updated
def train_model(model, criterion, optimizer, scheduler, num_epochs=25):
since = time.time()
best_model_wts = copy.deepcopy(model.state_dict())
best_acc = 0.0
for epoch in range(num_epochs):
print(f'Epoch {
epoch}/{
num_epochs - 1}')
print('-' * 10)
# Each epoch has a training and validation phase
for phase in ['train', 'val']:
if phase == 'train':
model.train() # Set model to training mode
else:
model.eval() # Set model to evaluate mode
running_loss = 0.0
running_corrects = 0
# Iterate over data.
for inputs, labels in dataloaders[phase]:
inputs = inputs.to(device)
labels = labels.to(device)
# zero the parameter gradients
optimizer.zero_grad()
# forward
# track history if only in train
with torch.set_grad_enabled(phase == 'train'):
outputs = model(inputs)
_, preds = torch.max(outputs, 1)
loss = criterion(outputs, labels)
# backward + optimize only if in training phase
if phase == 'train':
loss.backward()
optimizer.step()
# statistics
running_loss += loss.item() * inputs.size(0)
running_corrects += torch.sum(preds == labels.data)
if phase == 'train':
scheduler.step()
epoch_loss = running_loss / dataset_sizes[phase]
epoch_acc = running_corrects.double() / dataset_sizes[phase]
print(f'{
phase} Loss: {
epoch_loss:.4f} Acc: {
epoch_acc:.4f}')
# deep copy the model
if phase == 'val' and epoch_acc > best_acc:
best_acc = epoch_acc
best_model_wts = copy.deepcopy(model.state_dict())
torch.save(model, 'best_model_text_cls2.pth')
print()
time_elapsed = time.time() - since
print(f'Training complete in {
time_elapsed // 60:.0f}m {
time_elapsed % 60:.0f}s')
print(f'Best val Acc: {
best_acc:4f}')
# load best model weights
model.load_state_dict(best_model_wts)
return model
def visualize_model(model, num_images=6):
was_training = model.training
model.eval()
images_so_far = 0
fig = plt.figure()
with torch.no_grad():
for i, (inputs, labels) in enumerate(dataloaders['val']):
inputs = inputs.to(device)
labels = labels.to(device)
outputs = model(inputs)
_, preds = torch.max(outputs, 1)
for j in range(inputs.size()[0]):
images_so_far += 1
ax = plt.subplot(num_images//2, 2, images_so_far)
ax.axis('off')
ax.set_title(f'predicted: {
class_names[preds[j]]}')
imshow(inputs.cpu().data[j])
if images_so_far == num_images:
model.train(mode=was_training)
return
model.train(mode=was_training)
if __name__ == '__main__':
model_ft = models.resnet18(pretrained=True)
num_ftrs = model_ft.fc.in_features
# Here the size of each output sample is set to 2.
# Alternatively, it can be generalized to ``nn.Linear(num_ftrs, len(class_names))``.
model_ft.fc = nn.Linear(num_ftrs, 2)
model_ft = model_ft.to(device)
criterion = nn.CrossEntropyLoss()
# Observe that all parameters are being optimized
optimizer_ft = optim.SGD(model_ft.parameters(), lr=0.001, momentum=0.9)
# Decay LR by a factor of 0.1 every 7 epochs
exp_lr_scheduler = lr_scheduler.StepLR(optimizer_ft, step_size=7, gamma=0.1)
######################################################################
# Train and evaluate
# ^^^^^^^^^^^^^^^^^^
#
# It should take around 15-25 min on CPU. On GPU though, it takes less than a
# minute.
#
model_ft = train_model(model_ft, criterion, optimizer_ft, exp_lr_scheduler,
num_epochs=25)
torch.save(model_ft, 'best_model_text_cls2.pth')
# visualize_model(model_ft)