基于ResNet模型微调的自定义图像数据分类

# Import necessary packages.
import torch
import torch.nn as nn
from torchvision import datasets, models, transforms
from torchsummary import summary

import numpy as np
import matplotlib.pyplot as plt
from PIL import Image
import time
import os

# Device configuration.
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
device

device(type='cuda')

# Hyper-parameters setting.
batch_size = 256
num_epochs = 30

# Image preprocessing modules.
image_transforms = {
    'train': transforms.Compose([transforms.RandomResizedCrop(size=256, scale=(0.8, 1.0)),
                                 transforms.RandomRotation(degrees=15),
                                 transforms.RandomHorizontalFlip(),
                                 transforms.CenterCrop(size=224),
                                 transforms.ToTensor(),
                                 transforms.Normalize([0.485, 0.456, 0.406],
                                                      [0.229, 0.224, 0.225])]),
    
    'valid':transforms.Compose([transforms.Resize(size=256),
                                transforms.CenterCrop(size=224),
                                transforms.ToTensor(),
                                transforms.Normalize([0.485, 0.456, 0.406],
                                                     [0.229, 0.224, 0.225])]),

    'test':transforms.Compose([transforms.Resize(size=256),
                               transforms.CenterCrop(size=224),
                               transforms.ToTensor(),
                               transforms.Normalize([0.485, 0.456, 0.406],
                                                    [0.229, 0.224, 0.225])])                                                     
}

# Load the Subset-datasets of Caltech 256.
dataset = './Datasets/'

# Set the dataset directory.
train_directory = os.path.join(dataset, 'train')
valid_directory = os.path.join(dataset, 'valid')
test_directory = os.path.join(dataset, 'test')

# Number of classes.
# num_classes = len(os.listdir(valid_directory))
# print(num_classes)  # num_classes is 10.

# Load Data from folders.
data = {
    'train':datasets.ImageFolder(root=train_directory,
                                 transform=image_transforms['train']),
    'valid':datasets.ImageFolder(root=valid_directory,
                                 transform=image_transforms['valid']),
    'test': datasets.ImageFolder(root=test_directory,
                                 transform=image_transforms['test'])                                                                 
}

# Define the DataLoader.
train_data_loader = torch.utils.data.DataLoader(data['train'],
                                                batch_size=batch_size,
                                                shuffle=True)
valid_data_loader = torch.utils.data.DataLoader(data['valid'],
                                                batch_size=batch_size,
                                                shuffle=True)
test_data_loader = torch.utils.data.DataLoader(data['test'],
                                               batch_size=batch_size,
                                               shuffle=False)

# Load pretrained ResNet50 Model.
resnet50 = models.resnet50(pretrained=True).to(device)
print(resnet50)

/home/wsl_ubuntu/anaconda3/envs/xy_trans/lib/python3.8/site-packages/torchvision/models/_utils.py:208: UserWarning: The parameter 'pretrained' is deprecated since 0.13 and may be removed in the future, please use 'weights' instead.
  warnings.warn(
/home/wsl_ubuntu/anaconda3/envs/xy_trans/lib/python3.8/site-packages/torchvision/models/_utils.py:223: UserWarning: Arguments other than a weight enum or `None` for 'weights' are deprecated since 0.13 and may be removed in the future. The current behavior is equivalent to passing `weights=ResNet50_Weights.IMAGENET1K_V1`. You can also use `weights=ResNet50_Weights.DEFAULT` to get the most up-to-date weights.
  warnings.warn(msg)


ResNet(
  (conv1): Conv2d(3, 64, kernel_size=(7, 7), stride=(2, 2), padding=(3, 3), bias=False)
  (bn1): BatchNorm2d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
  (relu): ReLU(inplace=True)
  (maxpool): MaxPool2d(kernel_size=3, stride=2, padding=1, dilation=1, ceil_mode=False)
  (layer1): Sequential(
    (0): Bottleneck(
      (conv1): Conv2d(64, 64, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(64, 64, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(64, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
      (downsample): Sequential(
        (0): Conv2d(64, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
        (1): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      )
    )
    (1): Bottleneck(
      (conv1): Conv2d(256, 64, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(64, 64, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(64, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
    (2): Bottleneck(
      (conv1): Conv2d(256, 64, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(64, 64, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(64, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(64, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
  )
  (layer2): Sequential(
    (0): Bottleneck(
      (conv1): Conv2d(256, 128, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(128, 128, kernel_size=(3, 3), stride=(2, 2), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(128, 512, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
      (downsample): Sequential(
        (0): Conv2d(256, 512, kernel_size=(1, 1), stride=(2, 2), bias=False)
        (1): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      )
    )
    (1): Bottleneck(
      (conv1): Conv2d(512, 128, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(128, 128, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(128, 512, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
    (2): Bottleneck(
      (conv1): Conv2d(512, 128, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(128, 128, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(128, 512, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
    (3): Bottleneck(
      (conv1): Conv2d(512, 128, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(128, 128, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(128, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(128, 512, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
  )
  (layer3): Sequential(
    (0): Bottleneck(
      (conv1): Conv2d(512, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(256, 256, kernel_size=(3, 3), stride=(2, 2), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(256, 1024, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(1024, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
      (downsample): Sequential(
        (0): Conv2d(512, 1024, kernel_size=(1, 1), stride=(2, 2), bias=False)
        (1): BatchNorm2d(1024, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      )
    )
    (1): Bottleneck(
      (conv1): Conv2d(1024, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(256, 1024, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(1024, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
    (2): Bottleneck(
      (conv1): Conv2d(1024, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(256, 1024, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(1024, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
    (3): Bottleneck(
      (conv1): Conv2d(1024, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(256, 1024, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(1024, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
    (4): Bottleneck(
      (conv1): Conv2d(1024, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(256, 1024, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(1024, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
    (5): Bottleneck(
      (conv1): Conv2d(1024, 256, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(256, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(256, 1024, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(1024, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
  )
  (layer4): Sequential(
    (0): Bottleneck(
      (conv1): Conv2d(1024, 512, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(512, 512, kernel_size=(3, 3), stride=(2, 2), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(512, 2048, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(2048, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
      (downsample): Sequential(
        (0): Conv2d(1024, 2048, kernel_size=(1, 1), stride=(2, 2), bias=False)
        (1): BatchNorm2d(2048, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      )
    )
    (1): Bottleneck(
      (conv1): Conv2d(2048, 512, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(512, 2048, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(2048, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
    (2): Bottleneck(
      (conv1): Conv2d(2048, 512, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn1): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv2): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1), bias=False)
      (bn2): BatchNorm2d(512, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (conv3): Conv2d(512, 2048, kernel_size=(1, 1), stride=(1, 1), bias=False)
      (bn3): BatchNorm2d(2048, eps=1e-05, momentum=0.1, affine=True, track_running_stats=True)
      (relu): ReLU(inplace=True)
    )
  )
  (avgpool): AdaptiveAvgPool2d(output_size=(1, 1))
  (fc): Linear(in_features=2048, out_features=1000, bias=True)
)

# Freeze model parameters, make a preparation for fine-tuning.
for param in resnet50.parameters():
    param.requires_grad = False

# Change the final layer of ResNet50 for Transfer Learning.
fc_inputs = resnet50.fc.in_features

resnet50.fc = nn.Sequential(nn.Linear(fc_inputs, 256),
                            nn.ReLU(),
                            nn.Dropout(0.4),
                            nn.Linear(256, len(os.listdir(valid_directory))),     # Related to the 10 outputs classes.
                            nn.LogSoftmax(dim=1))   # For using NLLLoss()   

# Convert model to be used on GPU.
resnet50 = resnet50.to(device)

# Loss and optimizer.
criterion = nn.NLLLoss()
optimizer = torch.optim.Adam(resnet50.parameters())

# Define Train & Validate Utils Function.
def train_and_validate(model, loss_criterion, optimizer, epochs=25):
    """
    Function used to train and validate.
    Parameters:
        :param model: Model to train and validate.
        :param loss_criterion: Loss Criterion to minimize.
        :param optimizer: Optimizer for computing gradients.
        :param epochs: Number of epochs (default=25)
    """
    
    history = []
    best_loss = 100000.0
    best_epoch = None

    for epoch in range(epochs):
        epoch_start = time.time()
        print("Epoch: {}/{}".format(epoch+1, epochs))

        # Set to training mode.
        model.train()

        # Loss and Accuracy within the epoch.
        train_loss = 0.0
        train_acc = 0.0

        valid_loss = 0.0
        valid_acc = 0.0

        for _, (inputs, labels) in enumerate(train_data_loader):
            # Move the data pair to device.
            inputs = inputs.to(device)
            labels = labels.to(device)

            # Forward pass and calculate loss.
            outputs = model(inputs)
            loss = loss_criterion(outputs, labels)

            # Backward and optimize.
            optimizer.zero_grad()
            loss.backward()
            optimizer.step()

            # Compute the total loss for the batch and add it to train_loss.
            train_loss += loss.item() * inputs.size(0)

            # Compute the accuracy.
            _, predictions = torch.max(outputs.data, 1)
            correct_counts = predictions.eq(labels.data.view_as(predictions))

            # Convert correct_counts to float and then compute the mean.
            acc = torch.mean(correct_counts.type(torch.FloatTensor))

            # Compute total accuracy in the whole batch and add to train_acc.
            train_acc += acc.item() * inputs.size(0)

            #print("Batch number: {:03d}, Training: Loss: {:.4f}, Accuracy: {:.4f}".format(i, loss.item(), acc.item()))

        # Validation - No gradient tracking needed.
        with torch.no_grad():

            # Set to evaluation mode.
            model.eval()

            # Validation loop.
            for _, (inputs, labels) in enumerate(valid_data_loader):
                inputs = inputs.to(device)
                labels = labels.to(device)

                # Forward pass - compute outputs on input data using the model
                outputs = model(inputs)

                # Compute loss
                loss = loss_criterion(outputs, labels)

                # Compute the total loss for the batch and add it to valid_loss
                valid_loss += loss.item() * inputs.size(0)

                # Calculate validation accuracy
                _, predictions = torch.max(outputs.data, 1)
                correct_counts = predictions.eq(labels.data.view_as(predictions))

                # Convert correct_counts to float and then compute the mean
                acc = torch.mean(correct_counts.type(torch.FloatTensor))

                # Compute total accuracy in the whole batch and add to valid_acc
                valid_acc += acc.item() * inputs.size(0)

                #print("Validation Batch number: {:03d}, Validation: Loss: {:.4f}, Accuracy: {:.4f}".format(j, loss.item(), acc.item()))
        if valid_loss < best_loss:
            best_loss = valid_loss
            best_epoch = epoch
        
        # Find average training loss and train accuracy.
        avg_train_loss = train_loss/len(data['train'])
        avg_train_acc = train_acc/len(data['train'])

        # Find average training loss and training accuracy.
        avg_valid_loss = valid_loss/len(data['valid'])
        avg_valid_acc = valid_acc/len(data['valid'])

        history.append([avg_train_loss, avg_valid_loss, avg_train_acc, avg_valid_acc])

        epoch_end = time.time()

        print("Epoch : {:03d}, Training: Loss - {:.4f}, Accuracy - {:.4f}%, \n\t\tValidation : Loss - {:.4f}, Accuracy - {:.4f}%, Time: {:.4f}s".format(epoch, avg_train_loss, avg_train_acc*100, avg_valid_loss, avg_valid_acc*100, epoch_end-epoch_start))
        
        # Save if the model has best accuracy till now
        torch.save(model, dataset+'_model_'+str(epoch)+'.pt')
            
    return model, history, best_epoch

# Print the model to be trained
summary(resnet50, input_size=(3, 224, 224), batch_size=batch_size, device='cuda')

# Train the model for 25 epochs
# num_epochs = 30
# trained_model, history, best_epoch = train_and_validate(resnet50, loss_func, optimizer, num_epochs)

# torch.save(history, dataset+'_history.pt')

=================================================================
Layer (type:depth-idx)                   Param #
=================================================================
├─Conv2d: 1-1                            (9,408)
├─BatchNorm2d: 1-2                       (128)
├─ReLU: 1-3                              --
├─MaxPool2d: 1-4                         --
├─Sequential: 1-5                        --
|    └─Bottleneck: 2-1                   --
|    |    └─Conv2d: 3-1                  (4,096)
|    |    └─BatchNorm2d: 3-2             (128)
|    |    └─Conv2d: 3-3                  (36,864)
|    |    └─BatchNorm2d: 3-4             (128)
|    |    └─Conv2d: 3-5                  (16,384)
|    |    └─BatchNorm2d: 3-6             (512)
|    |    └─ReLU: 3-7                    --
|    |    └─Sequential: 3-8              (16,896)
|    └─Bottleneck: 2-2                   --
|    |    └─Conv2d: 3-9                  (16,384)
|    |    └─BatchNorm2d: 3-10            (128)
|    |    └─Conv2d: 3-11                 (36,864)
|    |    └─BatchNorm2d: 3-12            (128)
|    |    └─Conv2d: 3-13                 (16,384)
|    |    └─BatchNorm2d: 3-14            (512)
|    |    └─ReLU: 3-15                   --
|    └─Bottleneck: 2-3                   --
|    |    └─Conv2d: 3-16                 (16,384)
|    |    └─BatchNorm2d: 3-17            (128)
|    |    └─Conv2d: 3-18                 (36,864)
|    |    └─BatchNorm2d: 3-19            (128)
|    |    └─Conv2d: 3-20                 (16,384)
|    |    └─BatchNorm2d: 3-21            (512)
|    |    └─ReLU: 3-22                   --
├─Sequential: 1-6                        --
|    └─Bottleneck: 2-4                   --
|    |    └─Conv2d: 3-23                 (32,768)
|    |    └─BatchNorm2d: 3-24            (256)
|    |    └─Conv2d: 3-25                 (147,456)
|    |    └─BatchNorm2d: 3-26            (256)
|    |    └─Conv2d: 3-27                 (65,536)
|    |    └─BatchNorm2d: 3-28            (1,024)
|    |    └─ReLU: 3-29                   --
|    |    └─Sequential: 3-30             (132,096)
|    └─Bottleneck: 2-5                   --
|    |    └─Conv2d: 3-31                 (65,536)
|    |    └─BatchNorm2d: 3-32            (256)
|    |    └─Conv2d: 3-33                 (147,456)
|    |    └─BatchNorm2d: 3-34            (256)
|    |    └─Conv2d: 3-35                 (65,536)
|    |    └─BatchNorm2d: 3-36            (1,024)
|    |    └─ReLU: 3-37                   --
|    └─Bottleneck: 2-6                   --
|    |    └─Conv2d: 3-38                 (65,536)
|    |    └─BatchNorm2d: 3-39            (256)
|    |    └─Conv2d: 3-40                 (147,456)
|    |    └─BatchNorm2d: 3-41            (256)
|    |    └─Conv2d: 3-42                 (65,536)
|    |    └─BatchNorm2d: 3-43            (1,024)
|    |    └─ReLU: 3-44                   --
|    └─Bottleneck: 2-7                   --
|    |    └─Conv2d: 3-45                 (65,536)
|    |    └─BatchNorm2d: 3-46            (256)
|    |    └─Conv2d: 3-47                 (147,456)
|    |    └─BatchNorm2d: 3-48            (256)
|    |    └─Conv2d: 3-49                 (65,536)
|    |    └─BatchNorm2d: 3-50            (1,024)
|    |    └─ReLU: 3-51                   --
├─Sequential: 1-7                        --
|    └─Bottleneck: 2-8                   --
|    |    └─Conv2d: 3-52                 (131,072)
|    |    └─BatchNorm2d: 3-53            (512)
|    |    └─Conv2d: 3-54                 (589,824)
|    |    └─BatchNorm2d: 3-55            (512)
|    |    └─Conv2d: 3-56                 (262,144)
|    |    └─BatchNorm2d: 3-57            (2,048)
|    |    └─ReLU: 3-58                   --
|    |    └─Sequential: 3-59             (526,336)
|    └─Bottleneck: 2-9                   --
|    |    └─Conv2d: 3-60                 (262,144)
|    |    └─BatchNorm2d: 3-61            (512)
|    |    └─Conv2d: 3-62                 (589,824)
|    |    └─BatchNorm2d: 3-63            (512)
|    |    └─Conv2d: 3-64                 (262,144)
|    |    └─BatchNorm2d: 3-65            (2,048)
|    |    └─ReLU: 3-66                   --
|    └─Bottleneck: 2-10                  --
|    |    └─Conv2d: 3-67                 (262,144)
|    |    └─BatchNorm2d: 3-68            (512)
|    |    └─Conv2d: 3-69                 (589,824)
|    |    └─BatchNorm2d: 3-70            (512)
|    |    └─Conv2d: 3-71                 (262,144)
|    |    └─BatchNorm2d: 3-72            (2,048)
|    |    └─ReLU: 3-73                   --
|    └─Bottleneck: 2-11                  --
|    |    └─Conv2d: 3-74                 (262,144)
|    |    └─BatchNorm2d: 3-75            (512)
|    |    └─Conv2d: 3-76                 (589,824)
|    |    └─BatchNorm2d: 3-77            (512)
|    |    └─Conv2d: 3-78                 (262,144)
|    |    └─BatchNorm2d: 3-79            (2,048)
|    |    └─ReLU: 3-80                   --
|    └─Bottleneck: 2-12                  --
|    |    └─Conv2d: 3-81                 (262,144)
|    |    └─BatchNorm2d: 3-82            (512)
|    |    └─Conv2d: 3-83                 (589,824)
|    |    └─BatchNorm2d: 3-84            (512)
|    |    └─Conv2d: 3-85                 (262,144)
|    |    └─BatchNorm2d: 3-86            (2,048)
|    |    └─ReLU: 3-87                   --
|    └─Bottleneck: 2-13                  --
|    |    └─Conv2d: 3-88                 (262,144)
|    |    └─BatchNorm2d: 3-89            (512)
|    |    └─Conv2d: 3-90                 (589,824)
|    |    └─BatchNorm2d: 3-91            (512)
|    |    └─Conv2d: 3-92                 (262,144)
|    |    └─BatchNorm2d: 3-93            (2,048)
|    |    └─ReLU: 3-94                   --
├─Sequential: 1-8                        --
|    └─Bottleneck: 2-14                  --
|    |    └─Conv2d: 3-95                 (524,288)
|    |    └─BatchNorm2d: 3-96            (1,024)
|    |    └─Conv2d: 3-97                 (2,359,296)
|    |    └─BatchNorm2d: 3-98            (1,024)
|    |    └─Conv2d: 3-99                 (1,048,576)
|    |    └─BatchNorm2d: 3-100           (4,096)
|    |    └─ReLU: 3-101                  --
|    |    └─Sequential: 3-102            (2,101,248)
|    └─Bottleneck: 2-15                  --
|    |    └─Conv2d: 3-103                (1,048,576)
|    |    └─BatchNorm2d: 3-104           (1,024)
|    |    └─Conv2d: 3-105                (2,359,296)
|    |    └─BatchNorm2d: 3-106           (1,024)
|    |    └─Conv2d: 3-107                (1,048,576)
|    |    └─BatchNorm2d: 3-108           (4,096)
|    |    └─ReLU: 3-109                  --
|    └─Bottleneck: 2-16                  --
|    |    └─Conv2d: 3-110                (1,048,576)
|    |    └─BatchNorm2d: 3-111           (1,024)
|    |    └─Conv2d: 3-112                (2,359,296)
|    |    └─BatchNorm2d: 3-113           (1,024)
|    |    └─Conv2d: 3-114                (1,048,576)
|    |    └─BatchNorm2d: 3-115           (4,096)
|    |    └─ReLU: 3-116                  --
├─AdaptiveAvgPool2d: 1-9                 --
├─Sequential: 1-10                       --
|    └─Linear: 2-17                      524,544
|    └─ReLU: 2-18                        --
|    └─Dropout: 2-19                     --
|    └─Linear: 2-20                      2,570
|    └─LogSoftmax: 2-21                  --
=================================================================
Total params: 24,035,146
Trainable params: 527,114
Non-trainable params: 23,508,032
=================================================================

# Train the model for 25 epochs
trained_model, history, best_epoch = train_and_validate(resnet50, criterion, optimizer, num_epochs)

torch.save(history, dataset+'_history.pt')

Epoch: 1/30
Epoch : 000, Training: Loss - 2.1844, Accuracy - 21.0000%, 
		Validation : Loss - 1.4458, Accuracy - 87.0000%, Time: 23.0077s
Epoch: 2/30
Epoch : 001, Training: Loss - 1.4131, Accuracy - 71.6667%, 
		Validation : Loss - 0.8001, Accuracy - 85.0000%, Time: 11.8903s
Epoch: 3/30
Epoch : 002, Training: Loss - 0.8666, Accuracy - 87.5000%, 
		Validation : Loss - 0.4689, Accuracy - 97.0000%, Time: 12.4398s
Epoch: 4/30
Epoch : 003, Training: Loss - 0.5742, Accuracy - 88.1667%, 
		Validation : Loss - 0.3205, Accuracy - 96.0000%, Time: 11.9200s
Epoch: 5/30
Epoch : 004, Training: Loss - 0.3776, Accuracy - 93.1667%, 
		Validation : Loss - 0.2615, Accuracy - 97.0000%, Time: 11.8079s
Epoch: 6/30
Epoch : 005, Training: Loss - 0.2893, Accuracy - 94.1667%, 
		Validation : Loss - 0.2209, Accuracy - 95.0000%, Time: 11.7730s
Epoch: 7/30
Epoch : 006, Training: Loss - 0.2247, Accuracy - 95.0000%, 
		Validation : Loss - 0.2052, Accuracy - 96.0000%, Time: 11.8106s
Epoch: 8/30
Epoch : 007, Training: Loss - 0.1790, Accuracy - 96.3333%, 
		Validation : Loss - 0.1859, Accuracy - 95.0000%, Time: 11.8970s
Epoch: 9/30
Epoch : 008, Training: Loss - 0.1688, Accuracy - 96.6667%, 
		Validation : Loss - 0.1819, Accuracy - 96.0000%, Time: 11.7606s
Epoch: 10/30
Epoch : 009, Training: Loss - 0.1302, Accuracy - 97.3333%, 
		Validation : Loss - 0.1788, Accuracy - 94.0000%, Time: 11.7755s
Epoch: 11/30
Epoch : 010, Training: Loss - 0.1205, Accuracy - 97.0000%, 
		Validation : Loss - 0.1410, Accuracy - 98.0000%, Time: 11.6803s
Epoch: 12/30
Epoch : 011, Training: Loss - 0.1158, Accuracy - 97.3333%, 
		Validation : Loss - 0.1378, Accuracy - 98.0000%, Time: 11.6497s
Epoch: 13/30
Epoch : 012, Training: Loss - 0.0967, Accuracy - 98.0000%, 
		Validation : Loss - 0.1727, Accuracy - 96.0000%, Time: 11.7946s
Epoch: 14/30
Epoch : 013, Training: Loss - 0.0874, Accuracy - 98.1667%, 
		Validation : Loss - 0.1780, Accuracy - 95.0000%, Time: 11.9912s
Epoch: 15/30
Epoch : 014, Training: Loss - 0.0901, Accuracy - 97.8333%, 
		Validation : Loss - 0.1570, Accuracy - 96.0000%, Time: 12.9568s
Epoch: 16/30
Epoch : 015, Training: Loss - 0.0746, Accuracy - 98.1667%, 
		Validation : Loss - 0.1415, Accuracy - 96.0000%, Time: 12.2158s
Epoch: 17/30
Epoch : 016, Training: Loss - 0.0719, Accuracy - 98.3333%, 
		Validation : Loss - 0.1419, Accuracy - 95.0000%, Time: 12.5166s
Epoch: 18/30
Epoch : 017, Training: Loss - 0.0780, Accuracy - 98.0000%, 
		Validation : Loss - 0.1261, Accuracy - 98.0000%, Time: 12.3080s
Epoch: 19/30
Epoch : 018, Training: Loss - 0.0710, Accuracy - 98.1667%, 
		Validation : Loss - 0.1370, Accuracy - 97.0000%, Time: 11.9036s
Epoch: 20/30
Epoch : 019, Training: Loss - 0.0686, Accuracy - 98.3333%, 
		Validation : Loss - 0.1563, Accuracy - 97.0000%, Time: 11.8692s
Epoch: 21/30
Epoch : 020, Training: Loss - 0.0649, Accuracy - 98.8333%, 
		Validation : Loss - 0.1606, Accuracy - 96.0000%, Time: 12.0231s
Epoch: 22/30
Epoch : 021, Training: Loss - 0.0528, Accuracy - 99.0000%, 
		Validation : Loss - 0.1435, Accuracy - 96.0000%, Time: 11.9158s
Epoch: 23/30
Epoch : 022, Training: Loss - 0.0606, Accuracy - 98.1667%, 
		Validation : Loss - 0.1376, Accuracy - 97.0000%, Time: 11.8283s
Epoch: 24/30
Epoch : 023, Training: Loss - 0.0606, Accuracy - 98.8333%, 
		Validation : Loss - 0.1445, Accuracy - 96.0000%, Time: 11.7824s
Epoch: 25/30
Epoch : 024, Training: Loss - 0.0530, Accuracy - 99.1667%, 
		Validation : Loss - 0.1682, Accuracy - 94.0000%, Time: 11.7249s
Epoch: 26/30
Epoch : 025, Training: Loss - 0.0528, Accuracy - 98.8333%, 
		Validation : Loss - 0.1614, Accuracy - 93.0000%, Time: 12.2925s
Epoch: 27/30
Epoch : 026, Training: Loss - 0.0583, Accuracy - 98.6667%, 
		Validation : Loss - 0.1518, Accuracy - 94.0000%, Time: 12.1458s
Epoch: 28/30
Epoch : 027, Training: Loss - 0.0407, Accuracy - 98.8333%, 
		Validation : Loss - 0.1408, Accuracy - 96.0000%, Time: 11.9303s
Epoch: 29/30
Epoch : 028, Training: Loss - 0.0671, Accuracy - 98.5000%, 
		Validation : Loss - 0.1508, Accuracy - 96.0000%, Time: 11.9089s
Epoch: 30/30
Epoch : 029, Training: Loss - 0.0443, Accuracy - 98.8333%, 
		Validation : Loss - 0.1763, Accuracy - 95.0000%, Time: 12.5318s

# Plot the learning curve.
history = np.array(history)
plt.plot(history[:, 0], color='red', marker='o')
plt.plot(history[:, 1], color='blue', marker='x')
plt.legend(['Tr Loss', 'Val Loss'])
plt.xlabel('Epoch Number')
plt.ylabel('Loss')
plt.ylim(0,1)
plt.savefig(dataset+'_loss_curve.png')
plt.show()

# Plot the learning curve.
history = np.array(history)
plt.plot(history[:, 2], color='red', marker='o')
plt.plot(history[:, -1], color='blue', marker='x')
plt.legend(['Tr Loss', 'Val Loss'])
plt.xlabel('Epoch Number')
plt.ylabel('Loss')
plt.ylim(0,1)
plt.savefig(dataset+'_loss_curve.png')
plt.show()

def computeTestSetAccuracy(model, loss_criterion):
    '''
    Function to compute the accuracy on the test set
    Parameters
        :param model: Model to test
        :param loss_criterion: Loss Criterion to minimize
    '''

    test_acc = 0.0
    test_loss = 0.0

    # Validation - No gradient tracking needed.
    with torch.no_grad():

        # Set to evaluation mode.
        model.eval()

        # Validation loop
        for j, (inputs, labels) in enumerate(test_data_loader):
            inputs = inputs.to(device)
            labels = labels.to(device)

            # Forward pass - compute outputs on input data using the model.
            outputs = model(inputs)

            # Compute loss
            loss = loss_criterion(outputs, labels)

            # Compute the total loss for the batch and add it to valid_loss.
            test_loss += loss.item() * inputs.size(0)

            # Calculate validation accuracy.
            ret, predictions = torch.max(outputs.data, 1)
            correct_counts = predictions.eq(labels.data.view_as(predictions))

            # Convert correct_counts to float and then compute the mean.
            acc = torch.mean(correct_counts.type(torch.FloatTensor))

            # Compute total accuracy in the whole batch and add to valid_acc.
            test_acc += acc.item() * inputs.size(0)

            print("Test Batch number: {:03d}, Test: Loss: {:.4f}, Accuracy: {:.4f}".format(j, loss.item(), acc.item()))

    # Find average test loss and test accuracy
    avg_test_loss = test_loss/len(data['test'])
    avg_test_acc = test_acc/len(data['test'])

    print("Test accuracy : " + str(avg_test_acc))

# Get a mapping of the indices to the class names, in order to see the output classes of the test images.
idx_to_class = {v: k for k, v in data['train'].class_to_idx.items()}
print(idx_to_class)

{0: 'bear', 1: 'chimp', 2: 'giraffe', 3: 'gorilla', 4: 'llama', 5: 'ostrich', 6: 'porcupine', 7: 'skunk', 8: 'triceratops', 9: 'zebra'}

def predict(model, test_image_name):
    '''
    Function to predict the class of a single test image
    Parameters
        :param model: Model to test
        :param test_image_name: Test image

    '''
    
    transform = image_transforms['test']


    test_image = Image.open(test_image_name)
    plt.imshow(test_image)
    
    test_image_tensor = transform(test_image)
    if torch.cuda.is_available():
        test_image_tensor = test_image_tensor.view(1, 3, 224, 224).cuda()
    else:
        test_image_tensor = test_image_tensor.view(1, 3, 224, 224)
    
    with torch.no_grad():
        model.eval()
        # Model outputs log probabilities.
        out = model(test_image_tensor)
        ps = torch.exp(out)

        topk, topclass = ps.topk(3, dim=1)
        cls = idx_to_class[topclass.cpu().numpy()[0][0]]
        score = topk.cpu().numpy()[0][0]

        for i in range(3):
            print("Predcition", i+1, ":", idx_to_class[topclass.cpu().numpy()[0][i]], ", Score: ", topk.cpu().numpy()[0][i])

# Test a particular model on a test image
# ! wget https://cdn.pixabay.com/photo/2018/10/01/12/28/skunk-3716043_1280.jpg -O skunk.jpg
model = torch.load("./Datasets/_model_{}.pt".format(best_epoch))
predict(model, './Datasets/skunk-3716043_1280.jpg')

# Load Data from folders
#computeTestSetAccuracy(model, loss_func)

Predcition 1 : skunk , Score:  0.99803644
Predcition 2 : porcupine , Score:  0.001755606
Predcition 3 : bear , Score:  8.1849976e-05