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PyTorch怎么实现图像识别

发表于:2024-11-26 作者:千家信息网编辑
千家信息网最后更新 2024年11月26日,这篇文章主要介绍"PyTorch怎么实现图像识别",在日常操作中,相信很多人在PyTorch怎么实现图像识别问题上存在疑惑,小编查阅了各式资料,整理出简单好用的操作方法,希望对大家解答"PyTorch
千家信息网最后更新 2024年11月26日PyTorch怎么实现图像识别

这篇文章主要介绍"PyTorch怎么实现图像识别",在日常操作中,相信很多人在PyTorch怎么实现图像识别问题上存在疑惑,小编查阅了各式资料,整理出简单好用的操作方法,希望对大家解答"PyTorch怎么实现图像识别"的疑惑有所帮助!接下来,请跟着小编一起来学习吧!

    概述

    今天我们要来做一个进阶的花分类问题. 不同于之前做过的鸢尾花, 这次我们会分析 102 中不同的花. 是不是很上头呀.

    预处理

    导包

    常规操作, 没什么好解释的. 缺模块的同学自行pip -install.

    import numpy as npimport timefrom matplotlib import pyplot as pltimport jsonimport copyimport osimport torchfrom torch import nnfrom torch import optimfrom torchvision import transforms, models, datasets

    数据读取与预处理

    数据预处理部分:

    数据增强: torchvision 中 transforms 模块自带功能, 用于扩充数据样本

    数据预处理: torchvision 中 transforms 也帮我们实现好了

    数据分批: DataLoader 模块直接读取 batch 数据

    # ----------------1. 数据读取与预处理------------------# 路径data_dir = './flower_data/'train_dir = data_dir + '/train'valid_dir = data_dir + '/valid'# 制作数据源data_transforms = {    'train': transforms.Compose([transforms.RandomRotation(45),  #随机旋转,-45到45度之间随机选        transforms.CenterCrop(224),  #从中心开始裁剪        transforms.RandomHorizontalFlip(p=0.5),  #随机水平翻转 选择一个概率概率        transforms.RandomVerticalFlip(p=0.5),  #随机垂直翻转        transforms.ColorJitter(brightness=0.2, contrast=0.1, saturation=0.1, hue=0.1),  #参数1为亮度, 参数2为对比度,参数3为饱和度,参数4为色相        transforms.RandomGrayscale(p=0.025),  #概率转换成灰度率, 3通道就是R=G=B        transforms.ToTensor(),        transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])  #均值, 标准差    ]),    'valid': transforms.Compose([transforms.Resize(256),        transforms.CenterCrop(224),        transforms.ToTensor(),        transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])    ]),}batch_size = 8image_datasets = {x: datasets.ImageFolder(os.path.join(data_dir, x), data_transforms[x]) for x in ['train', 'valid']}dataloaders = {x: torch.utils.data.DataLoader(image_datasets[x], batch_size=batch_size, shuffle=True) for x in ['train', 'valid']}dataset_sizes = {x: len(image_datasets[x]) for x in ['train', 'valid']}class_names = image_datasets['train'].classes# 调试输出print(image_datasets)print(dataloaders)print(dataset_sizes)print(class_names)# 读取标签对应的实际名字with open('cat_to_name.json', 'r') as f:    cat_to_name = json.load(f)print(cat_to_name)输出结果:{'train': Dataset ImageFolder    Number of datapoints: 6552    Root location: ./flower_data/train    StandardTransformTransform: Compose(               RandomRotation(degrees=(-45, 45), resample=False, expand=False)               CenterCrop(size=(224, 224))               RandomHorizontalFlip(p=0.5)               RandomVerticalFlip(p=0.5)               ColorJitter(brightness=[0.8, 1.2], contrast=[0.9, 1.1], saturation=[0.9, 1.1], hue=[-0.1, 0.1])               RandomGrayscale(p=0.025)               ToTensor()               Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225])           ), 'valid': Dataset ImageFolder    Number of datapoints: 818    Root location: ./flower_data/valid    StandardTransformTransform: Compose(               Resize(size=256, interpolation=PIL.Image.BILINEAR)               CenterCrop(size=(224, 224))               ToTensor()               Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225])           )}{'train': , 'valid': }{'train': 6552, 'valid': 818}['1', '10', '100', '101', '102', '11', '12', '13', '14', '15', '16', '17', '18', '19', '2', '20', '21', '22', '23', '24', '25', '26', '27', '28', '29', '3', '30', '31', '32', '33', '34', '35', '36', '37', '38', '39', '4', '40', '41', '42', '43', '44', '45', '46', '47', '48', '49', '5', '50', '51', '52', '53', '54', '55', '56', '57', '58', '59', '6', '60', '61', '62', '63', '64', '65', '66', '67', '68', '69', '7', '70', '71', '72', '73', '74', '75', '76', '77', '78', '79', '8', '80', '81', '82', '83', '84', '85', '86', '87', '88', '89', '9', '90', '91', '92', '93', '94', '95', '96', '97', '98', '99']{'21': 'fire lily', '3': 'canterbury bells', '45': 'bolero deep blue', '1': 'pink primrose', '34': 'mexican aster', '27': 'prince of wales feathers', '7': 'moon orchid', '16': 'globe-flower', '25': 'grape hyacinth', '26': 'corn poppy', '79': 'toad lily', '39': 'siam tulip', '24': 'red ginger', '67': 'spring crocus', '35': 'alpine sea holly', '32': 'garden phlox', '10': 'globe thistle', '6': 'tiger lily', '93': 'ball moss', '33': 'love in the mist', '9': 'monkshood', '102': 'blackberry lily', '14': 'spear thistle', '19': 'balloon flower', '100': 'blanket flower', '13': 'king protea', '49': 'oxeye daisy', '15': 'yellow iris', '61': 'cautleya spicata', '31': 'carnation', '64': 'silverbush', '68': 'bearded iris', '63': 'black-eyed susan', '69': 'windflower', '62': 'japanese anemone', '20': 'giant white arum lily', '38': 'great masterwort', '4': 'sweet pea', '86': 'tree mallow', '101': 'trumpet creeper', '42': 'daffodil', '22': 'pincushion flower', '2': 'hard-leaved pocket orchid', '54': 'sunflower', '66': 'osteospermum', '70': 'tree poppy', '85': 'desert-rose', '99': 'bromelia', '87': 'magnolia', '5': 'english marigold', '92': 'bee balm', '28': 'stemless gentian', '97': 'mallow', '57': 'gaura', '40': 'lenten rose', '47': 'marigold', '59': 'orange dahlia', '48': 'buttercup', '55': 'pelargonium', '36': 'ruby-lipped cattleya', '91': 'hippeastrum', '29': 'artichoke', '71': 'gazania', '90': 'canna lily', '18': 'peruvian lily', '98': 'mexican petunia', '8': 'bird of paradise', '30': 'sweet william', '17': 'purple coneflower', '52': 'wild pansy', '84': 'columbine', '12': "colt's foot", '11': 'snapdragon', '96': 'camellia', '23': 'fritillary', '50': 'common dandelion', '44': 'poinsettia', '53': 'primula', '72': 'azalea', '65': 'californian poppy', '80': 'anthurium', '76': 'morning glory', '37': 'cape flower', '56': 'bishop of llandaff', '60': 'pink-yellow dahlia', '82': 'clematis', '58': 'geranium', '75': 'thorn apple', '41': 'barbeton daisy', '95': 'bougainvillea', '43': 'sword lily', '83': 'hibiscus', '78': 'lotus lotus', '88': 'cyclamen', '94': 'foxglove', '81': 'frangipani', '74': 'rose', '89': 'watercress', '73': 'water lily', '46': 'wallflower', '77': 'passion flower', '51': 'petunia'}

    数据可视化

    虽然我也不知道这些都是什么花, 但是还是一起来看一下. 有知道的大佬可以评论区留个言.

    # ----------------2. 展示下数据------------------def im_convert(tensor):    """ 展示数据"""    image = tensor.to("cpu").clone().detach()    image = image.numpy().squeeze()    image = image.transpose(1, 2, 0)    image = image * np.array((0.229, 0.224, 0.225)) + np.array((0.485, 0.456, 0.406))    image = image.clip(0, 1)    return imagedef im_convert(tensor):    """ 展示数据"""    image = tensor.to("cpu").clone().detach()    image = image.numpy().squeeze()    image = image.transpose(1, 2, 0)    image = image * np.array((0.229, 0.224, 0.225)) + np.array((0.485, 0.456, 0.406))    image = image.clip(0, 1)    return imagefig=plt.figure(figsize=(20, 12))columns = 4rows = 2dataiter = iter(dataloaders['valid'])inputs, classes = dataiter.next()for idx in range (columns*rows):    ax = fig.add_subplot(rows, columns, idx+1, xticks=[], yticks=[])    ax.set_title(cat_to_name[str(int(class_names[classes[idx]]))])    plt.imshow(im_convert(inputs[idx]))plt.show()

    输出结果:

    主体

    加载参数

    # ----------------3. 加载models中提供的模型------------------# 直接使用训练好的权重当做初始化参数model_name = "resnet"  # 可选的比较多 ['resnet', 'alexnet', 'vgg', 'squeezenet', 'densenet', 'inception']# 是否使用人家训练好的特征来做feature_extract = True# 是否使用GPU训练train_on_gpu = torch.cuda.is_available()if not train_on_gpu:    print('CUDA is not available.  Training on CPU ...')else:    print('CUDA is not available.  Training on CPU ...')device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")def set_parameter_requires_grad(model, feature_extracting):    if feature_extracting:        for param in model.parameters():            param.requires_grad = Falsemodel_ft = models.resnet152()print(model_ft)输出结果:CUDA is not available.  Training on CPU ...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)    )    (4): 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)    )    (5): 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)    )    (6): 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)    )    (7): 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)    )    (6): 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)    )    (7): 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)    )    (8): 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)    )    (9): 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)    )    (10): 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)    )    (11): 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)    )    (12): 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)    )    (13): 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)    )    (14): 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)    )    (15): 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)    )    (16): 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)    )    (17): 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)    )    (18): 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)    )    (19): 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)    )    (20): 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)    )    (21): 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)    )    (22): 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)    )    (23): 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)    )    (24): 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)    )    (25): 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)    )    (26): 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)    )    (27): 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)    )    (28): 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)    )    (29): 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)    )    (30): 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)    )    (31): 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)    )    (32): 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)    )    (33): 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)    )    (34): 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)    )    (35): 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))

    建立模型

    # ----------------4. 参考PyTorch官网例子------------------def initialize_model(model_name, num_classes, feature_extract, use_pretrained=True):    # 选择合适的模型,不同模型的初始化方法稍微有点区别    model_ft = None    input_size = 0    if model_name == "resnet":        """ Resnet152        """        model_ft = models.resnet152(pretrained=use_pretrained)        set_parameter_requires_grad(model_ft, feature_extract)        num_ftrs = model_ft.fc.in_features        model_ft.fc = nn.Sequential(nn.Linear(num_ftrs, 102),                                   nn.LogSoftmax(dim=1))        input_size = 224    elif model_name == "alexnet":        """ Alexnet        """        model_ft = models.alexnet(pretrained=use_pretrained)        set_parameter_requires_grad(model_ft, feature_extract)        num_ftrs = model_ft.classifier[6].in_features        model_ft.classifier[6] = nn.Linear(num_ftrs,num_classes)        input_size = 224    elif model_name == "vgg":        """ VGG11_bn        """        model_ft = models.vgg16(pretrained=use_pretrained)        set_parameter_requires_grad(model_ft, feature_extract)        num_ftrs = model_ft.classifier[6].in_features        model_ft.classifier[6] = nn.Linear(num_ftrs,num_classes)        input_size = 224    elif model_name == "squeezenet":        """ Squeezenet        """        model_ft = models.squeezenet1_0(pretrained=use_pretrained)        set_parameter_requires_grad(model_ft, feature_extract)        model_ft.classifier[1] = nn.Conv2d(512, num_classes, kernel_size=(1,1), stride=(1,1))        model_ft.num_classes = num_classes        input_size = 224    elif model_name == "densenet":        """ Densenet        """        model_ft = models.densenet121(pretrained=use_pretrained)        set_parameter_requires_grad(model_ft, feature_extract)        num_ftrs = model_ft.classifier.in_features        model_ft.classifier = nn.Linear(num_ftrs, num_classes)        input_size = 224    elif model_name == "inception":        """ Inception v3        Be careful, expects (299,299) sized images and has auxiliary output        """        model_ft = models.inception_v3(pretrained=use_pretrained)        set_parameter_requires_grad(model_ft, feature_extract)        # Handle the auxilary net        num_ftrs = model_ft.AuxLogits.fc.in_features        model_ft.AuxLogits.fc = nn.Linear(num_ftrs, num_classes)        # Handle the primary net        num_ftrs = model_ft.fc.in_features        model_ft.fc = nn.Linear(num_ftrs,num_classes)        input_size = 299    else:        print("Invalid model name, exiting...")        exit()    return model_ft, input_size

    设置哪些层需要训练

    # ----------------5. 设置哪些层需要训练------------------model_ft, input_size = initialize_model(model_name, 102, feature_extract, use_pretrained=True)# GPU计算model_ft = model_ft.to(device)# 模型保存filename='checkpoint.pth'# 是否训练所有层params_to_update = model_ft.parameters()print("Params to learn:")if feature_extract:    params_to_update = []    for name,param in model_ft.named_parameters():        if param.requires_grad == True:            params_to_update.append(param)            print("\t",name)else:    for name,param in model_ft.named_parameters():        if param.requires_grad == True:            print("\t",name)

    优化器设置

    # ----------------6. 优化器设置------------------# 优化器设置optimizer_ft = optim.Adam(params_to_update, lr=1e-2)scheduler = optim.lr_scheduler.StepLR(optimizer_ft, step_size=7, gamma=0.1)  # 学习率每7个epoch衰减成原来的1/10# 最后一层已经LogSoftmax()了,所以不能nn.CrossEntropyLoss()来计算了# nn.CrossEntropyLoss()相当于logSoftmax()和nn.NLLLoss()整合criterion = nn.NLLLoss()

    训练模块

    # ----------------7. 训练模块------------------def train_model(model, dataloaders, criterion, optimizer, num_epochs=25, is_inception=False, filename=filename):    since = time.time()    best_acc = 0    """    checkpoint = torch.load(filename)    best_acc = checkpoint['best_acc']    model.load_state_dict(checkpoint['state_dict'])    optimizer.load_state_dict(checkpoint['optimizer'])    model.class_to_idx = checkpoint['mapping']    """    model.to(device)    val_acc_history = []    train_acc_history = []    train_losses = []    valid_losses = []    LRs = [optimizer.param_groups[0]['lr']]    best_model_wts = copy.deepcopy(model.state_dict())    for epoch in range(num_epochs):        print('Epoch {}/{}'.format(epoch, num_epochs - 1))        print('-' * 10)        # 训练和验证        for phase in ['train', 'valid']:            if phase == 'train':                model.train()  # 训练            else:                model.eval()  # 验证            running_loss = 0.0            running_corrects = 0            # 把数据都取个遍            for inputs, labels in dataloaders[phase]:                inputs = inputs.to(device)                labels = labels.to(device)                # 清零                optimizer.zero_grad()                # 只有训练的时候计算和更新梯度                with torch.set_grad_enabled(phase == 'train'):                    if is_inception and phase == 'train':                        outputs, aux_outputs = model(inputs)                        loss1 = criterion(outputs, labels)                        loss2 = criterion(aux_outputs, labels)                        loss = loss1 + 0.4 * loss2                    else:  # resnet执行的是这里                        outputs = model(inputs)                        loss = criterion(outputs, labels)                    _, preds = torch.max(outputs, 1)                    # 训练阶段更新权重                    if phase == 'train':                        loss.backward()                        optimizer.step()                # 计算损失                running_loss += loss.item() * inputs.size(0)                running_corrects += torch.sum(preds == labels.data)            epoch_loss = running_loss / len(dataloaders[phase].dataset)            epoch_acc = running_corrects.double() / len(dataloaders[phase].dataset)            time_elapsed = time.time() - since            print('Time elapsed {:.0f}m {:.0f}s'.format(time_elapsed // 60, time_elapsed % 60))            print('{} Loss: {:.4f} Acc: {:.4f}'.format(phase, epoch_loss, epoch_acc))            # 得到最好那次的模型            if phase == 'valid' and epoch_acc > best_acc:                best_acc = epoch_acc                best_model_wts = copy.deepcopy(model.state_dict())                state = {                    'state_dict': model.state_dict(),                    'best_acc': best_acc,                    'optimizer': optimizer.state_dict(),                }                torch.save(state, filename)            if phase == 'valid':                val_acc_history.append(epoch_acc)                valid_losses.append(epoch_loss)                scheduler.step(epoch_loss)            if phase == 'train':                train_acc_history.append(epoch_acc)                train_losses.append(epoch_loss)        print('Optimizer learning rate : {:.7f}'.format(optimizer.param_groups[0]['lr']))        LRs.append(optimizer.param_groups[0]['lr'])        print()    time_elapsed = time.time() - since    print('Training complete in {:.0f}m {:.0f}s'.format(time_elapsed // 60, time_elapsed % 60))    print('Best val Acc: {:4f}'.format(best_acc))    # 训练完后用最好的一次当做模型最终的结果    model.load_state_dict(best_model_wts)    return model, val_acc_history, train_acc_history, valid_losses, train_losses, LRs

    开始训练

    # ----------------8. 开始训练------------------# 训练model_ft, val_acc_history, train_acc_history, valid_losses, train_losses, LRs  = \    train_model(model_ft, dataloaders, criterion, optimizer_ft, num_epochs=20, is_inception=(model_name=="inception"))# 再继续训练所有层for param in model_ft.parameters():    param.requires_grad = True# 再继续训练所有的参数,学习率调小一点optimizer = optim.Adam(params_to_update, lr=1e-4)scheduler = optim.lr_scheduler.StepLR(optimizer_ft, step_size=7, gamma=0.1)# 损失函数criterion = nn.NLLLoss()# Load the checkpointcheckpoint = torch.load(filename)best_acc = checkpoint['best_acc']model_ft.load_state_dict(checkpoint['state_dict'])optimizer.load_state_dict(checkpoint['optimizer'])#model_ft.class_to_idx = checkpoint['mapping']model_ft, val_acc_history, train_acc_history, valid_losses, train_losses, LRs  = train_model(model_ft, dataloaders, criterion, optimizer, num_epochs=10, is_inception=(model_name=="inception"))输出结果:Epoch 0/9----------Time elapsed 3m 8strain Loss: 1.8128 Acc: 0.8065Time elapsed 3m 17svalid Loss: 4.6786 Acc: 0.6993Optimizer learning rate : 0.0010000Epoch 1/9----------Time elapsed 6m 26strain Loss: 1.5370 Acc: 0.8268Time elapsed 6m 34svalid Loss: 4.3483 Acc: 0.7017Optimizer learning rate : 0.0010000Epoch 2/9----------Time elapsed 9m 44strain Loss: 1.3812 Acc: 0.8367Time elapsed 9m 52svalid Loss: 4.0840 Acc: 0.7127Optimizer learning rate : 0.0010000Epoch 3/9----------Time elapsed 13m 2strain Loss: 1.4777 Acc: 0.8312Time elapsed 13m 10svalid Loss: 4.2493 Acc: 0.7078Optimizer learning rate : 0.0010000Epoch 4/9----------Time elapsed 16m 22strain Loss: 1.3351 Acc: 0.8434Time elapsed 16m 31svalid Loss: 3.6103 Acc: 0.7396Optimizer learning rate : 0.0010000Epoch 5/9----------Time elapsed 19m 42strain Loss: 1.2934 Acc: 0.8466Time elapsed 19m 51svalid Loss: 3.3350 Acc: 0.7494Optimizer learning rate : 0.0010000Epoch 6/9----------Time elapsed 23m 2strain Loss: 1.3289 Acc: 0.8379Time elapsed 23m 11svalid Loss: 3.9728 Acc: 0.7164Optimizer learning rate : 0.0010000Epoch 7/9----------Time elapsed 26m 22strain Loss: 1.3739 Acc: 0.8321Time elapsed 26m 31svalid Loss: 3.7483 Acc: 0.7237Optimizer learning rate : 0.0010000Epoch 8/9----------Time elapsed 29m 43strain Loss: 1.2110 Acc: 0.8495Time elapsed 29m 52svalid Loss: 3.7712 Acc: 0.7164Optimizer learning rate : 0.0010000Epoch 9/9----------Time elapsed 33m 2strain Loss: 1.2643 Acc: 0.8452Time elapsed 33m 11svalid Loss: 3.7012 Acc: 0.7311Optimizer learning rate : 0.0010000Training complete in 33m 11sBest val Acc: 0.749389

    测试

    测试网络效果

    # ----------------9. 测试网络效果------------------probs, classes = predict(image_path, model)print(probs)print(classes)输出结果:[ 0.01558163  0.01541934  0.01452626  0.01443549  0.01407339]['70', '3', '45', '62', '55']

    测试训练好的模型

    # ----------------10. 测试训练好的模型------------------model_ft, input_size = initialize_model(model_name, 102, feature_extract, use_pretrained=True)# GPU模式model_ft = model_ft.to(device)# 保存文件的名字filename = 'seriouscheckpoint.pth'# 加载模型checkpoint = torch.load(filename)best_acc = checkpoint['best_acc']model_ft.load_state_dict(checkpoint['state_dict'])

    测试数据预处理

    注意:

    • 测试数据处理方法需要跟训练时一致才可以

    • crop 操作的目的是保证输入的大小是一致的

    • 标准化也是必须的, 用跟训练数据相同的 mean 和 std

    • 训练数据是在 0~1 上进行标准化, 所以测试数据也需要先归一化

    • PyTorch 中的颜色是第一个维度, 跟很多工具包都不一样, 需要转换

    # ----------------11. 测试数据预处理------------------def process_image(image_path):    # 读取测试数据    img = Image.open(image_path)    # Resize,thumbnail方法只能进行缩小,所以进行了判断    if img.size[0] > img.size[1]:        img.thumbnail((10000, 256))    else:        img.thumbnail((256, 10000))    # Crop操作    left_margin = (img.width - 224) / 2    bottom_margin = (img.height - 224) / 2    right_margin = left_margin + 224    top_margin = bottom_margin + 224    img = img.crop((left_margin, bottom_margin, right_margin,                    top_margin))    # 相同的预处理方法    img = np.array(img) / 255    mean = np.array([0.485, 0.456, 0.406])  # provided mean    std = np.array([0.229, 0.224, 0.225])  # provided std    img = (img - mean) / std    # 注意颜色通道应该放在第一个位置    img = img.transpose((2, 0, 1))    return imgdef imshow(image, ax=None, title=None):    """展示数据"""    if ax is None:        fig, ax = plt.subplots()    # 颜色通道还原    image = np.array(image).transpose((1, 2, 0))    # 预处理还原    mean = np.array([0.485, 0.456, 0.406])    std = np.array([0.229, 0.224, 0.225])    image = std * image + mean    image = np.clip(image, 0, 1)    ax.imshow(image)    ax.set_title(title)    return aximage_path = 'image_06621.jpg'img = process_image(image_path)imshow(img)# 得到一个batch的测试数据dataiter = iter(dataloaders['valid'])images, labels = dataiter.next()model_ft.eval()if train_on_gpu:    output = model_ft(images.cuda())else:    output = model_ft(images)_, preds_tensor = torch.max(output, 1)preds = np.squeeze(preds_tensor.numpy()) if not train_on_gpu else np.squeeze(preds_tensor.cpu().numpy())

    展示预测结果

    # ----------------12. 展示预测结果------------------fig=plt.figure(figsize=(20, 20))columns =4rows = 2for idx in range (columns*rows):    ax = fig.add_subplot(rows, columns, idx+1, xticks=[], yticks=[])    plt.imshow(im_convert(images[idx]))    ax.set_title("{} ({})".format(cat_to_name[str(preds[idx])], cat_to_name[str(labels[idx].item())]),                 color=("green" if cat_to_name[str(preds[idx])]==cat_to_name[str(labels[idx].item())] else "red"))plt.show()

    输出结果:

    到此,关于"PyTorch怎么实现图像识别"的学习就结束了,希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习,快去试试吧!若想继续学习更多相关知识,请继续关注网站,小编会继续努力为大家带来更多实用的文章!

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