data = f['mask_1'][:]

这是一个 Python 代码片段，其中 f 是一个文件对象，'mask_1' 是该文件中的一个数据集名称，[:] 表示获取该数据集的所有值。具体来说，这段代码将 'mask_1' 数据集中的所有值赋给了变量 data。

相关问题

def get_CIFAR10_data(num_training=5000, num_validation=500, num_test=500): cifar10_dir = r'D:\daima\cifar-10-python\cifar-10-batches-py' X_train, y_train, X_test, y_test = load_CIFAR10(cifar10_dir) print(X_train.shape) mask = range(num_training, num_training + num_validation) X_val = X_train[mask] y_val = y_train[mask] mask = range(num_training) X_train = X_train[mask] y_train = y_train[mask] mask = range(num_test) X_test = X_test[mask] y_test = y_test[mask] mean_image = np.mean(X_train, axis=0) X_train -= mean_image X_val -= mean_image X_test -= mean_image X_train = X_train.transpose(0, 3, 1, 2).copy() X_val = X_val.transpose(0, 3, 1, 2).copy() X_test = X_test.transpose(0, 3, 1, 2).copy() return { 'X_train': X_train, 'y_train': y_train, 'X_val': X_val, 'y_val': y_val, 'X_test': X_test, 'y_test': y_test, }这是一个加载cifar10数据集的函数，如何修改使其能加载mnist数据集，不使用使用 TensorFlow

要加载MNIST数据集，可以使用以下代码：

import numpy as np
import gzip

def load_mnist(path, kind='train'):
    """Load MNIST data from `path`"""
    labels_path = f'{path}/{kind}-labels-idx1-ubyte.gz'
    images_path = f'{path}/{kind}-images-idx3-ubyte.gz'
    
    with gzip.open(labels_path, 'rb') as lbpath:
        labels = np.frombuffer(lbpath.read(), dtype=np.uint8, offset=8)
    
    with gzip.open(images_path, 'rb') as imgpath:
        images = np.frombuffer(imgpath.read(), dtype=np.uint8, offset=16).reshape(len(labels), 784)
    
    return images, labels

def get_MNIST_data(num_training=50000, num_validation=10000, num_test=10000):
    mnist_dir = r'path/to/MNIST'
    X_train, y_train = load_mnist(mnist_dir, kind='train')
    X_test, y_test = load_mnist(mnist_dir, kind='t10k')
    
    mask = range(num_training, num_training + num_validation)
    X_val = X_train[mask]
    y_val = y_train[mask]
    
    mask = range(num_training)
    X_train = X_train[mask]
    y_train = y_train[mask]
    
    mask = range(num_test)
    X_test = X_test[mask]
    y_test = y_test[mask]
    
    # normalize images
    mean_image = np.mean(X_train, axis=0)
    X_train -= mean_image
    X_val -= mean_image
    X_test -= mean_image
    
    # reshape images to 28x28x1
    X_train = X_train.reshape(-1, 1, 28, 28)
    X_val = X_val.reshape(-1, 1, 28, 28)
    X_test = X_test.reshape(-1, 1, 28, 28)
    
    return {
        'X_train': X_train, 'y_train': y_train,
        'X_val': X_val, 'y_val': y_val,
        'X_test': X_test, 'y_test': y_test
    }

其中 `load_mnist` 函数会从指定路径加载MNIST数据集，返回的 `images` 是一个形状为 `(num_samples, 784)` 的numpy数组，`labels`是一个形状为 `(num_samples,)` 的numpy数组。 `get_MNIST_data` 函数会调用 `load_mnist` 函数来加载数据集，并进行预处理，最后返回一个字典，包含训练集、验证集和测试集的图像和标签。

import os import random import numpy as np import cv2 import keras from create_unet import create_model img_path = 'data_enh/img' mask_path = 'data_enh/mask' # 训练集与测试集的切分 img_files = np.array(os.listdir(img_path)) data_num = len(img_files) train_num = int(data_num * 0.8) train_ind = random.sample(range(data_num), train_num) test_ind = list(set(range(data_num)) - set(train_ind)) train_ind = np.array(train_ind) test_ind = np.array(test_ind) train_img = img_files[train_ind] # 训练的数据 test_img = img_files[test_ind] # 测试的数据 def get_mask_name(img_name): mask = [] for i in img_name: mask_name = i.replace('.jpg', '.png') mask.append(mask_name) return np.array(mask) train_mask = get_mask_name(train_img) test_msak = get_mask_name(test_img) def generator(img, mask, batch_size): num = len(img) while True: IMG = [] MASK = [] for i in range(batch_size): index = np.random.choice(num) img_name = img[index] mask_name = mask[index] img_temp = os.path.join(img_path, img_name) mask_temp = os.path.join(mask_path, mask_name) temp_img = cv2.imread(img_temp) temp_mask = cv2.imread(mask_temp, 0)/255 temp_mask = np.reshape(temp_mask, [256, 256, 1]) IMG.append(temp_img) MASK.append(temp_mask) IMG = np.array(IMG) MASK = np.array(MASK) yield IMG, MASK # train_data = generator(train_img, train_mask, 32) # temp_data = train_data.__next__() # 计算dice系数 def dice_coef(y_true, y_pred): y_true_f = keras.backend.flatten(y_true) y_pred_f = keras.backend.flatten(y_pred) intersection = keras.backend.sum(y_true_f * y_pred_f) area_true = keras.backend.sum(y_true_f * y_true_f) area_pred = keras.backend.sum(y_pred_f * y_pred_f) dice = (2 * intersection + 1)/(area_true + area_pred + 1) return dice # 自定义损失函数，dice_loss def dice_coef_loss(y_true, y_pred): return 1 - dice_coef(y_true, y_pred) # 模型的创建 model = create_model() # 模型的编译 model.compile(optimizer='Adam', loss=dice_coef_loss, metrics=[dice_coef]) # 模型的训练 history = model.fit_generator(generator(train_img, train_mask, 4), steps_per_epoch=100, epochs=10, validation_data=generator(test_img, test_msak, 4), validation_steps=4 ) # 模型的保存 model.save('unet_model.h5') # 模型的读取 model = keras.models.load_model('unet_model.h5', custom_objects={'dice_coef_loss': dice_coef_loss, 'dice_coef': dice_coef}) # 获取测试数据 test_generator = generator(test_img, test_msak, 32) img, mask = test_generator.__next__() # 模型的测试 model.evaluate(img, mask) # [0.11458712816238403, 0.885412871837616] 94%

上面这段代码是在导入一些库。它导入了 OS 库，Random 库，NumPy 库，CV2 库，Keras 库，以及一个叫做 Create_unet 的自定义模块。它还定义了两个字符串变量：img_path 和 mask_path，分别存储了图像数据和掩码数据的路径。