Tensorflow 自动分割图像

Question

假设我有这样的目录。

full_dataset
|---horse <= 40 images of horse
|---donkey <= 50 images of donkey
|---cow <= 80 images of cow
|---zebra <= <= 30 images of zebra

那我用tensorflow写这个

image_generator = ImageDataGenerator(rescale=1./255)    
my_dataset = image_generator.flow_from_directory(batch_size=32,
                                                 directory='full_dataset',
                                                 shuffle=True,
                                                 target_size=(280, 280),
                                                 class_mode='categorical')

但我想自动拆分那个文件，而不需要手动将目录更改为训练文件夹和测试文件夹。我不想像 https://www.tensorflow.org/tutorials/images/classification)

那样手动拆分它

我做过和失败的事

(x_train, y_train),(x_test, y_test) = my_dataset.load_data()

Answer 1

您不必使用tensorflow 或keras 来划分您的数据集。如果您安装了 sklearn 包，那么您可以简单地使用它：

from sklearn.model_selection import train_test_split
X = ...
Y = ...
x_train, x_test, y_train, y_test = train_test_split(X, Y, test_size=0.2)

你也可以使用 numpy 来达到同样的目的：

import numpy
X = ...
Y = ...
test_size = 0.2
train_nsamples = (1-test_size) * len(Y)
x_train, x_test, y_train, y_test = X[:train_nsamples,:], X[train_nsamples:, :], Y[:train_nsamples, ], Y[train_nsamples:,]

在 Keras 中：

from keras.datasets import mnist
import numpy as np
from sklearn.model_selection import train_test_split

(x_train, y_train), (x_test, y_test) = mnist.load_data()
x = np.concatenate((x_train, x_test))
y = np.concatenate((y_train, y_test))

train_size = 0.7
x_train, x_test, y_train, y_test = train_test_split(x, y, train_size=train_size)

Answer 2

经过试错和折腾了一天，找到了解决办法

第一种方式

import glob
horse = glob.glob('full_dataset/horse/*.*')
donkey = glob.glob('full_dataset/donkey/*.*')
cow = glob.glob('full_dataset/cow/*.*')
zebra = glob.glob('full_dataset/zebra/*.*')

data = []
labels = []

for i in horse:   
    image=tf.keras.preprocessing.image.load_img(i, color_mode='RGB', 
    target_size= (280,280))
    image=np.array(image)
    data.append(image)
    labels.append(0)
for i in donkey:   
    image=tf.keras.preprocessing.image.load_img(i, color_mode='RGB', 
    target_size= (280,280))
    image=np.array(image)
    data.append(image)
    labels.append(1)
for i in cow:   
    image=tf.keras.preprocessing.image.load_img(i, color_mode='RGB', 
    target_size= (280,280))
    image=np.array(image)
    data.append(image)
    labels.append(2)
for i in zebra:   
    image=tf.keras.preprocessing.image.load_img(i, color_mode='RGB', 
    target_size= (280,280))
    image=np.array(image)
    data.append(image)
    labels.append(3)

data = np.array(data)
labels = np.array(labels)

from sklearn.model_selection import train_test_split
X_train, X_test, ytrain, ytest = train_test_split(data, labels, test_size=0.2,
                                                random_state=42)

第二种方式

image_generator = ImageDataGenerator(rescale=1/255, validation_split=0.2)    

train_dataset = image_generator.flow_from_directory(batch_size=32,
                                                 directory='full_dataset',
                                                 shuffle=True,
                                                 target_size=(280, 280), 
                                                 subset="training",
                                                 class_mode='categorical')

validation_dataset = image_generator.flow_from_directory(batch_size=32,
                                                 directory='full_dataset',
                                                 shuffle=True,
                                                 target_size=(280, 280), 
                                                 subset="validation",
                                                 class_mode='categorical')

第二种方式的主要缺点，不能用于显示图片。写validation_dataset[1]会报错。但如果我使用第一种方式，它会起作用：X_test[1]

Tensorflow 自动分割图像

Tensorflow auto split image

tensorflow

image-processing

train-test-split