python 为什么我的Ml CNN卡格尔猫/狗节目只吐出一个错误?

ohtdti5x  于 2023-01-12  发布在  Python
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我对机器学习和计算机视觉还很陌生。我正尝试对猫/狗做一个categotrial预测,0代表猫,1代表狗。但是我的model.fit()函数却显示了这个错误。

ValueError: Input 0 of layer sequential_5 is incompatible with the layer: : expected min_ndim=4, found ndim=2. Full shape received: [None, 10000]

这是我的ML模型:

import matplotlib.pyplot as plt
import numpy as np
from PIL import Image
import cv2

#the images are stored in the Folders 'Cat/' and 'Dog/'
animal = ['Cat/','Dog/']
images_cat= []
images_dog=[]

# reads in the images 
for x in animal:
    for i in range(1,12500): # the are images from '1.jpg' till '12499.jpg' for each Cats and Dogs
        try:
            image_path = x+ str(i) +'.jpg'# this gets the path of the images for example 'Cat/1.jpg'
            #print(image_path)
            img = cv2.cvtColor(cv2.imread(image_path), cv2.COLOR_BGR2GRAY)
            img_resized = cv2.resize(img,dsize=(100,100))
            if x == 'Cat/':
                images_cat.append(img_resized)
            elif x == 'Dog/':
                images_dog.append(img_resized)
                
        except cv2.error as e:
            #some images spit out an errer and the apprently can't be read so therefore I just give them the first image to add to the list
            if x == 'Cat/':
                images_cat.append(images_cat[1])
            elif x == 'Dog/':
                images_dog.append(images_dog[1])

# assign targets to values

y_cat = np.zeros(len(images_cat)) # Cat == 0
y_dog = np.ones(len(images_dog)) # Dog == 1

# trainig_images = 80%   test_images= 20%
training_sample_count = round(0.8* len(y_cat))

#list slicing the images to get 80% of the images as calculated above
X_cat_train = images_cat [:training_sample_count]
y_cat_train_fin = y_cat[:training_sample_count]

X_dog_train = images_dog [:training_sample_count]
y_dog_train_fin = y_dog[:training_sample_count]

# create the final training list
X_train = X_cat_train + X_dog_train
y_train=[]

y_train.append(y_cat_train_fin.data)
y_train.append(y_dog_train_fin.data)

y_train = np.reshape(y_train,(19998,))
np.shape(y_train)# output: (19998,)

#normalizing the data
X_train = [x / 255.0 for x in X_train]
X_train = np.reshape(X_train,(19998,10000))
np.shape(X_train) #output: (19998, 10000)

from tensorflow.keras import Sequential
from tensorflow.keras.layers import Dense, Dropout, MaxPooling2D, Conv2D, Flatten 

model = Sequential()
model.add(Conv2D(32,kernel_size=(5,5),padding='same', activation ='relu'))
model.add(MaxPooling2D((3,3)))

model.add(Conv2D(32,kernel_size=(5,5),padding='same', activation ='relu'))
model.add(MaxPooling2D((3,3)))

model.add(Dropout(0.25))
model.add(Flatten())

model.add(Dense(1, activation='softmax'))
model.compile(optimizer='adam', loss="sparse_categorical_crossentropy", metrics=["accuracy"])

model.fit(
    X_train,
    y_train,
    epochs=10,
    batch_size=10000)

我还没有得到测试图像,但我basicly试图训练这个模型的未来数据(像自己的猫或狗的图像,然后预测).我会很高兴,如果有人能帮助我与我的问题,因为我卡住了atm.干杯:)

q7solyqu

q7solyqu1#

你的模型有些问题-
1.您正在执行二元分类,但使用的是多类单标签分类的配置。更改损失和最后一层激活以获得正确的结果。请检查下表以供参考。

1.当Conv2D层需要一个3DTensor时,您将每个样本的一个1D数组传递到Conv2D层。这就是错误expected min_ndim=4, found ndim=2.的原因。预期的维度是(batch, height, width, channels),而得到的是(batch, pixels)。我添加了一个model.add(Reshape((100,100,1), input_shape=(10000,))),它将10000个像素重新整形为(100,100,1),以便能够正确传递到Conv2D层。
1.最后,你有19998个样本图像。虽然可能,但批量大小为10000是没有意义的。批量大小是将导致梯度更新的样本数。在你的情况下,由于19998/10000~2,每个时期只有2次梯度更新。我建议批量大小为128或64或32。我在model.fit中将其设置为128
在下面查找更新的代码。

from tensorflow.keras import Sequential
from tensorflow.keras.layers import Dense, Dropout, MaxPooling2D, Conv2D, Flatten 

X_train = np.random.random((500, 10000))
Y_train = np.random.randint(0,2,(500,)) #0, 0, 1, 0, 1...

model = Sequential()
model.add(Reshape((100,100,1), input_shape=(10000,)))
model.add(Conv2D(32,kernel_size=(5,5), padding='same', activation ='relu'))
model.add(MaxPooling2D((3,3)))

model.add(Conv2D(32,kernel_size=(5,5),padding='same', activation ='relu'))
model.add(MaxPooling2D((3,3)))

model.add(Dropout(0.25))
model.add(Flatten())

model.add(Dense(1, activation='sigmoid'))
model.compile(optimizer='adam', loss="binary_crossentropy", metrics=["accuracy"])

model.fit(
    X_train,
    Y_train,
    epochs=3,
    batch_size=128)
Epoch 1/3
4/4 [==============================] - 2s 498ms/step - loss: 0.7019 - accuracy: 0.4680
Epoch 2/3
4/4 [==============================] - 2s 534ms/step - loss: 0.6939 - accuracy: 0.5260
Epoch 3/3
4/4 [==============================] - 2s 524ms/step - loss: 0.6922 - accuracy: 0.5240
wsewodh2

wsewodh22#

Conv2D层需要形状为(batch_size, x, y, depth)的输入。您的X_train正在被整形为只有大小(batch_size, x*y),这不是Conv2D所需要的。
去掉这个整形可能会有用:X_train = np.reshape(X_train,(19998,10000))。如果不是,则可以将其整形为(19998, 100, 100, 1)

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