Question

我学会了从我从帖子中获得的代码实现图像分类器并且它非常有用，但我不知道如何预测图像。我试过但它给出了一个值错误。我仍然初学者

Keras代码： -

from __future__ import print_function
from keras.datasets import cifar10
from keras.preprocessing.image import ImageDataGenerator
from keras.models import Sequential
from keras.layers import Dense, Dropout, Activation, Flatten
from keras.layers import Convolution2D, MaxPooling2D
from keras.optimizers import SGD, Adam
from keras.utils import np_utils
import numpy as np

#seed = 7
#np.random.seed(seed)

batch_size = 50
nb_classes = 10
nb_epoch = 150
data_augmentation = False

# input image dimensions
img_rows, img_cols = 32, 32
# the CIFAR10 images are RGB
img_channels = 3

# the data, shuffled and split between train and test sets
(X_train, y_train), (X_test, y_test) = cifar10.load_data()
print('X_train shape:', X_train.shape)
print(X_train.shape[0], 'train samples')
print(X_test.shape[0], 'test samples')

# convert class vectors to binary class matrices
Y_train = np_utils.to_categorical(y_train, nb_classes)
Y_test = np_utils.to_categorical(y_test, nb_classes)

model = Sequential()

model.add(Convolution2D(32, 3, 3, border_mode='same',
                        input_shape=X_train.shape[1:]))
model.add(Activation('relu'))
model.add(Convolution2D(32, 3, 3, border_mode='same'))
model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Dropout(0.25))

model.add(Convolution2D(64, 3, 3, border_mode='same'))
model.add(Activation('relu'))
model.add(Convolution2D(64, 3, 3, border_mode='same'))
model.add(Activation('relu'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Dropout(0.25))

model.add(Flatten())
model.add(Dense(512))
model.add(Activation('relu'))
model.add(Dropout(0.5))
model.add(Dense(nb_classes))
model.add(Activation('softmax'))

# let's train the model using SGD + momentum (how original).

#sgd = SGD(lr=0.001, decay=1e-6, momentum=0.9, nesterov=True)
sgd= Adam(lr=0.0001, beta_1=0.9, beta_2=0.999, epsilon=1e-08, decay=0.0)
model.compile(loss='categorical_crossentropy',
              optimizer=sgd,
              metrics=['accuracy'])

X_train = X_train.astype('float32')
X_test = X_test.astype('float32')
X_train /= 255
X_test /= 255

if not data_augmentation:
    print('Not using data augmentation.')
    model.fit(X_train, Y_train,
              batch_size=batch_size,
              nb_epoch=nb_epoch,
              validation_data=(X_test, Y_test),
              shuffle=True)

else:
    print('Using real-time data augmentation.')

    # this will do preprocessing and realtime data augmentation
    datagen = ImageDataGenerator(
        featurewise_center=False,  # set input mean to 0 over the dataset
        samplewise_center=False,  # set each sample mean to 0
        featurewise_std_normalization=False,  # divide inputs by std of the dataset
        samplewise_std_normalization=False,  # divide each input by its std
        zca_whitening=False,  # apply ZCA whitening
        rotation_range=0,  # randomly rotate images in the range (degrees, 0 to 180)
        width_shift_range=0.1,  # randomly shift images horizontally (fraction of total width)
        height_shift_range=0.1,  # randomly shift images vertically (fraction of total height)
        horizontal_flip=True,  # randomly flip images
        vertical_flip=False)  # randomly flip images

    # compute quantities required for featurewise normalization
    # (std, mean, and principal components if ZCA whitening is applied)
    datagen.fit(X_train)

    # fit the model on the batches generated by datagen.flow()
    model.fit_generator(datagen.flow(X_train, Y_train,
                        batch_size=batch_size),
                        samples_per_epoch=X_train.shape[0],
                        nb_epoch=nb_epoch,
validation_data=(X_test, Y_test))

model.save('CIFAR10.h5')

我的预测代码： -

from __future__ import print_function
from keras.models import load_model
from keras.utils import np_utils
import numpy as np
import cv2

img_rows, img_cols = 32, 32
model = load_model('CIFAR10.h5')
img = cv2.imread('D:/Study_Material/Python_3_Tutorial/PythonScripts/Machine_Learning/Project/Images/Deer.jpg')
img = cv2.resize(img,(img_rows,img_cols))
Image = np.array(img)
print(model.predict(Image))

错误： -

 Warning (from warnings module):
  File "C:\Users\Na462\AppData\Local\Programs\Python\Python35\lib\site-packages\h5py\__init__.py", line 36
    from ._conv import register_converters as _register_converters
FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`.
Using TensorFlow backend.
Traceback (most recent call last):
  File "D:\Study_Material\Python_3_Tutorial\PythonScripts\Machine_Learning\Project\Keras(Prediction).py", line 12, in <module>
    print(model.predict(Image))
  File "C:\Users\Na462\AppData\Local\Programs\Python\Python35\lib\site-packages\keras\models.py", line 1025, in predict
    steps=steps)
  File "C:\Users\Na462\AppData\Local\Programs\Python\Python35\lib\site-packages\keras\engine\training.py", line 1817, in predict
    check_batch_axis=False)
  File "C:\Users\Na462\AppData\Local\Programs\Python\Python35\lib\site-packages\keras\engine\training.py", line 113, in _standardize_input_data
    'with shape ' + str(data_shape))
ValueError: Error when checking : expected conv2d_1_input to have 4 dimensions, but got array with shape (32, 32, 3)

请告诉我在Keras预测的正确方法，以便我可以在不同的测试用例中实现它。

Answer 1

您得到的错误是因为所有框架都假设图像输入是一批图像，使其成为4d张量，而不是一个图像（3d张量）。要只进行单个图像批次，请将输入扩展为大小（1,32,32,3），开头的1为批量大小为1.

我不太了解keras，但是因为你传递了一个numpy数组，你可以修改你的＆＃39; Image＆＃39;像这样的对象（见倒数第二行）：

img_rows, img_cols = 32, 32
model = load_model('CIFAR10.h5')
img = cv2.imread('D:/Study_Material/Python_3_Tutorial/PythonScripts/Machine_Learning/Project/Images/Deer.jpg')
img = cv2.resize(img,(img_rows,img_cols))
Image = np.expand_dims(np.array(img), axis=0)
print(model.predict(Image))

使用Keras进行预测

1 个答案: