# -*- coding: utf-8 -*- '''VGG16 model for Keras. # Reference: - [Very Deep Convolutional Networks for Large-Scale Image Recognition](https://arxiv.org/abs/1409.1556) ''' from __future__ import print_function import numpy as np import warnings from keras.models import Model from keras.layers import Flatten, Dense, Input from keras.layers import Convolution2D, MaxPooling2D from keras.preprocessing import image from keras.utils.layer_utils import convert_all_kernels_in_model from keras.utils.data_utils import get_file from keras import backend as K # from imagenet_utils import decode_predictions, preprocess_input TH_WEIGHTS_PATH = 'https://github.com/fchollet/deep-learning-models/releases/download/v0.1/vgg16_weights_th_dim_ordering_th_kernels.h5' TF_WEIGHTS_PATH = 'https://github.com/fchollet/deep-learning-models/releases/download/v0.1/vgg16_weights_tf_dim_ordering_tf_kernels.h5' TH_WEIGHTS_PATH_NO_TOP = 'https://github.com/fchollet/deep-learning-models/releases/download/v0.1/vgg16_weights_th_dim_ordering_th_kernels_notop.h5' TF_WEIGHTS_PATH_NO_TOP = 'https://github.com/fchollet/deep-learning-models/releases/download/v0.1/vgg16_weights_tf_dim_ordering_tf_kernels_notop.h5' def VGG16(include_top=True, weights='imagenet', input_tensor=None): '''Instantiate the VGG16 architecture, optionally loading weights pre-trained on ImageNet. Note that when using TensorFlow, for best performance you should set `image_dim_ordering="tf"` in your Keras config at ~/.keras/keras.json. The model and the weights are compatible with both TensorFlow and Theano. The dimension ordering convention used by the model is the one specified in your Keras config file. # Arguments include_top: whether to include the 3 fully-connected layers at the top of the network. weights: one of `None` (random initialization) or "imagenet" (pre-training on ImageNet). input_tensor: optional Keras tensor (i.e. output of `layers.Input()`) to use as image input for the model. # Returns A Keras model instance. ''' if weights not in {'imagenet', None}: raise ValueError('The `weights` argument should be either ' '`None` (random initialization) or `imagenet` ' '(pre-training on ImageNet).') # Determine proper input shape if K.image_dim_ordering() == 'th': if include_top: input_shape = (3, 224, 224) else: input_shape = (3, None, None) else: if include_top: input_shape = (224, 224, 3) else: input_shape = (None, None, 3) if input_tensor is None: img_input = Input(shape=input_shape) else: if not K.is_keras_tensor(input_tensor): img_input = Input(tensor=input_tensor) else: img_input = input_tensor # Block 1 x = Convolution2D(64, 3, 3, activation='relu', border_mode='same', name='block1_conv1')(img_input) x = Convolution2D(64, 3, 3, activation='relu', border_mode='same', name='block1_conv2')(x) x = MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x) # Block 2 x = Convolution2D(128, 3, 3, activation='relu', border_mode='same', name='block2_conv1')(x) x = Convolution2D(128, 3, 3, activation='relu', border_mode='same', name='block2_conv2')(x) x = MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x) # Block 3 x = Convolution2D(256, 3, 3, activation='relu', border_mode='same', name='block3_conv1')(x) x = Convolution2D(256, 3, 3, activation='relu', border_mode='same', name='block3_conv2')(x) x = Convolution2D(256, 3, 3, activation='relu', border_mode='same', name='block3_conv3')(x) x = MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x) # Block 4 x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block4_conv1')(x) x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block4_conv2')(x) x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block4_conv3')(x) x = MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x) # Block 5 x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block5_conv1')(x) x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block5_conv2')(x) x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block5_conv3')(x) x = MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x) if include_top: # Classification block x = Flatten(name='flatten')(x) x = Dense(4096, activation='relu', name='fc1')(x) x = Dense(4096, activation='relu', name='fc2')(x) x = Dense(1000, activation='softmax', name='predictions')(x) # Create model model = Model(img_input, x) # load weights if weights == 'imagenet': print('K.image_dim_ordering:', K.image_dim_ordering()) if K.image_dim_ordering() == 'th': if include_top: weights_path = get_file('vgg16_weights_th_dim_ordering_th_kernels.h5', TH_WEIGHTS_PATH, cache_subdir='models') else: weights_path = get_file('vgg16_weights_th_dim_ordering_th_kernels_notop.h5', TH_WEIGHTS_PATH_NO_TOP, cache_subdir='models') model.load_weights(weights_path) if K.backend() == 'tensorflow': warnings.warn('You are using the TensorFlow backend, yet you ' 'are using the Theano ' 'image dimension ordering convention ' '(`image_dim_ordering="th"`). ' 'For best performance, set ' '`image_dim_ordering="tf"` in ' 'your Keras config ' 'at ~/.keras/keras.json.') convert_all_kernels_in_model(model) else: if include_top: weights_path = get_file('vgg16_weights_tf_dim_ordering_tf_kernels.h5', TF_WEIGHTS_PATH, cache_subdir='models') else: weights_path = get_file('vgg16_weights_tf_dim_ordering_tf_kernels_notop.h5', TF_WEIGHTS_PATH_NO_TOP, cache_subdir='models') model.load_weights(weights_path) if K.backend() == 'theano': convert_all_kernels_in_model(model) return model if __name__ == '__main__': model = VGG16(include_top=True, weights='imagenet') img_path = 'elephant.jpg' img = image.load_img(img_path, target_size=(224, 224)) x = image.img_to_array(img) x = np.expand_dims(x, axis=0) x = preprocess_input(x) print('Input image shape:', x.shape) preds = model.predict(x) print('Predicted:', decode_predictions(preds))