Add inception v3 example

Author: fchollet

examples/inception_v3.py

@@ -0,0 +1,290 @@
+'''This script demonstrates how to build the Inception v3 architecture
+using the Keras functional API.
+We are not actually training it here, for lack of appropriate data.
+
+For more information about this architecture, see:
+
+"Rethinking the Inception Architecture for Computer Vision"
+Christian Szegedy, Vincent Vanhoucke, Sergey Ioffe, Jonathon Shlens, Zbigniew Wojna
+http://arxiv.org/abs/1512.00567
+'''
+from keras.layers import Convolution2D, MaxPooling2D, AveragePooling2D
+from keras.layers import BatchNormalization, Flatten, Dense, Dropout
+from keras.layers import Input, merge
+from keras.models import Model
+from keras import regularizers
+
+
+# global constants
+NB_CLASS = 1000  # number of classes
+DIM_ORDERING = 'th'  # 'th' (channels, width, height) or 'tf' (width, height, channels)
+WEIGHT_DECAY = 0.  # L2 regularization factor
+USE_BN = False  # whether to use batch normalization
+
+
+def conv2D_bn(x, nb_filter, nb_row, nb_col,
+              border_mode='same', subsample=(1, 1),
+              activation='relu', batch_norm=USE_BN,
+              weight_decay=WEIGHT_DECAY, dim_ordering=DIM_ORDERING):
+    '''Utility function to apply to a tensor a module conv + BN
+    with optional weight decay (L2 weight regularization).
+    '''
+    if weight_decay:
+        W_regularizer = regularizers.l2(weight_decay)
+        b_regularizer = regularizers.l2(weight_decay)
+    else:
+        W_regularizer = None
+        b_regularizer = None
+    x = Convolution2D(nb_filter, nb_row, nb_col,
+                      subsample=subsample,
+                      activation=activation,
+                      border_mode=border_mode,
+                      W_regularizer=W_regularizer,
+                      b_regularizer=b_regularizer,
+                      dim_ordering=dim_ordering)(x)
+    if batch_norm:
+        x = BatchNormalization()(x)
+    return x
+
+# Define image input layer
+
+if DIM_ORDERING == 'th':
+    img_input = Input(shape=(3, 299, 299))
+    CONCAT_AXIS = 1
+elif DIM_ORDERING == 'tf':
+    img_input = Input(shape=(299, 299, 3))
+    CONCAT_AXIS = 3
+else:
+    raise Exception('Invalid dim ordering: ' + str(DIM_ORDERING))
+
+# Entry module
+
+x = conv2D_bn(img_input, 32, 3, 3, subsample=(2, 2), border_mode='valid')
+x = conv2D_bn(x, 32, 3, 3, border_mode='valid')
+x = conv2D_bn(x, 64, 3, 3)
+x = MaxPooling2D((3, 3), strides=(2, 2), dim_ordering=DIM_ORDERING)(x)
+
+x = conv2D_bn(x, 80, 1, 1, border_mode='valid')
+x = conv2D_bn(x, 192, 3, 3, border_mode='valid')
+x = MaxPooling2D((3, 3), strides=(2, 2), dim_ordering=DIM_ORDERING)(x)
+
+# mixed: 35 x 35 x 256
+
+branch1x1 = conv2D_bn(x, 64, 1, 1)
+
+branch5x5 = conv2D_bn(x, 48, 1, 1)
+branch5x5 = conv2D_bn(branch5x5, 64, 5, 5)
+
+branch3x3dbl = conv2D_bn(x, 64, 1, 1)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 96, 3, 3)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 96, 3, 3)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 32, 1, 1)
+x = merge([branch1x1, branch5x5, branch3x3dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed_1: 35 x 35 x 288
+
+branch1x1 = conv2D_bn(x, 64, 1, 1)
+
+branch5x5 = conv2D_bn(x, 48, 1, 1)
+branch5x5 = conv2D_bn(branch5x5, 64, 5, 5)
+
+branch3x3dbl = conv2D_bn(x, 64, 1, 1)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 96, 3, 3)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 96, 3, 3)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 32, 1, 1)
+x = merge([branch1x1, branch5x5, branch3x3dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed2: 35 x 35 x 288
+
+branch1x1 = conv2D_bn(x, 64, 1, 1)
+
+branch5x5 = conv2D_bn(x, 48, 1, 1)
+branch5x5 = conv2D_bn(branch5x5, 64, 5, 5)
+
+branch3x3dbl = conv2D_bn(x, 64, 1, 1)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 96, 3, 3)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 96, 3, 3)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 64, 1, 1)
+x = merge([branch1x1, branch5x5, branch3x3dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed3: 17 x 17 x 768
+
+branch3x3 = conv2D_bn(x, 384, 3, 3, subsample=(2, 2), border_mode='valid')
+
+branch3x3dbl = conv2D_bn(x, 64, 1, 1)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 96, 3, 3)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 96, 3, 3, subsample=(2, 2), border_mode='valid')
+
+branch_pool = MaxPooling2D((3, 3), strides=(2, 2), dim_ordering=DIM_ORDERING)(x)
+x = merge([branch3x3, branch3x3dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed4: 17 x 17 x 768
+
+branch1x1 = conv2D_bn(x, 192, 1, 1)
+
+branch7x7 = conv2D_bn(x, 128, 1, 1)
+branch7x7 = conv2D_bn(branch7x7, 128, 1, 7)
+branch7x7 = conv2D_bn(branch7x7, 192, 7, 1)
+
+branch7x7dbl = conv2D_bn(x, 128, 1, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 128, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 128, 1, 7)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 128, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 128, 1, 7)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 192, 1, 1)
+x = merge([branch1x1, branch7x7, branch7x7dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed5: 17 x 17 x 768
+
+branch1x1 = conv2D_bn(x, 192, 1, 1)
+
+branch7x7 = conv2D_bn(x, 160, 1, 1)
+branch7x7 = conv2D_bn(branch7x7, 160, 1, 7)
+branch7x7 = conv2D_bn(branch7x7, 192, 7, 1)
+
+branch7x7dbl = conv2D_bn(x, 160, 1, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 160, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 1, 7)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 160, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 1, 7)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 192, 1, 1)
+x = merge([branch1x1, branch7x7, branch7x7dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed5: 17 x 17 x 768
+
+branch1x1 = conv2D_bn(x, 192, 1, 1)
+
+branch7x7 = conv2D_bn(x, 160, 1, 1)
+branch7x7 = conv2D_bn(branch7x7, 160, 1, 7)
+branch7x7 = conv2D_bn(branch7x7, 192, 7, 1)
+
+branch7x7dbl = conv2D_bn(x, 160, 1, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 160, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 1, 7)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 160, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 1, 7)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 192, 1, 1)
+x = merge([branch1x1, branch7x7, branch7x7dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed6: 17 x 17 x 768
+
+branch1x1 = conv2D_bn(x, 192, 1, 1)
+
+branch7x7 = conv2D_bn(x, 160, 1, 1)
+branch7x7 = conv2D_bn(branch7x7, 160, 1, 7)
+branch7x7 = conv2D_bn(branch7x7, 192, 7, 1)
+
+branch7x7dbl = conv2D_bn(x, 160, 1, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 160, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 1, 7)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 160, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 1, 7)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 192, 1, 1)
+x = merge([branch1x1, branch7x7, branch7x7dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed7: 17 x 17 x 768
+
+branch1x1 = conv2D_bn(x, 192, 1, 1)
+
+branch7x7 = conv2D_bn(x, 192, 1, 1)
+branch7x7 = conv2D_bn(branch7x7, 192, 1, 7)
+branch7x7 = conv2D_bn(branch7x7, 192, 7, 1)
+
+branch7x7dbl = conv2D_bn(x, 160, 1, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 1, 7)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 7, 1)
+branch7x7dbl = conv2D_bn(branch7x7dbl, 192, 1, 7)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 192, 1, 1)
+x = merge([branch1x1, branch7x7, branch7x7dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# Auxiliary head
+
+aux_logits = AveragePooling2D((5, 5), strides=(3, 3), dim_ordering=DIM_ORDERING)(x)
+aux_logits = conv2D_bn(aux_logits, 128, 1, 1)
+aux_logits = conv2D_bn(aux_logits, 728, 5, 5, border_mode='valid')
+aux_logits = Flatten()(aux_logits)
+aux_preds = Dense(NB_CLASS, activation='softmax')(aux_logits)
+
+# mixed8: 8 x 8 x 1280
+
+branch3x3 = conv2D_bn(x, 192, 1, 1)
+branch3x3 = conv2D_bn(branch3x3, 192, 3, 3, subsample=(2, 2), border_mode='valid')
+
+branch7x7x3 = conv2D_bn(x, 192, 1, 1)
+branch7x7x3 = conv2D_bn(branch7x7x3, 192, 1, 7)
+branch7x7x3 = conv2D_bn(branch7x7x3, 192, 7, 1)
+branch7x7x3 = conv2D_bn(branch7x7x3, 192, 3, 3, subsample=(2, 2), border_mode='valid')
+
+branch_pool = AveragePooling2D((3, 3), strides=(2, 2), dim_ordering=DIM_ORDERING)(x)
+x = merge([branch3x3, branch7x7x3, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed9: 8 x 8 x 2048
+
+branch1x1 = conv2D_bn(x, 320, 1, 1)
+
+branch3x3 = conv2D_bn(x, 384, 1, 1)
+branch3x3_1 = conv2D_bn(branch3x3, 384, 1, 3)
+branch3x3_2 = conv2D_bn(branch3x3, 384, 3, 1)
+branch3x3 = merge([branch3x3_1, branch3x3_2], mode='concat', concat_axis=CONCAT_AXIS)
+
+branch3x3dbl = conv2D_bn(x, 448, 1, 1)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 384, 3, 3)
+branch3x3dbl_1 = conv2D_bn(branch3x3dbl, 384, 1, 3)
+branch3x3dbl_2 = conv2D_bn(branch3x3dbl, 384, 3, 1)
+branch3x3dbl = merge([branch3x3dbl_1, branch3x3dbl_2], mode='concat', concat_axis=CONCAT_AXIS)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 192, 1, 1)
+x = merge([branch1x1, branch3x3, branch3x3dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# mixed10: 8 x 8 x 2048
+
+branch1x1 = conv2D_bn(x, 320, 1, 1)
+
+branch3x3 = conv2D_bn(x, 384, 1, 1)
+branch3x3_1 = conv2D_bn(branch3x3, 384, 1, 3)
+branch3x3_2 = conv2D_bn(branch3x3, 384, 3, 1)
+branch3x3 = merge([branch3x3_1, branch3x3_2], mode='concat', concat_axis=CONCAT_AXIS)
+
+branch3x3dbl = conv2D_bn(x, 448, 1, 1)
+branch3x3dbl = conv2D_bn(branch3x3dbl, 384, 3, 3)
+branch3x3dbl_1 = conv2D_bn(branch3x3dbl, 384, 1, 3)
+branch3x3dbl_2 = conv2D_bn(branch3x3dbl, 384, 3, 1)
+branch3x3dbl = merge([branch3x3dbl_1, branch3x3dbl_2], mode='concat', concat_axis=CONCAT_AXIS)
+
+branch_pool = AveragePooling2D((3, 3), strides=(1, 1), border_mode='same', dim_ordering=DIM_ORDERING)(x)
+branch_pool = conv2D_bn(branch_pool, 192, 1, 1)
+x = merge([branch1x1, branch3x3, branch3x3dbl, branch_pool], mode='concat', concat_axis=CONCAT_AXIS)
+
+# Final pooling and prediction
+
+x = AveragePooling2D((8, 8), strides=(1, 1), dim_ordering=DIM_ORDERING)(x)
+x = Dropout(0.5)(x)
+x = Flatten()(x)
+preds = Dense(NB_CLASS, activation='softmax')(x)
+
+# Define model
+
+model = Model(input=img_input, output=[preds, aux_preds])
+model.compile('rmsprop', 'categorical_crossentropy')
+
+# train via e.g. `model.fit(x_train, [y_train] * 2, batch_size=32, nb_epoch=100)`
+# Note that for a large dataset it would be preferable
+# to train using `fit_generator` (see Keras docs).