Densenet-Tensorflow
Tensorflow implementation of Densenet using Cifar10, MNIST
- The code that implements this paper is Densenet.py
- There is a slight difference, I used AdamOptimizer
If you want to see the original author's code or other implementations, please refer to this link
Requirements
- Tensorflow 1.x
- Python 3.x
- tflearn (If you are easy to use global average pooling, you should install tflearn
However, I implemented it using tf.layers, so don't worryIssue
- I used tf.contrib.layers.batch_norm
def Batch_Normalization(x, training, scope):
with arg_scope([batch_norm],
scope=scope,
updates_collections=None,
decay=0.9,
center=True,
scale=True,
zero_debias_moving_mean=True) :
return tf.cond(training,
lambda : batch_norm(inputs=x, is_training=training, reuse=None),
lambda : batch_norm(inputs=x, is_training=training, reuse=True))- If not enough GPU memory, Please edit the code
with tf.Session() as sess : NO
with tf.Session(config=tf.ConfigProto(allow_soft_placement=True)) as sess : OKIdea
What is the "Global Average Pooling" ?
def Global_Average_Pooling(x, stride=1) :
width = np.shape(x)[1]
height = np.shape(x)[2]
pool_size = [width, height]
return tf.layers.average_pooling2d(inputs=x, pool_size=pool_size, strides=stride)
# The stride value does not matter- If you use tflearn, please refer to this link
def Global_Average_Pooling(x):
return tflearn.layers.conv.global_avg_pool(x, name='Global_avg_pooling')What is the "Dense Connectivity" ?
What is the "Densenet Architecture" ?
def Dense_net(self, input_x):
x = conv_layer(input_x, filter=2 * self.filters, kernel=[7,7], stride=2, layer_name='conv0')
x = Max_Pooling(x, pool_size=[3,3], stride=2)
x = self.dense_block(input_x=x, nb_layers=6, layer_name='dense_1')
x = self.transition_layer(x, scope='trans_1')
x = self.dense_block(input_x=x, nb_layers=12, layer_name='dense_2')
x = self.transition_layer(x, scope='trans_2')
x = self.dense_block(input_x=x, nb_layers=48, layer_name='dense_3')
x = self.transition_layer(x, scope='trans_3')
x = self.dense_block(input_x=x, nb_layers=32, layer_name='dense_final')
x = Batch_Normalization(x, training=self.training, scope='linear_batch')
x = Relu(x)
x = Global_Average_Pooling(x)
x = Linear(x)
return xWhat is the "Dense Block" ?
def dense_block(self, input_x, nb_layers, layer_name):
with tf.name_scope(layer_name):
layers_concat = list()
layers_concat.append(input_x)
x = self.bottleneck_layer(input_x, scope=layer_name + '_bottleN_' + str(0))
layers_concat.append(x)
for i in range(nb_layers - 1):
x = Concatenation(layers_concat)
x = self.bottleneck_layer(x, scope=layer_name + '_bottleN_' + str(i + 1))
layers_concat.append(x)
x = Concatenation(layers_concat)
return xWhat is the "Bottleneck Layer" ?
def bottleneck_layer(self, x, scope):
with tf.name_scope(scope):
x = Batch_Normalization(x, training=self.training, scope=scope+'_batch1')
x = Relu(x)
x = conv_layer(x, filter=4 * self.filters, kernel=[1,1], layer_name=scope+'_conv1')
x = Drop_out(x, rate=dropout_rate, training=self.training)
x = Batch_Normalization(x, training=self.training, scope=scope+'_batch2')
x = Relu(x)
x = conv_layer(x, filter=self.filters, kernel=[3,3], layer_name=scope+'_conv2')
x = Drop_out(x, rate=dropout_rate, training=self.training)
return xWhat is the "Transition Layer" ?
def transition_layer(self, x, scope):
with tf.name_scope(scope):
x = Batch_Normalization(x, training=self.training, scope=scope+'_batch1')
x = Relu(x)
x = conv_layer(x, filter=self.filters, kernel=[1,1], layer_name=scope+'_conv1')
x = Drop_out(x, rate=dropout_rate, training=self.training)
x = Average_pooling(x, pool_size=[2,2], stride=2)
return xCompare Structure (CNN, ResNet, DenseNet)
Results
- (MNIST) The highest test accuracy is 99.2% (This result does not use dropout)
- The number of dense block layers is fixed to 4
for i in range(self.nb_blocks) :
# original : 6 -> 12 -> 48
x = self.dense_block(input_x=x, nb_layers=4, layer_name='dense_'+str(i))
x = self.transition_layer(x, scope='trans_'+str(i))CIFAR-10
CIFAR-100
Image Net
Related works
References
Author
Junho Kim