def dropout(inputs, keep_prob=0.5, is_training=True, scope=None):
"""Returns a dropout layer applied to the input.
Args:
inputs: the tensor to pass to the Dropout layer.
keep_prob: the probability of keeping each input unit.
is_training: whether or not the model is in training mode. If so, dropout is
applied and values scaled. Otherwise, inputs is returned.
scope: Optional scope for op_scope.
Returns:
a tensor representing the output of the operation.
"""
if is_training and keep_prob > 0:
with tf.op_scope([inputs], scope, 'Dropout'):
return tf.nn.dropout(inputs, keep_prob)
else:
return inputs
python类op_scope()的实例源码
def flatten(inputs, scope=None):
"""Flattens the input while maintaining the batch_size.
Assumes that the first dimension represents the batch.
Args:
inputs: a tensor of size [batch_size, ...].
scope: Optional scope for op_scope.
Returns:
a flattened tensor with shape [batch_size, k].
Raises:
ValueError: if inputs.shape is wrong.
"""
if len(inputs.get_shape()) < 2:
raise ValueError('Inputs must be have a least 2 dimensions')
dims = inputs.get_shape()[1:]
k = dims.num_elements()
with tf.op_scope([inputs], scope, 'Flatten'):
return tf.reshape(inputs, [-1, k])
def l2_regularizer(weight=1.0, scope=None):
"""Define a L2 regularizer.
Args:
weight: scale the loss by this factor.
scope: Optional scope for op_scope.
Returns:
a regularizer function.
"""
def regularizer(tensor):
with tf.op_scope([tensor], scope, 'L2Regularizer'):
l2_weight = tf.convert_to_tensor(weight,
dtype=tensor.dtype.base_dtype,
name='weight')
return tf.mul(l2_weight, tf.nn.l2_loss(tensor), name='value')
return regularizer
def l1_l2_regularizer(weight_l1=1.0, weight_l2=1.0, scope=None):
"""Define a L1L2 regularizer.
Args:
weight_l1: scale the L1 loss by this factor.
weight_l2: scale the L2 loss by this factor.
scope: Optional scope for op_scope.
Returns:
a regularizer function.
"""
def regularizer(tensor):
with tf.op_scope([tensor], scope, 'L1L2Regularizer'):
weight_l1_t = tf.convert_to_tensor(weight_l1,
dtype=tensor.dtype.base_dtype,
name='weight_l1')
weight_l2_t = tf.convert_to_tensor(weight_l2,
dtype=tensor.dtype.base_dtype,
name='weight_l2')
reg_l1 = tf.mul(weight_l1_t, tf.reduce_sum(tf.abs(tensor)),
name='value_l1')
reg_l2 = tf.mul(weight_l2_t, tf.nn.l2_loss(tensor),
name='value_l2')
return tf.add(reg_l1, reg_l2, name='value')
return regularizer
def l1_loss(tensor, weight=1.0, scope=None):
"""Define a L1Loss, useful for regularize, i.e. lasso.
Args:
tensor: tensor to regularize.
weight: scale the loss by this factor.
scope: Optional scope for op_scope.
Returns:
the L1 loss op.
"""
with tf.op_scope([tensor], scope, 'L1Loss'):
weight = tf.convert_to_tensor(weight,
dtype=tensor.dtype.base_dtype,
name='loss_weight')
loss = tf.mul(weight, tf.reduce_sum(tf.abs(tensor)), name='value')
tf.add_to_collection(LOSSES_COLLECTION, loss)
return loss
def l2_loss(tensor, weight=1.0, scope=None):
"""Define a L2Loss, useful for regularize, i.e. weight decay.
Args:
tensor: tensor to regularize.
weight: an optional weight to modulate the loss.
scope: Optional scope for op_scope.
Returns:
the L2 loss op.
"""
with tf.op_scope([tensor], scope, 'L2Loss'):
weight = tf.convert_to_tensor(weight,
dtype=tensor.dtype.base_dtype,
name='loss_weight')
loss = tf.mul(weight, tf.nn.l2_loss(tensor), name='value')
tf.add_to_collection(LOSSES_COLLECTION, loss)
return loss
def eval_image(image, height, width, scope=None):
"""Prepare one image for evaluation.
Args:
image: 3-D float Tensor
height: integer
width: integer
scope: Optional scope for op_scope.
Returns:
3-D float Tensor of prepared image.
"""
with tf.op_scope([image, height, width], scope, 'eval_image'):
# Crop the central region of the image with an area containing 87.5% of
# the original image.
image = tf.image.central_crop(image, central_fraction=0.875)
# Resize the image to the original height and width.
image = tf.expand_dims(image, 0)
image = tf.image.resize_bilinear(image, [height, width],
align_corners=False)
image = tf.squeeze(image, [0])
return image
def decode_jpeg(image_buffer, scope=None): # , dtype=tf.float32):
"""Decode a JPEG string into one 3-D float image Tensor.
Args:
image_buffer: scalar string Tensor.
scope: Optional scope for op_scope.
Returns:
3-D float Tensor with values ranging from [0, 1).
"""
# with tf.op_scope([image_buffer], scope, 'decode_jpeg'):
# with tf.name_scope(scope, 'decode_jpeg', [image_buffer]):
with tf.name_scope(scope or 'decode_jpeg'):
# Decode the string as an RGB JPEG.
# Note that the resulting image contains an unknown height and width
# that is set dynamically by decode_jpeg. In other words, the height
# and width of image is unknown at compile-time.
image = tf.image.decode_jpeg(image_buffer, channels=3,
fancy_upscaling=False,
dct_method='INTEGER_FAST')
# image = tf.Print(image, [tf.shape(image)], 'Image shape: ')
return image
def one_hot_encoding(labels, num_classes, scope=None):
"""Transform numeric labels into onehot_labels.
Args:
labels: [batch_size] target labels.
num_classes: total number of classes.
scope: Optional scope for op_scope.
Returns:
one hot encoding of the labels.
"""
with tf.op_scope([labels], scope, 'OneHotEncoding'):
batch_size = labels.get_shape()[0]
indices = tf.expand_dims(tf.range(0, batch_size), 1)
labels = tf.cast(tf.expand_dims(labels, 1), indices.dtype)
concated = tf.concat(1, [indices, labels])
onehot_labels = tf.sparse_to_dense(
concated, tf.pack([batch_size, num_classes]), 1.0, 0.0)
onehot_labels.set_shape([batch_size, num_classes])
return onehot_labels
def dropout(inputs, keep_prob=0.5, is_training=True, scope=None):
"""Returns a dropout layer applied to the input.
Args:
inputs: the tensor to pass to the Dropout layer.
keep_prob: the probability of keeping each input unit.
is_training: whether or not the model is in training mode. If so, dropout is
applied and values scaled. Otherwise, inputs is returned.
scope: Optional scope for op_scope.
Returns:
a tensor representing the output of the operation.
"""
if is_training and keep_prob > 0:
with tf.op_scope([inputs], scope, 'Dropout'):
return tf.nn.dropout(inputs, keep_prob)
else:
return inputs
def flatten(inputs, scope=None):
"""Flattens the input while maintaining the batch_size.
Assumes that the first dimension represents the batch.
Args:
inputs: a tensor of size [batch_size, ...].
scope: Optional scope for op_scope.
Returns:
a flattened tensor with shape [batch_size, k].
Raises:
ValueError: if inputs.shape is wrong.
"""
if len(inputs.get_shape()) < 2:
raise ValueError('Inputs must be have a least 2 dimensions')
dims = inputs.get_shape()[1:]
k = dims.num_elements()
with tf.op_scope([inputs], scope, 'Flatten'):
return tf.reshape(inputs, [-1, k])
def l2_regularizer(weight=1.0, scope=None):
"""Define a L2 regularizer.
Args:
weight: scale the loss by this factor.
scope: Optional scope for op_scope.
Returns:
a regularizer function.
"""
def regularizer(tensor):
with tf.op_scope([tensor], scope, 'L2Regularizer'):
l2_weight = tf.convert_to_tensor(weight,
dtype=tensor.dtype.base_dtype,
name='weight')
return tf.mul(l2_weight, tf.nn.l2_loss(tensor), name='value')
return regularizer
def l1_l2_regularizer(weight_l1=1.0, weight_l2=1.0, scope=None):
"""Define a L1L2 regularizer.
Args:
weight_l1: scale the L1 loss by this factor.
weight_l2: scale the L2 loss by this factor.
scope: Optional scope for op_scope.
Returns:
a regularizer function.
"""
def regularizer(tensor):
with tf.op_scope([tensor], scope, 'L1L2Regularizer'):
weight_l1_t = tf.convert_to_tensor(weight_l1,
dtype=tensor.dtype.base_dtype,
name='weight_l1')
weight_l2_t = tf.convert_to_tensor(weight_l2,
dtype=tensor.dtype.base_dtype,
name='weight_l2')
reg_l1 = tf.mul(weight_l1_t, tf.reduce_sum(tf.abs(tensor)),
name='value_l1')
reg_l2 = tf.mul(weight_l2_t, tf.nn.l2_loss(tensor),
name='value_l2')
return tf.add(reg_l1, reg_l2, name='value')
return regularizer
def l1_loss(tensor, weight=1.0, scope=None):
"""Define a L1Loss, useful for regularize, i.e. lasso.
Args:
tensor: tensor to regularize.
weight: scale the loss by this factor.
scope: Optional scope for op_scope.
Returns:
the L1 loss op.
"""
with tf.op_scope([tensor], scope, 'L1Loss'):
weight = tf.convert_to_tensor(weight,
dtype=tensor.dtype.base_dtype,
name='loss_weight')
loss = tf.mul(weight, tf.reduce_sum(tf.abs(tensor)), name='value')
tf.add_to_collection(LOSSES_COLLECTION, loss)
return loss
def l2_loss(tensor, weight=1.0, scope=None):
"""Define a L2Loss, useful for regularize, i.e. weight decay.
Args:
tensor: tensor to regularize.
weight: an optional weight to modulate the loss.
scope: Optional scope for op_scope.
Returns:
the L2 loss op.
"""
with tf.op_scope([tensor], scope, 'L2Loss'):
weight = tf.convert_to_tensor(weight,
dtype=tensor.dtype.base_dtype,
name='loss_weight')
loss = tf.mul(weight, tf.nn.l2_loss(tensor), name='value')
tf.add_to_collection(LOSSES_COLLECTION, loss)
return loss
def eval_image(image, height, width, scope=None):
"""Prepare one image for evaluation.
Args:
image: 3-D float Tensor
height: integer
width: integer
scope: Optional scope for op_scope.
Returns:
3-D float Tensor of prepared image.
"""
with tf.op_scope([image, height, width], scope, 'eval_image'):
# Crop the central region of the image with an area containing 87.5% of
# the original image.
image = tf.image.central_crop(image, central_fraction=0.875)
# Resize the image to the original height and width.
image = tf.expand_dims(image, 0)
image = tf.image.resize_bilinear(image, [height, width],
align_corners=False)
image = tf.squeeze(image, [0])
return image
def one_hot_encoding(labels, num_classes, scope=None):
"""Transform numeric labels into onehot_labels.
Args:
labels: [batch_size] target labels.
num_classes: total number of classes.
scope: Optional scope for op_scope.
Returns:
one hot encoding of the labels.
"""
with tf.op_scope([labels], scope, 'OneHotEncoding'):
batch_size = labels.get_shape()[0]
indices = tf.expand_dims(tf.range(0, batch_size), 1)
labels = tf.cast(tf.expand_dims(labels, 1), indices.dtype)
concated = tf.concat(1, [indices, labels])
onehot_labels = tf.sparse_to_dense(
concated, tf.pack([batch_size, num_classes]), 1.0, 0.0)
onehot_labels.set_shape([batch_size, num_classes])
return onehot_labels
def dropout(inputs, keep_prob=0.5, is_training=True, scope=None):
"""Returns a dropout layer applied to the input.
Args:
inputs: the tensor to pass to the Dropout layer.
keep_prob: the probability of dropping each input unit.
is_training: whether or not the model is in training mode. If so, dropout is
applied and values scaled. Otherwise, inputs is returned.
scope: Optional scope for op_scope.
Returns:
a tensor representing the output of the operation.
"""
if is_training and keep_prob > 0:
with tf.op_scope([inputs], scope, 'Dropout'):
return tf.nn.dropout(inputs, keep_prob)
else:
return inputs
def flatten(inputs, scope=None):
"""Flattens the input while maintaining the batch_size.
Assumes that the first dimension represents the batch.
Args:
inputs: a tensor of size [batch_size, ...].
scope: Optional scope for op_scope.
Returns:
a flattened tensor with shape [batch_size, k].
Raises:
ValueError: if inputs.shape is wrong.
"""
if len(inputs.get_shape()) < 2:
raise ValueError('Inputs must be have a least 2 dimensions')
dims = inputs.get_shape()[1:]
k = dims.num_elements()
with tf.op_scope([inputs], scope, 'Flatten'):
return tf.reshape(inputs, [-1, k])
def l2_loss(tensor, weight=1.0, scope=None):
"""Define a L2Loss, useful for regularize, i.e. weight decay.
Args:
tensor: tensor to regularize.
weight: an optional weight to modulate the loss.
scope: Optional scope for op_scope.
Returns:
the L2 loss op.
"""
with tf.op_scope([tensor], scope, 'L2Loss'):
weight = tf.convert_to_tensor(weight,
dtype=tensor.dtype.base_dtype,
name='loss_weight')
loss = tf.mul(weight, tf.nn.l2_loss(tensor), name='value')
tf.add_to_collection(LOSSES_COLLECTION, loss)
return loss
