def __init__(self, hidden_dim, cropper,
attention_state_name, hyperparameters, **kwargs):
super(RecurrentAttentionModel, self).__init__(**kwargs)
self.rnn = bricks.RecurrentStack(
[bricks.LSTM(activation=bricks.Tanh(), dim=hidden_dim),
bricks.LSTM(activation=bricks.Tanh(), dim=hidden_dim)],
weights_init=initialization.NormalizedInitialization(
initialization.IsotropicGaussian()),
biases_init=initialization.Constant(0))
# name of the RNN state that determines the parameters of the next glimpse
self.attention_state_name = attention_state_name
self.cropper = cropper
self.construct_locator(**hyperparameters)
self.construct_merger(**hyperparameters)
self.embedder = bricks.Linear(
name="embedder",
input_dim=self.response_mlp.output_dim,
output_dim=4*self.rnn.get_dim("states"),
use_bias=True,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(1))
# don't let blocks touch my children
self.initialization_config_pushed = True
self.children.extend([self.rnn, self.cropper, self.embedder])
# states aren't known until now
self.apply.outputs = self.rnn.apply.outputs
self.compute_initial_state.outputs = self.rnn.apply.outputs
def __init__(self, hidden_dim, cropper, attention_state_name,
hyperparameters, **kwargs):
# we're no longer a brick, but we still need to make sure we
# initialize everything
self.children = []
self.rnn = bricks.RecurrentStack(
[
bricks.LSTM(activation=bricks.Tanh(), dim=hidden_dim),
bricks.LSTM(activation=bricks.Tanh(), dim=hidden_dim)
],
weights_init=initialization.NormalizedInitialization(
initialization.IsotropicGaussian()),
biases_init=initialization.Constant(0))
# name of the RNN state that determines the parameters of the next glimpse
self.attention_state_name = attention_state_name
self.cropper = cropper
self.construct_locator(**hyperparameters)
self.construct_merger(**hyperparameters)
self.embedder = bricks.Linear(name="embedder",
input_dim=self.response_mlp.output_dim,
output_dim=self.rnn.get_dim("inputs"),
use_bias=True,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0))
self.children.extend([self.rnn, self.cropper, self.embedder])
def construct_locator(self, locate_mlp_spec, n_spatial_dims,
location_std, scale_std, batch_normalize,
**kwargs):
self.n_spatial_dims = n_spatial_dims
self.locate_mlp = masonry.construct_mlp(
name="locate_mlp",
input_dim=self.get_dim(self.attention_state_name),
hidden_dims=locate_mlp_spec,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0),
batch_normalize=batch_normalize)
self.theta_from_area = bricks.Linear(
input_dim=self.locate_mlp.output_dim,
output_dim=2*n_spatial_dims,
name="theta_from_area",
# normalize columns because the fan-in is large
weights_init=initialization.NormalizedInitialization(
initialization.IsotropicGaussian()),
# initialize location biases to zero and scale biases to one
# so the model will zoom in by default
biases_init=initialization.Constant(np.array(
[0.] * n_spatial_dims + [1.] * n_spatial_dims)))
self.T_rng = theano.sandbox.rng_mrg.MRG_RandomStreams(12345)
self.location_std = location_std
self.scale_std = scale_std
self.children.extend([
self.locate_mlp,
self.theta_from_area])
def construct_merger(self, n_spatial_dims, n_channels, patch_shape,
patch_cnn_spec, patch_mlp_spec, merge_mlp_spec,
response_mlp_spec, batch_normalize,
batch_normalize_patch, task_name, hyperparameters,
**kwargs):
# construct patch interpretation network
patch_transforms = []
if task_name == "featurelevel_ucf101":
n_channels = 512 + 4096
shape = self.cropper.output_shape
else:
if patch_cnn_spec == "pretrained":
import pretrained
patch_transforms.append(
pretrained.get_patch_transform(**hyperparameters))
shape = patch_transforms[-1].get_dim("output")
elif patch_cnn_spec:
patch_transforms.append(
masonry.construct_cnn(
name="patch_cnn",
layer_specs=patch_cnn_spec,
input_shape=patch_shape,
n_channels=n_channels,
batch_normalize=batch_normalize_patch))
shape = patch_transforms[-1].get_dim("output")
patch_transforms.append(bricks.FeedforwardFlattener(input_shape=shape))
if patch_mlp_spec:
patch_transforms.append(
masonry.construct_mlp(
name="patch_mlp",
hidden_dims=patch_mlp_spec,
input_dim=patch_transforms[-1].output_dim,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0),
batch_normalize=batch_normalize_patch))
self.patch_transform = bricks.FeedforwardSequence(
[brick.apply for brick in patch_transforms], name="ffs")
# construct theta interpretation network
self.merge_mlp = masonry.construct_mlp(
name="merge_mlp",
input_dim=2 * n_spatial_dims,
hidden_dims=merge_mlp_spec,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0),
batch_normalize=batch_normalize)
self.response_mlp = masonry.construct_mlp(
name="response_mlp",
hidden_dims=response_mlp_spec,
input_dim=self.patch_transform.output_dim +
self.merge_mlp.output_dim,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0),
batch_normalize=batch_normalize)
self.children.extend(
[self.patch_transform, self.merge_mlp, self.response_mlp])
def construct_cnn_layer(name, layer_spec, conv_module, ndim, batch_normalize):
type_ = layer_spec.pop("type", "conv")
if type_ == "pool":
layer = conv_module.MaxPooling(
name=name,
pooling_size=layer_spec.pop("size", (1, ) * ndim),
step=layer_spec.pop("step", (1, ) * ndim))
elif type_ == "conv":
border_mode = layer_spec.pop("border_mode", (0, ) * ndim)
if not isinstance(border_mode, basestring):
# conv bricks barf on list-type shape arguments :/
border_mode = tuple(border_mode)
activation = bricks.NormalizedActivation(
name="activation", batch_normalize=batch_normalize)
layer = conv_module.ConvolutionalActivation(
name=name,
activation=activation.apply,
filter_size=tuple(layer_spec.pop("size", (1, ) * ndim)),
step=tuple(layer_spec.pop("step", (1, ) * ndim)),
num_filters=layer_spec.pop("num_filters", 1),
border_mode=border_mode,
# our activation function will handle the bias
use_bias=False)
# sigh. really REALLY do not use biases
layer.convolution.use_bias = False
layer.convolution.weights_init = initialization.ConvolutionalInitialization(
initialization.Orthogonal())
layer.convolution.biases_init = initialization.Constant(0)
if layer_spec:
logger.warn("ignoring unknown layer specification keys [%s]" %
" ".join(layer_spec.keys()))
return layer
def __init__(self, input_dim, n_classes, batch_normalize):
self.input_dim = input_dim
self.n_classes = n_classes
self.mlp = masonry.construct_mlp(
name="mlp",
activations=[None, bricks.Identity()],
input_dim=input_dim,
hidden_dims=[input_dim / 2, self.n_classes],
batch_normalize=batch_normalize,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0))
self.softmax = bricks.Softmax()
self.children = [self.mlp, self.softmax]
def _allocate(self):
arghs = dict(shape=self.shape,
broadcastable=self.broadcastable)
self.sequence = []
if self.batch_normalize:
aarghs = dict(arghs)
if isinstance(self.batch_normalize, collections.Mapping):
aarghs.update(self.batch_normalize)
self.sequence.append(BatchNormalization(**aarghs))
else:
self.sequence.append(SharedShift(
biases_init=initialization.Constant(0),
**arghs))
self.sequence.append(self.activation)
self.children = list(self.sequence)
def __init__(self, input_dim, n_classes, batch_normalize):
self.input_dim = input_dim
self.n_classes = n_classes
# TODO: use TensorLinear or some such
self.emitters = [
masonry.construct_mlp(
activations=[None, bricks.Identity()],
input_dim=input_dim,
hidden_dims=[input_dim/2, n],
name="mlp_%i" % i,
batch_normalize=batch_normalize,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0))
for i, n in enumerate(self.n_classes)]
self.softmax = bricks.Softmax()
self.children = self.emitters + [self.softmax]
def construct_mlp(name,
hidden_dims,
input_dim,
batch_normalize,
activations=None,
weights_init=None,
biases_init=None):
if not hidden_dims:
return bricks.FeedforwardIdentity(dim=input_dim)
if not activations:
activations = [bricks.Rectifier() for dim in hidden_dims]
elif not isinstance(activations, collections.Iterable):
activations = [activations] * len(hidden_dims)
assert len(activations) == len(hidden_dims)
if not weights_init:
weights_init = initialization.Orthogonal()
if not biases_init:
biases_init = initialization.Constant(0)
dims = [input_dim] + hidden_dims
wrapped_activations = [
bricks.NormalizedActivation(shape=[hidden_dim],
name="activation_%i" % i,
batch_normalize=batch_normalize,
activation=activation)
for i, (hidden_dim,
activation) in enumerate(zip(hidden_dims, activations))
]
mlp = bricks.MLP(
name=name,
activations=wrapped_activations,
# biases are handled by our activation function
use_bias=False,
dims=dims,
weights_init=weights_init,
biases_init=biases_init)
return mlp
def construct_merger(self, n_spatial_dims, n_channels,
patch_shape, response_dim, patch_cnn_spec,
patch_mlp_spec, merge_mlp_spec,
response_mlp_spec, batch_normalize,
batch_normalize_patch, **kwargs):
# construct patch interpretation network
patch_transforms = []
if patch_cnn_spec:
patch_transforms.append(masonry.construct_cnn(
name="patch_cnn",
layer_specs=patch_cnn_spec,
input_shape=patch_shape,
n_channels=n_channels,
batch_normalize=batch_normalize_patch))
shape = patch_transforms[-1].get_dim("output")
else:
shape = (n_channels,) + tuple(patch_shape)
patch_transforms.append(bricks.FeedforwardFlattener(input_shape=shape))
if patch_mlp_spec:
patch_transforms.append(masonry.construct_mlp(
name="patch_mlp",
hidden_dims=patch_mlp_spec,
input_dim=patch_transforms[-1].output_dim,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0),
batch_normalize=batch_normalize_patch))
self.patch_transform = bricks.FeedforwardSequence(
[brick.apply for brick in patch_transforms], name="ffs")
# construct theta interpretation network
self.merge_mlp = masonry.construct_mlp(
name="merge_mlp",
input_dim=2*n_spatial_dims,
hidden_dims=merge_mlp_spec,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0),
batch_normalize=batch_normalize)
# construct what-where merger network
self.response_merge = bricks.Merge(
input_names="area patch".split(),
input_dims=[self.merge_mlp.output_dim,
self.patch_transform.output_dim],
output_dim=response_dim,
prototype=bricks.Linear(
use_bias=False,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0)),
child_prefix="response_merge")
self.response_merge_activation = bricks.NormalizedActivation(
shape=[response_dim],
name="response_merge_activation",
batch_normalize=batch_normalize)
self.response_mlp = masonry.construct_mlp(
name="response_mlp",
hidden_dims=response_mlp_spec,
input_dim=response_dim,
weights_init=initialization.Orthogonal(),
biases_init=initialization.Constant(0),
batch_normalize=batch_normalize)
self.children.extend([
self.response_merge_activation,
self.response_merge,
self.patch_transform,
self.merge_mlp,
self.response_mlp])
def _initialize(self):
zero, one = initialization.Constant(0.), initialization.Constant(1.)
zero.initialize(self.population_stats["mean"], rng=self.rng)
one.initialize(self.population_stats["var"], rng=self.rng)
one.initialize(self.gamma, rng=self.rng)
zero.initialize(self.beta, rng=self.rng)