def _build_graph(self):
from tf_utils.layers import conv2d, max_pool, rescale_bilinear, avg_pool
def layer_width(layer: int): # number of channels (features per pixel)
return min([4 * 4**(layer + 1), 64])
input_shape = [None] + list(self.input_shape)
output_shape = input_shape[:3] + [self.class_count]
# Input image and labels placeholders
input = tf.placeholder(tf.float32, shape=input_shape)
target = tf.placeholder(tf.float32, shape=output_shape)
# Downsampled input (to improve speed at the cost of accuracy)
h = rescale_bilinear(input, 0.5)
# Hidden layers
h = conv2d(h, 3, layer_width(0))
h = tf.nn.relu(h)
for l in range(1, self.conv_layer_count):
h = max_pool(h, 2)
h = conv2d(h, 3, layer_width(l))
h = tf.nn.relu(h)
# Pixelwise softmax classification and label upscaling
logits = conv2d(h, 1, self.class_count)
probs = tf.nn.softmax(logits)
probs = tf.image.resize_bilinear(probs, output_shape[1:3])
# Loss
clipped_probs = tf.clip_by_value(probs, 1e-10, 1.0)
ts = lambda x: x[:, :, :, 1:] if self.class0_unknown else x
cost = -tf.reduce_mean(ts(target) * tf.log(ts(clipped_probs)))
# Optimization
optimizer = tf.train.AdamOptimizer(self.learning_rate)
training_step = optimizer.minimize(cost)
# Dense predictions and labels
preds, dense_labels = tf.argmax(probs, 3), tf.argmax(target, 3)
# Other evaluation measures
self._n_accuracy = tf.reduce_mean(
tf.cast(tf.equal(preds, dense_labels), tf.float32))
return AbstractModel.EssentialNodes(
input=input,
target=target,
probs=probs,
loss=cost,
training_step=training_step)
def _build_graph(self, learning_rate, epoch, is_training):
from layers import conv
# Input image and labels placeholders
input_shape = [None] + list(self.input_shape)
output_shape = [None, self.class_count]
input = tf.placeholder(tf.float32, shape=input_shape)
target = tf.placeholder(tf.float32, shape=output_shape)
# Hidden layers
h = layers_exp.rbf_resnet(input,
is_training=is_training,
base_width=self.base_width,
widening_factor=self.widening_factor,
group_lengths=self.group_lengths)
# Global pooling and softmax classification
h = tf.reduce_mean(h, axis=[1, 2], keep_dims=True)
logits = conv(h, 1, self.class_count)
logits = tf.reshape(logits, [-1, self.class_count])
probs = tf.nn.softmax(logits)
# Loss
clipped_probs = tf.clip_by_value(probs, 1e-10, 1.0)
loss = -tf.reduce_mean(target * tf.log(clipped_probs))
# Regularization
w_vars = filter(lambda x: 'weights' in x.name, tf.global_variables())
loss += self.weight_decay * regularization.l2_regularization(w_vars)
# Optimization
optimizer = tf.train.MomentumOptimizer(learning_rate, 0.9)
training_step = optimizer.minimize(loss)
# Dense predictions and labels
preds, dense_labels = tf.argmax(probs, 1), tf.argmax(target, 1)
# Other evaluation measures
accuracy = tf.reduce_mean(
tf.cast(tf.equal(preds, dense_labels), tf.float32))
#writer = tf.summary.FileWriter('logs', self._sess.graph)
return AbstractModel.EssentialNodes(input=input,
target=target,
probs=probs,
loss=loss,
training_step=training_step,
evaluation={'accuracy': accuracy})
def _build_graph(self, learning_rate, epoch, is_training):
from tensorflow.contrib import layers
from tf_utils.layers import conv2d, max_pool, rescale_bilinear, avg_pool, bn_relu
from tf_utils.losses import multiclass_hinge_loss
def get_ortho_penalty():
vars = tf.contrib.framework.get_variables('')
filt = lambda x: 'conv' in x.name and 'weights' in x.name
weight_vars = list(filter(filt, vars))
loss = tf.constant(0.0)
for v in weight_vars:
m = tf.reshape(v, (-1, v.shape[3].value))
d = tf.matmul(
m, m, True) - tf.eye(v.shape[3].value) / v.shape[3].value
loss += tf.reduce_sum(d**2)
return loss
input_shape = [None] + list(self.input_shape)
output_shape = [None, self.class_count]
# Input image and labels placeholders
input = tf.placeholder(tf.float32, shape=input_shape, name='input')
target = tf.placeholder(tf.float32, shape=output_shape, name='target')
# L2 regularization
weight_decay = tf.constant(self.weight_decay, dtype=tf.float32)
# Hidden layers
h = input
with tf.contrib.framework.arg_scope(
[layers.conv2d],
kernel_size=5,
data_format='NHWC',
padding='SAME',
activation_fn=tf.nn.relu,
weights_initializer=layers.variance_scaling_initializer(),
weights_regularizer=layers.l2_regularizer(weight_decay)):
h = layers.conv2d(h, 16, scope='convrelu1')
h = layers.max_pool2d(h, 2, 2, scope='pool1')
h = layers.conv2d(h, 32, scope='convrelu2')
h = layers.max_pool2d(h, 2, 2, scope='pool2')
with tf.contrib.framework.arg_scope(
[layers.fully_connected],
activation_fn=tf.nn.relu,
weights_initializer=layers.variance_scaling_initializer(),
weights_regularizer=layers.l2_regularizer(weight_decay)):
h = layers.flatten(h, scope='flatten3')
h = layers.fully_connected(h, 512, scope='fc3')
self._print_vars()
# Softmax classification
logits = layers.fully_connected(h,
self.class_count,
activation_fn=None,
scope='logits')
probs = tf.nn.softmax(logits, name='probs')
# Loss
mhl = lambda t, lo: 0.1 * multiclass_hinge_loss(t, lo)
sce = tf.losses.softmax_cross_entropy
loss = (mhl if self.use_multiclass_hinge_loss else sce)(target, logits)
loss = loss + tf.reduce_sum(
tf.get_collection(tf.GraphKeys.REGULARIZATION_LOSSES))
if self.ortho_penalty > 0:
loss += self.ortho_penalty * get_ortho_penalty()
# Optimization
optimizer = tf.train.AdamOptimizer(learning_rate)
training_step = optimizer.minimize(loss)
# Dense predictions and labels
preds, dense_labels = tf.argmax(probs, 1), tf.argmax(target, 1)
# Other evaluation measures
accuracy = tf.reduce_mean(
tf.cast(tf.equal(preds, dense_labels), tf.float32))
return AbstractModel.EssentialNodes(input=input,
target=target,
probs=probs,
loss=loss,
training_step=training_step,
evaluation={'accuracy': accuracy})