def scale(self, x_obj, w_scale, w_trans):
# removes the last dimension
obj = tf.squeeze(x_obj)
w_scale = tf.expand_dims(w_scale, -1)
w_trans_x = tf.expand_dims(w_trans[:, 0], -1)
w_trans_y = tf.expand_dims(w_trans[:, 1], -1)
w_trans_z = tf.expand_dims(w_trans[:, 2], -1)
# !!! note that in their implementation for images, y and x are swiiched,
# in out implementation it as well: [batch, y, x, z]
# transform the x and y dim first
s_xy = tf.matmul(w_scale,
tf.constant([[1, 0, 0, 0, 1, 0]], dtype=tf.float32))
t_xy = tf.matmul(
w_trans_x,
tf.constant([[0, 0, 1, 0, 0, 0]], dtype=tf.float32)) + tf.matmul(
w_trans_y, tf.constant([[0, 0, 0, 0, 0, 1]], dtype=tf.float32))
T_xy = s_xy + t_xy
transformed_xy = stn(obj, T_xy)
# reshape the obj so that it starts with z dim: [batch, x, z, y]
transposed_transformed_xy = tf.transpose(transformed_xy, [0, 2, 3, 1])
# transform the z dim
s_zx = tf.matmul(
w_scale, tf.constant(
[[1, 0, 0, 0, 0, 0]], dtype=tf.float32)) + tf.matmul(
tf.ones([self.batch_size, 1]),
tf.constant([[0, 0, 0, 0, 1, 0]], dtype=tf.float32))
t_zx = tf.matmul(w_trans_z,
tf.constant([[0, 0, 1, 0, 0, 0]], dtype=tf.float32))
T_zx = s_zx + t_zx
transformed_zxy = stn(transposed_transformed_xy, T_zx)
# reshape to the original order: [batch, y, x, z]
transformed_xyz = tf.transpose(transformed_zxy, [0, 3, 1, 2])
# add the last dimension back
transformed_xyz = tf.expand_dims(transformed_xyz, -1)
print(transformed_xyz)
return transformed_xyz
def build_convnet():
# localization network
conv1_loc = Conv2D(X, 1, 5, 32, name='conv1_loc')
pool1_loc = MaxPooling2D(conv1_loc, use_relu=True, name='pool1_loc')
conv2_loc = Conv2D(pool1_loc, 32, 5, 64, name='conv2_loc')
pool2_loc = MaxPooling2D(conv2_loc, use_relu=True, name='pool2_loc')
pool2_loc_flat, pool2_loc_size = Flatten(pool2_loc)
fc1_loc = Dense(pool2_loc_flat,
pool2_loc_size,
2048,
use_relu=False,
name='fc1_loc')
fc2_loc = Dense(fc1_loc, 2048, 512, use_relu=True, name='fc2_loc')
fc3_loc = Dense(fc2_loc,
512,
6,
use_relu=False,
trans=True,
name='fc3_loc')
print('fc3_loc: {}'.format(fc3_loc.get_shape()))
# spatial transformer
h_trans = stn(X, fc3_loc)
print('h_trans: {}'.format(h_trans.get_shape()))
# convnet
conv1 = Conv2D(X, 1, 5, 32, name='conv1')
bn1 = BatchNormalization(conv1, phase, name='bn1')
pool1 = MaxPooling2D(bn1, use_relu=True, name='pool1')
conv2 = Conv2D(pool1, 32, 5, 64, name='conv2')
bn2 = BatchNormalization(conv2, phase, name='bn2')
pool2 = MaxPooling2D(bn2, use_relu=True, name='pool2')
conv3 = Conv2D(pool2, 64, 3, 128, name='conv3')
bn3 = BatchNormalization(conv3, phase, name='bn3')
pool3 = MaxPooling2D(bn3, use_relu=True, name='pool3')
pool3_flat, pool3_size = Flatten(pool3)
fc1 = Dense(pool3_flat, pool3_size, 2048, use_relu=False, name='fc1')
bn4 = BatchNormalization(fc1, phase, use_relu=True, name='bn4')
fc2 = Dense(bn4, 2048, 512, use_relu=False, name='fc2')
bn5 = BatchNormalization(fc2, phase, use_relu=True, name='bn5')
logits = Dense(bn5, 512, num_classes, name='fc3', use_relu=False)
return h_trans, logits
def focal_loss(target_tensor, theta, org, weights=None, alpha=0.25, gamma=2):
r"""Compute focal loss for predictions.
Multi-labels Focal loss formula:
FL = -alpha * (z-p)^gamma * log(p) -(1-alpha) * p^gamma * log(1-p)
,which alpha = 0.25, gamma = 2, p = sigmoid(x), z = target_tensor.
Args:
prediction_tensor: A float tensor of shape [batch_size, num_anchors,
num_classes] representing the predicted logits for each class
target_tensor: A float tensor of shape [batch_size, num_anchors,
num_classes] representing one-hot encoded classification targets
weights: A float tensor of shape [batch_size, num_anchors]
alpha: A scalar tensor for focal loss alpha hyper-parameter
gamma: A scalar tensor for focal loss gamma hyper-parameter
Returns:
loss: A (scalar) tensor representing the value of the loss function
"""
prediction_tensor = stn(org, theta)
prediction_tensor = tf.to_int32(prediction_tensor > 0.5)
prediction_tensor = tf.one_hot(prediction_tensor, depth=2)
prediction_tensor = tf.dtypes.cast(prediction_tensor, tf.float32)
# target_tensor = tf.convert_to_tensor(target_tensor, tf.int32)
target_tensor = tf.dtypes.cast(target_tensor, tf.int32)
target_tensor = tf.one_hot(target_tensor, depth=2)
target_tensor = tf.dtypes.cast(target_tensor, tf.float32)
prediction_tensor = tf.convert_to_tensor(prediction_tensor, tf.float32)
target_tensor = tf.convert_to_tensor(target_tensor, tf.float32)
print("Target tensor shape", target_tensor.get_shape().as_list())
print("Prediction tensor shape", prediction_tensor.get_shape().as_list())
sigmoid_p = tf.nn.sigmoid(prediction_tensor)
zeros = array_ops.zeros_like(sigmoid_p, dtype=sigmoid_p.dtype)
# For poitive prediction, only need consider front part loss, back part is 0;
# target_tensor > zeros <=> z=1, so poitive coefficient = z - p.
pos_p_sub = array_ops.where(target_tensor > zeros,
target_tensor - sigmoid_p, zeros)
# For negative prediction, only need consider back part loss, front part is 0;
# target_tensor > zeros <=> z=1, so negative coefficient = 0.
neg_p_sub = array_ops.where(target_tensor > zeros, zeros, sigmoid_p)
per_entry_cross_ent = - alpha * (pos_p_sub ** gamma) * tf.log(tf.clip_by_value(sigmoid_p, 1e-8, 1.0)) \
- (1 - alpha) * (neg_p_sub ** gamma) * tf.log(tf.clip_by_value(1.0 - sigmoid_p, 1e-8, 1.0))
return tf.reduce_sum(per_entry_cross_ent)
def focal_loss_(labels, theta, org, gamma=2.0, alpha=4.0):
logits = stn(org, theta)
# logits = (0.5 > logits).float() * 1
logits = tf.cast(logits + 0.5, tf.float32)
# logits = tf.one_hot(logits, depth=2)
epsilon = 1.e-9
labels = tf.convert_to_tensor(labels, tf.float32)
logits = tf.convert_to_tensor(logits, tf.float32)
logits = tf.nn.softmax(logits, dim=-1)
model_out = tf.add(logits, epsilon)
ce = tf.multiply(labels, -tf.log(model_out))
weight = tf.multiply(labels, tf.pow(tf.subtract(1., model_out), gamma))
fl = tf.multiply(alpha, tf.multiply(weight, ce))
reduced_fl = tf.reduce_max(fl, axis=1)
return reduced_fl
def build_convnet(): # localization network conv1_loc = Conv2D(X, 1, 5, 32, name='conv1_loc') pool1_loc = MaxPooling2D(conv1_loc, use_relu=True, name='pool1_loc') conv2_loc = Conv2D(pool1_loc, 32, 5, 64, name='conv2_loc') pool2_loc = MaxPooling2D(conv2_loc, use_relu=True, name='pool2_loc') pool2_loc_flat, pool2_loc_size = Flatten(pool2_loc) fc1_loc = Dense(pool2_loc_flat, pool2_loc_size, 2048, use_relu=False, name='fc1_loc') fc2_loc = Dense(fc1_loc, 2048, 512, use_relu=True, name='fc2_loc') fc3_loc = Dense(fc2_loc, 512, 6, use_relu=False, trans=True, name='fc3_loc') # spatial transformer h_trans = stn(X, fc3_loc) # convnet conv1 = Conv2D(X, 1, 5, 32, name='conv1') bn1 = BatchNormalization(conv1, phase, name='bn1') pool1 = MaxPooling2D(bn1, use_relu=True, name='pool1') conv2 = Conv2D(pool1, 32, 5, 64, name='conv2') bn2 = BatchNormalization(conv2, phase, name='bn2') pool2 = MaxPooling2D(bn2, use_relu=True, name='pool2') conv3 = Conv2D(pool2, 64, 3, 128, name='conv3') bn3 = BatchNormalization(conv3, phase, name='bn3') pool3 = MaxPooling2D(bn3, use_relu=True, name='pool3') pool3_flat, pool3_size = Flatten(pool3) fc1 = Dense(pool3_flat, pool3_size, 2048, use_relu=False, name='fc1') bn4 = BatchNormalization(fc1, phase, use_relu=True, name='bn4') fc2 = Dense(bn4, 2048, 512, use_relu=False, name='fc2') bn5 = BatchNormalization(fc2, phase, use_relu=True, name='bn5') logits = Dense(bn5, 512, num_classes, name='fc3', use_relu=False) return h_trans, logits
def classification_loss(labels, theta, org):
logits = stn(org, theta)
n_class = 1
flat_logits = tf.reshape(logits, [-1])
flat_labels = tf.reshape(labels, [-1])
# print(tf.shape(flat_logits))
# print(tf.shape(flat_labels))
loss = tf.losses.mean_squared_error(flat_labels, flat_logits)
# flat_logits = tf.multiply(flat_logits, 255.0)
# flat_labels = tf.multiply(flat_labels, 255.0)
# flat_logits = tf.dtypes.cast(flat_logits, dtype=tf.int32)
# flat_labels = tf.dtypes.cast(flat_labels, dtype=tf.int32)
# accuracy, update_op = tf.metrics.accuracy(labels=flat_labels[0],
# predictions=flat_logits[0])
# return loss, accuracy
return loss
def main():
# load the data
print("Loading the data...")
X_train, y_train, X_test, y_test, X_valid, y_valid = load_data(root_dir)
# sanity check dimensions
# print("Train: {}".format(X_train.shape))
# print("Test: {}".format(X_test.shape))
# print("Valid: {}".format(X_valid.shape))
# let's view a small sample
if VIEW:
mask = np.arange(9)
gd_truth = np.argmax(y_train[mask], axis=1)
sample = X_train.squeeze()[mask]
plot_images(sample, gd_truth)
if SAMPLE:
mask = np.arange(500)
X_train = X_train[mask]
y_train = y_train[mask]
num_train = X_train.shape[0]
gd_truth = np.argmax(y_train, axis=1)
# let's check the frequencies of each class
# plt.hist(gd_truth, bins=num_classes)
# plt.title("Ground Truth Labels")
# plt.xlabel("Class")
# plt.ylabel("Frequency")
# plt.show()
print("Building ConvNet...")
conv1_loc = Conv2D(X, 1, 5, 32, name='conv1_loc')
pool1_loc = MaxPooling2D(conv1_loc, use_relu=True, name='pool1_loc')
conv2_loc = Conv2D(pool1_loc, 32, 5, 64, name='conv2_loc')
pool2_loc = MaxPooling2D(conv2_loc, use_relu=True, name='pool2_loc')
pool2_loc_flat, pool2_loc_size = Flatten(pool2_loc)
fc1_loc = Dense(pool2_loc_flat, pool2_loc_size, 2048, use_relu=False, name='fc1_loc')
fc2_loc = Dense(fc1_loc, 2048, 512, use_relu=True, name='fc2_loc')
fc3_loc = Dense(fc2_loc, 512, 6, use_relu=False, trans=True, name='fc3_loc')
# spatial transformer
h_trans = stn(X, fc3_loc, out_dims=(H, W))
# convnet
conv1 = Conv2D(h_trans, 1, 5, 32, name='conv1')
bn1 = BatchNormalization(conv1, phase, name='bn1')
pool1 = MaxPooling2D(bn1, use_relu=True, name='pool1')
conv2 = Conv2D(pool1, 32, 5, 64, name='conv2')
bn2 = BatchNormalization(conv2, phase, name='bn2')
pool2 = MaxPooling2D(bn2, use_relu=True, name='pool2')
conv3 = Conv2D(pool2, 64, 3, 128, name='conv3')
bn3 = BatchNormalization(conv3, phase, name='bn3')
pool3 = MaxPooling2D(bn3, use_relu=True, name='pool3')
pool3_flat, pool3_size = Flatten(pool3)
fc1 = Dense(pool3_flat, pool3_size, 2048, use_relu=False, name='fc1')
bn4 = BatchNormalization(fc1, phase, use_relu=True, name='bn4')
fc2 = Dense(bn4, 2048, 512, use_relu=False, name='fc2')
bn5 = BatchNormalization(fc2, phase, use_relu=True, name='bn5')
logits = Dense(bn5, 512, num_classes, name='fc3', use_relu=False)
# define cost function
cross_entropy = tf.nn.softmax_cross_entropy_with_logits(logits=logits, labels=y)
loss = tf.reduce_mean(cross_entropy)
# define optimizer
global_step = tf.Variable(initial_value=0, name='global_step', trainable=False)
optimizer = tf.train.AdamOptimizer(learning_rate=learning_rate).minimize(loss, global_step)
# define accuracy
correct_pred = tf.equal(tf.argmax(logits, 1), tf.argmax(y, 1))
accuracy = tf.reduce_mean(tf.cast(correct_pred, tf.float32))
# define saver object for storing and retrieving checkpoints
saver = tf.train.Saver()
if not os.path.exists(save_dir):
os.makedirs(save_dir)
save_path = os.path.join(save_dir, 'best_validation') # path for the checkpoint file
total_batch = int(np.ceil(num_train / float(batch_size)))
num_iterations = num_epochs * total_batch
global best_validation_accuracy
global last_improvement
global require_improvement
# create summary for loss and acc
tf.summary.scalar('train_loss', loss)
tf.summary.scalar('train_accuracy', accuracy)
summary_op = tf.summary.merge_all()
if not os.path.exists(logs_dir):
os.makedirs(logs_dir)
logs_path = os.path.join(logs_dir, 'cluttered_mnist/')
if not os.path.exists(vis_path):
os.makedirs(vis_path)
with tf.Session() as sess:
if RESTORE:
# restore checkpoint if it exists
try:
print("Trying to restore last checkpoint...")
last_chk_path = tf.train.latest_checkpoint(checkpoint_dir=save_dir)
saver.restore(sess, save_path=last_chk_path)
print("Restored checkpoint from: ", last_chk_path)
except:
print("Failed to restore checkpoint. Initializing variables instead.")
sess.run(tf.global_variables_initializer())
else:
sess.run(tf.global_variables_initializer())
# for tensorboard viewing
writer = tf.summary.FileWriter(logs_path, graph=tf.get_default_graph())
# for visualization purposes
fig = plt.figure()
if MODE == 'train':
tic = time.time()
print("Training on {} samples, validating on {} samples".format(len(X_train), len(X_valid)))
iter_per_epoch, batch_indices = generate_batch_indices(X_train)
batch_indices = batch_indices * num_epochs
epoch_num = 0
for i in range(num_iterations):
# grab the batch index from list
idx = batch_indices[i]
mask = np.arange(idx[0], idx[1])
# slice into batches
batch_X_train, batch_y_train = X_train[mask], y_train[mask]
# create feed dict
train_feed_dict = {X: batch_X_train, y: batch_y_train, phase: True}
i_global, _ = sess.run([global_step, optimizer], feed_dict=train_feed_dict)
if (i_global % display_step == 0) or (i == num_iterations - 1):
# calculate loss and accuracy on training batch
train_batch_loss, train_batch_acc, train_summary = sess.run([loss, accuracy, summary_op], feed_dict=train_feed_dict)
writer.add_summary(train_summary, i_global)
# calculate loss and accuracy on validation batch
valid_batch_loss, valid_batch_acc = validate_acc_loss(sess, loss, accuracy, X_valid, y_valid)
# check to see if there's an improvement
improved_str = ''
if valid_batch_acc > best_validation_accuracy:
best_validation_accuracy = valid_batch_acc
last_improvement = i_global
saver.save(sess=sess, save_path=save_path+str(best_validation_accuracy), global_step=i_global)
improved_str = '*'
print("Iter: {}/{} - loss: {:.4f} - acc: {:.4f} - val_loss: {:.4f} - val_acc: {:.4f} - {}".format(i_global,
num_iterations, train_batch_loss, train_batch_acc, valid_batch_loss, valid_batch_acc, improved_str))
# if no improvement in a while, stop training
if i_global - last_improvement > require_improvement:
print("No improvement found in a while, stopping optimization.")
break
# for plotting
if i_global == 1:
print("Plotting input imgs...")
input_imgs = batch_X_train[:9]
input_imgs = np.reshape(input_imgs, [-1, 60, 60])
plt.clf()
for j in range(9):
plt.subplot(3, 3, j+1)
plt.imshow(input_imgs[j], cmap='gray')
plt.axis('off')
fig.canvas.draw()
plt.savefig(vis_path + 'epoch_0.png', bbox_inches='tight')
# plotting
thetas = sess.run(h_trans, feed_dict={X: batch_X_train, phase: True})
thetas = thetas[0:9].squeeze()
plt.clf()
for j in range(9):
plt.subplot(3, 3, j+1)
plt.imshow(thetas[j], cmap='gray')
plt.axis('off')
fig.canvas.draw()
plt.savefig(vis_path + 'epoch_' + str(i_global) + '.png', bbox_inches='tight')
toc = time.time()
print("Time: {:.2f}s".format(toc-tic))
print("Best valid acc: {}".format(best_validation_accuracy))
else:
test_accuracy = test_acc(sess, accuracy, X_test, y_test)
print("Test Set Accuracy: {}".format(test_accuracy))
def spatial_transformer_layer(name_scope,
input_tensor,
img_size,
kernel_size,
pooling=None,
strides=[1, 1, 1, 1],
pool_strides=[1, 1, 1, 1],
activation=tf.nn.relu,
use_bn=False,
use_mvn=False,
is_training=False,
use_lrn=False,
keep_prob=1.0,
dropout_maps=False,
init_opt=0,
bias_init=0.1):
"""
Define spatial transformer network layer
Args:
scope_or_name: `string` or `VariableScope`, the scope to open.
inputs: `4-D Tensor`, it is assumed that `inputs` is shaped `[batch_size, Y, X, Z]`.
kernel: `4-D Tensor`, [kernel_height, kernel_width, in_channels, out_channels] kernel.
img_size: 2D array, [image_width. image_height]
bias: `1-D Tensor`, [out_channels] bias.
strides: list of `ints`, length 4, the stride of the sliding window for each dimension of `inputs`.
activation: activation function to be used (default: `tf.nn.relu`).
use_bn: `bool`, whether or not to include batch normalization in the layer.
is_training: `bool`, whether or not the layer is in training mode. This is only used if `use_bn` == True.
use_lrn: `bool`, whether or not to include local response normalization in the layer.
keep_prob: `double`, dropout keep prob.
dropout_maps: `bool`, If true whole maps are dropped or not, otherwise single elements.
padding: `string` from 'SAME', 'VALID'. The type of padding algorithm used in the convolution.
Returns:
`4-D Tensor`, has the same type `inputs`.
"""
img_height = img_size[0]
img_width = img_size[1]
with tf.variable_scope(name_scope):
if init_opt == 0:
stddev = np.sqrt(2 / (kernel_size[0] * kernel_size[1] *
kernel_size[2] * kernel_size[3]))
elif init_opt == 1:
stddev = 5e-2
elif init_opt == 2:
stddev = min(
np.sqrt(2.0 /
(kernel_size[0] * kernel_size[1] * kernel_size[2])),
5e-2)
kernel = tf.get_variable(
'weights',
kernel_size,
initializer=tf.random_normal_initializer(stddev=stddev))
conv = tf.nn.conv2d(input_tensor,
kernel,
strides,
padding='SAME',
name='conv')
bias = tf.get_variable(
'bias',
kernel_size[3],
initializer=tf.constant_initializer(value=bias_init))
output_tensor = tf.nn.bias_add(conv, bias, name='pre_activation')
if activation:
output_tensor = activation(output_tensor, name='activation')
if use_lrn:
output_tensor = tf.nn.local_response_normalization(
output_tensor, name='local_responsive_normalization')
if dropout_maps:
conv_shape = tf.shape(output_tensor)
n_shape = tf.stack([conv_shape[0], 1, 1, conv_shape[3]])
output_tensor = tf.nn.dropout(output_tensor,
keep_prob=keep_prob,
noise_shape=n_shape)
else:
output_tensor = tf.nn.dropout(output_tensor, keep_prob=keep_prob)
if pooling:
output_tensor = tf.nn.max_pool(output_tensor,
ksize=pooling,
strides=pool_strides,
padding='VALID')
output_tensor = tf.contrib.layers.flatten(output_tensor)
output_tensor = tf.contrib.layers.fully_connected(
output_tensor, 64, scope='fully_connected_layer_1')
output_tensor = tf.nn.tanh(output_tensor)
output_tensor = tf.contrib.layers.fully_connected(
output_tensor, 6, scope='fully_connected_layer_2')
output_tensor = tf.nn.tanh(output_tensor)
stn_output = stn(input_fmap=input_tensor,
theta=output_tensor,
out_dims=(img_height, img_width))
return stn_output, output_tensor
# theta = graph.get_tensor_by_name("network/stn_0/fully_connected_layer_2/weights:0")
input_tensor = graph.get_tensor_by_name("train_inputs:0")
idx = 0
for i in range(0, 2):
batch_x, batch_y = data_provider.get_data('validation')
train_feed_dict = {
input_tensor: batch_x,
}
# theta = tf.eye(3, batch_shape=[4])
# theta = tf.eye(num_rows=1, num_columns=9, batch_shape=[4])
# theta = tf.reshape(theta, ([4, -1]))
# print("Theta shape, ", theta.get_shape().as_list())
logits = stn(input_tensor, theta)
imgs = sess.run([logits], feed_dict=train_feed_dict)
imgs = np.array(imgs)
batch_y = np.array(batch_y)
y_pred = imgs.flatten()
y = batch_y.flatten()
summation = 0
n = len(y)
for i in range(0, n):
difference = y[i] - y_pred[i]
squared_difference = difference**2
summation = summation + squared_difference
MSE = summation / n
def main():
# load the data
print("Loading the data...")
X_train, y_train, X_test, y_test, X_valid, y_valid = load_data(root_dir)
# saniy check dimensions
# print("Train: {}".format(X_train.shape))
# print("Test: {}".format(X_test.shape))
# print("Valid: {}".format(X_valid.shape))
# let's view a small sample
if VIEW:
mask = np.arange(9)
gd_truth = np.argmax(y_train[mask], axis=1)
sample = X_train.squeeze()[mask]
plot_images(sample, gd_truth)
if SAMPLE:
mask = np.arange(500)
X_train = X_train[mask]
y_train = y_train[mask]
num_train = X_train.shape[0]
gd_truth = np.argmax(y_train, axis=1)
# # let's check the frequencies of each class
# plt.hist(gd_truth, bins=num_classes)
# plt.title("Ground Truth Labels")
# plt.xlabel("Class")
# plt.ylabel("Frequency")
# plt.show()
print("Building ConvNet...")
conv1_loc = Conv2D(X, 1, 5, 32, name='conv1_loc')
pool1_loc = MaxPooling2D(conv1_loc, use_relu=True, name='pool1_loc')
conv2_loc = Conv2D(pool1_loc, 32, 5, 64, name='conv2_loc')
pool2_loc = MaxPooling2D(conv2_loc, use_relu=True, name='pool2_loc')
pool2_loc_flat, pool2_loc_size = Flatten(pool2_loc)
fc1_loc = Dense(pool2_loc_flat, pool2_loc_size, 2048, use_relu=False, name='fc1_loc')
fc2_loc = Dense(fc1_loc, 2048, 512, use_relu=True, name='fc2_loc')
fc3_loc = Dense(fc2_loc, 512, 6, use_relu=False, trans=True, name='fc3_loc')
# spatial transformer
h_trans = stn(X, fc3_loc)
# convnet
conv1 = Conv2D(X, 1, 5, 32, name='conv1')
bn1 = BatchNormalization(conv1, phase, name='bn1')
pool1 = MaxPooling2D(bn1, use_relu=True, name='pool1')
conv2 = Conv2D(pool1, 32, 5, 64, name='conv2')
bn2 = BatchNormalization(conv2, phase, name='bn2')
pool2 = MaxPooling2D(bn2, use_relu=True, name='pool2')
conv3 = Conv2D(pool2, 64, 3, 128, name='conv3')
bn3 = BatchNormalization(conv3, phase, name='bn3')
pool3 = MaxPooling2D(bn3, use_relu=True, name='pool3')
pool3_flat, pool3_size = Flatten(pool3)
fc1 = Dense(pool3_flat, pool3_size, 2048, use_relu=False, name='fc1')
bn4 = BatchNormalization(fc1, phase, use_relu=True, name='bn4')
fc2 = Dense(bn4, 2048, 512, use_relu=False, name='fc2')
bn5 = BatchNormalization(fc2, phase, use_relu=True, name='bn5')
logits = Dense(bn5, 512, num_classes, name='fc3', use_relu=False)
# define cost function
cross_entropy = tf.nn.softmax_cross_entropy_with_logits(logits=logits, labels=y)
loss = tf.reduce_mean(cross_entropy)
# define optimizer
global_step = tf.Variable(initial_value=0, name='global_step', trainable=False)
optimizer = tf.train.AdamOptimizer(learning_rate=learning_rate).minimize(loss, global_step)
# define accuracy
correct_pred = tf.equal(tf.argmax(logits, 1), tf.argmax(y, 1))
accuracy = tf.reduce_mean(tf.cast(correct_pred, tf.float32))
# define saver object for storing and retrieving checkpoints
saver = tf.train.Saver()
if not os.path.exists(save_dir):
os.makedirs(save_dir)
save_path = os.path.join(save_dir, 'best_validation') # path for the checkpoint file
total_batch = int(np.ceil(num_train / float(batch_size)))
num_iterations = num_epochs * total_batch
global best_validation_accuracy
global last_improvement
global require_improvement
# create summary for loss and acc
tf.summary.scalar('train_loss', loss)
tf.summary.scalar('train_accuracy', accuracy)
summary_op = tf.summary.merge_all()
if not os.path.exists(logs_dir):
os.makedirs(logs_dir)
logs_path = os.path.join(logs_dir, 'cluttered_mnist/')
if not os.path.exists(vis_path):
os.makedirs(vis_path)
with tf.Session() as sess:
if RESTORE:
# restore checkpoint if it exists
try:
print("Trying to restore last checkpoint ...")
last_chk_path = tf.train.latest_checkpoint(checkpoint_dir=save_dir)
saver.restore(sess, save_path=last_chk_path)
print("Restored checkpoint from:", last_chk_path)
except:
print("Failed to restore checkpoint. Initializing variables instead.")
sess.run(tf.global_variables_initializer())
else:
sess.run(tf.global_variables_initializer())
# for tensorboard viewing
writer = tf.summary.FileWriter(logs_path, graph=tf.get_default_graph())
# for visualization purposes
fig = plt.figure()
if MODE == 'train':
tic = time.time()
print("Training on {} samples, validating on {} samples".format(len(X_train), len(X_valid)))
iter_per_epoch, batch_indices = generate_batch_indices(X_train)
batch_indices = batch_indices * num_epochs
epoch_num = 0
for i in range(num_iterations):
# grab the batch index from list
idx = batch_indices[i]
mask = np.arange(idx[0], idx[1])
# slice into batches
batch_X_train, batch_y_train = X_train[mask], y_train[mask]
# create feed dict
train_feed_dict = {X: batch_X_train, y: batch_y_train, phase: True}
i_global, _ = sess.run([global_step, optimizer], feed_dict=train_feed_dict)
if (i_global % display_step == 0) or (i == num_iterations - 1):
# calculate loss and accuracy on training batch
train_batch_loss, train_batch_acc, train_summary = sess.run([loss, accuracy, summary_op], feed_dict=train_feed_dict)
writer.add_summary(train_summary, i_global)
# calculate loss and accuracy on validation batch
valid_batch_loss, valid_batch_acc = validate_acc_loss(sess, loss, accuracy, X_valid, y_valid)
# check to see if there's an improvement
improved_str = ''
if valid_batch_acc > best_validation_accuracy:
best_validation_accuracy = valid_batch_acc
last_improvement = i_global
saver.save(sess=sess, save_path=save_path+str(best_validation_accuracy), global_step=i_global)
improved_str = '*'
print("Iter: {}/{} - loss: {:.4f} - acc: {:.4f} - val_loss: {:.4f} - val_acc: {:.4f} - {}".format(i_global,
num_iterations, train_batch_loss, train_batch_acc, valid_batch_loss, valid_batch_acc, improved_str))
# if no improvement in a while, stop training
if i_global - last_improvement > require_improvement:
print("No improvement found in a while, stopping optimization.")
break
# for plotting
if i_global == 1:
print("Plotting input imgs...")
input_imgs = batch_X_train[:9]
input_imgs = np.reshape(input_imgs, [-1, 60, 60])
plt.clf()
for j in range(9):
plt.subplot(3, 3, j+1)
plt.imshow(input_imgs[j], cmap='gray')
plt.axis('off')
fig.canvas.draw()
plt.savefig(vis_path + 'epoch_0.png', bbox_inches='tight')
# plotting
thetas = sess.run(h_trans, feed_dict={X: batch_X_train, phase: True})
thetas = thetas[0:9].squeeze()
plt.clf()
for j in range(9):
plt.subplot(3, 3, j+1)
plt.imshow(thetas[j], cmap='gray')
plt.axis('off')
fig.canvas.draw()
plt.savefig(vis_path + 'epoch_' + str(i_global) + '.png', bbox_inches='tight')
toc = time.time()
print("Time: {:.2f}s".format(toc-tic))
print("Best valid acc: {}".format(best_validation_accuracy))
else:
test_accuracy = test_acc(sess, accuracy, X_test, y_test)
print("Test Set Accuracy: {}".format(test_accuracy))