def process_one_label_dataset(label_ds, config, output_index=None):
"""process one-label data set."""
logging.info("Loading one label dataset...")
num_parallel_calls = config["data"]["task"]["num_parallel_calls"]
classes = config["data"]["task"]["classes"]
if isinstance(classes, list):
if output_index is None or output_index not in range(len(classes)):
raise IndexError(
"output_index:{} not in the range of classes length: "
"{}!".format(output_index, len(classes)))
num_classes = classes[output_index]["num_classes"]
label_vocab_file_path = config["data"]["task"]["label_vocab"][
output_index]
else:
num_classes = classes["num_classes"]
label_vocab_file_path = config["data"]["task"]["label_vocab"]
label_ds = label_ds.map(lambda x: tokenize_label(
x, maxlen=1, label_vocab_file_path=label_vocab_file_path, pad_id=0),
num_parallel_calls=num_parallel_calls)
label_ds = label_ds.map(
lambda l: tf.one_hot(l, num_classes, dtype=tf.int32),
num_parallel_calls=num_parallel_calls)
label_ds = label_ds.map(tf.squeeze, num_parallel_calls=num_parallel_calls)
return label_ds
def cross_entropy(logits,
labels,
input_length=None,
label_length=None,
smoothing=0.0,
reduction=tf.losses.Reduction.SUM_BY_NONZERO_WEIGHTS):
'''
cross entropy function for classfication and seq classfication
:param, label_length, for seq task, this for target seq length, e.g. a b c </s>, 4
'''
del input_length
onehot_labels = tf.cond(pred=tf.equal(
tf.rank(logits) - tf.rank(labels), 1),
true_fn=lambda: tf.one_hot(
labels, tf.shape(logits)[-1], dtype=tf.int32),
false_fn=lambda: labels)
if label_length is not None:
weights = utils.len_to_mask(label_length)
else:
weights = 1.0
loss = tf.losses.softmax_cross_entropy(onehot_labels=onehot_labels,
logits=logits,
weights=weights,
label_smoothing=smoothing,
reduction=reduction)
return loss
def test_dataset(self):
''' dataset unittest'''
batch_size = 4
self.config['solver']['optimizer']['batch_size'] = batch_size
task_name = self.config['data']['task']['name']
task_class = registers.task[task_name]
task = task_class(self.config, utils.TRAIN)
dataset = task.input_fn(utils.TRAIN, batch_size, 1)()
features, labels = dataset.make_one_shot_iterator().get_next()
samples = features['inputs']
filenames = features['filepath']
clip_ids = features['clipid']
soft_labels = features['soft_labels']
with self.cached_session(use_gpu=False, force_gpu=False) as sess:
while True:
batch_inputs, batch_labels, batch_files, batch_clipids, labels_onehot, batch_soft_labels = \
sess.run([samples, labels, filenames, clip_ids, tf.one_hot(labels, 2), soft_labels])
del labels_onehot
logging.info("feat shape: {}".format(batch_inputs.shape))
logging.info("labels: {}".format(batch_labels))
logging.info("filename: {}".format(batch_files))
logging.info("clip id: {}".format(batch_clipids))
logging.info("soft_labels: {}".format(batch_soft_labels))
break
def focal_loss(logits, labels, alpha, gamma=2, name='focal_loss'):
"""
Focal loss for multi classification
:param logits: A float32 tensor of shape [batch_size num_class].
:param labels: A int32 tensor of shape [batch_size, num_class] or [batch_size].
:param alpha: A 1D float32 tensor for focal loss alpha hyper-parameter
:param gamma: A scalar for focal loss gamma hyper-parameter.
Returns: A tensor of the same shape as `lables`
"""
if len(labels.shape) == 1:
labels = tf.one_hot(labels, logits.shape[-1])
else:
labels = labels
labels = tf.to_float(labels)
y_pred = tf.nn.softmax(logits, dim=-1)
L = -labels * tf.log(y_pred)
L *= alpha * ((1 - y_pred)**gamma)
loss = tf.reduce_sum(L)
if tf.executing_eagerly():
tf.contrib.summary.scalar(name, loss)
else:
tf.summary.scalar(name, loss)
return loss
def arcface_loss(embedding,
labels,
out_num,
weights=None,
s=64.,
m=0.5,
limit_to_pi=True):
'''
https://github.com/auroua/InsightFace_TF/blob/master/losses/face_losses.py
:param embedding: the input embedding vectors
:param labels: the input labels, the shape should be eg: (batch_size, 1)
:param s: scalar value default is 64
:param out_num: output class num
:param weights: a tf.variable with shape (embedding.shape[-1], out_num)
or None to make a new one internally. default = None
:param m: the margin value, default is 0.5
:return: the final cacualted output, this output is send into the tf.nn.softmax directly
'''
cos_m = math.cos(m)
sin_m = math.sin(m)
mm = sin_m * m # issue 1
threshold = math.cos(math.pi - m)
with tf.variable_scope('arcface_loss'):
# inputs and weights norm
embedding_norm = tf.norm(embedding, axis=1, keep_dims=True)
embedding = tf.div(embedding, embedding_norm, name='norm_embedding')
if weights is None:
weights = tf.get_variable(
name='weights',
shape=[embedding.shape[-1].value, out_num],
initializer=tf.initializer.glorot_unifrom())
weights_norm = tf.norm(weights, axis=0, keep_dims=True)
weights = tf.div(weights, weights_norm, name='norm_weights')
# cos(theta+m)
cos_t = tf.matmul(embedding, weights, name='cos_t')
cos_t2 = tf.square(cos_t, name='cos_2')
sin_t2 = tf.subtract(1., cos_t2, name='sin_2')
sin_t = tf.sqrt(sin_t2, name='sin_t')
cos_mt = s * tf.subtract(tf.multiply(cos_t, cos_m),
tf.multiply(sin_t, sin_m),
name='cos_mt')
if limit_to_pi:
# this condition controls the theta+m should in range [0, pi]
# 0<=theta+m<=pi
# -m<=theta<=pi-m
cond_v = cos_t - threshold
cond = tf.cast(tf.nn.relu(cond_v, name='if_else'), dtype=tf.bool)
keep_val = s * (cos_t - mm)
cos_mt_temp = tf.where(cond, cos_mt, keep_val)
else:
cos_mt_temp = cos_mt
mask = tf.one_hot(labels, depth=out_num, name='one_hot_mask')
# mask = tf.squeeze(mask, 1)
inv_mask = tf.subtract(1., mask, name='inverse_mask')
s_cos_t = tf.multiply(s, cos_t, name='scalar_cos_t')
output = tf.add(tf.multiply(s_cos_t, inv_mask),
tf.multiply(cos_mt_temp, mask),
name='arcface_loss_output')
return output