def testIgnorePositiveExampleLossViaAlphaMultiplier(self):
prediction_tensor = tf.constant(
[[[_logit(0.55)], [_logit(0.52)], [_logit(0.50)], [_logit(0.48)],
[_logit(0.45)]]], tf.float32)
target_tensor = tf.constant([[[1], [1], [1], [0], [0]]], tf.float32)
weights = tf.constant([[1, 1, 1, 1, 1]], tf.float32)
focal_loss_op = losses.SigmoidFocalClassificationLoss(gamma=2.0,
alpha=0.0)
sigmoid_loss_op = losses.WeightedSigmoidClassificationLoss()
focal_loss = tf.reduce_sum(focal_loss_op(prediction_tensor,
target_tensor,
weights=weights),
axis=2)
sigmoid_loss = tf.reduce_sum(sigmoid_loss_op(prediction_tensor,
target_tensor,
weights=weights),
axis=2)
with self.test_session() as sess:
sigmoid_loss, focal_loss = sess.run([sigmoid_loss, focal_loss])
self.assertAllClose(focal_loss[0][:3], [0., 0., 0.])
order_of_ratio = np.power(
10,
np.floor(np.log10(sigmoid_loss[0][3:] / focal_loss[0][3:])))
self.assertAllClose(order_of_ratio, [1., 1.])
def testEasyExamplesProduceSmallLossComparedToSigmoidXEntropy(self):
prediction_tensor = tf.constant(
[[[_logit(0.97)], [_logit(0.91)], [_logit(0.73)], [_logit(0.27)],
[_logit(0.09)], [_logit(0.03)]]], tf.float32)
target_tensor = tf.constant([[[1], [1], [1], [0], [0], [0]]],
tf.float32)
weights = tf.constant([[1, 1, 1, 1, 1, 1]], tf.float32)
focal_loss_op = losses.SigmoidFocalClassificationLoss(gamma=2.0,
alpha=None)
sigmoid_loss_op = losses.WeightedSigmoidClassificationLoss()
focal_loss = tf.reduce_sum(focal_loss_op(prediction_tensor,
target_tensor,
weights=weights),
axis=2)
sigmoid_loss = tf.reduce_sum(sigmoid_loss_op(prediction_tensor,
target_tensor,
weights=weights),
axis=2)
with self.test_session() as sess:
sigmoid_loss, focal_loss = sess.run([sigmoid_loss, focal_loss])
order_of_ratio = np.power(
10, np.floor(np.log10(sigmoid_loss / focal_loss)))
self.assertAllClose(order_of_ratio,
[[1000, 100, 10, 10, 100, 1000]])
def testReturnsCorrectLossWithClassIndices(self):
prediction_tensor = tf.constant(
[[[-100, 100, -100, 100], [100, -100, -100, -100],
[100, 0, -100, 100], [-100, -100, 100, -100]],
[[-100, 0, 100, 100], [-100, 100, -100, 100],
[100, 100, 100, 100], [0, 0, -1, 100]]], tf.float32)
target_tensor = tf.constant(
[[[0, 1, 0, 0], [1, 0, 0, 1], [1, 0, 0, 0], [0, 0, 1, 1]],
[[0, 0, 1, 0], [0, 1, 0, 0], [1, 1, 1, 0], [1, 0, 0, 0]]],
tf.float32)
weights = tf.constant([[1, 1, 1, 1], [1, 1, 1, 0]], tf.float32)
# Ignores the last class.
class_indices = tf.constant([0, 1, 2], tf.int32)
loss_op = losses.WeightedSigmoidClassificationLoss()
loss = loss_op(prediction_tensor,
target_tensor,
weights=weights,
class_indices=class_indices)
loss = tf.reduce_sum(loss, axis=2)
exp_loss = np.matrix([[0, 0, -math.log(.5), 0],
[-math.log(.5), 0, 0, 0]])
with self.test_session() as sess:
loss_output = sess.run(loss)
self.assertAllClose(loss_output, exp_loss)
def build_faster_rcnn_classification_loss(loss_config):
"""Builds a classification loss for Faster RCNN based on the loss config.
Args:
loss_config: A losses_pb2.ClassificationLoss object.
Returns:
Loss based on the config.
Raises:
ValueError: On invalid loss_config.
"""
if not isinstance(loss_config, losses_pb2.ClassificationLoss):
raise ValueError(
'loss_config not of type losses_pb2.ClassificationLoss.')
loss_type = loss_config.WhichOneof('classification_loss')
if loss_type == 'weighted_sigmoid':
return losses.WeightedSigmoidClassificationLoss()
if loss_type == 'weighted_softmax':
config = loss_config.weighted_softmax
return losses.WeightedSoftmaxClassificationLoss(
logit_scale=config.logit_scale)
if loss_type == 'weighted_logits_softmax':
config = loss_config.weighted_logits_softmax
return losses.WeightedSoftmaxClassificationAgainstLogitsLoss(
logit_scale=config.logit_scale)
# By default, Faster RCNN second stage classifier uses Softmax loss
# with anchor-wise outputs.
config = loss_config.weighted_softmax
return losses.WeightedSoftmaxClassificationLoss(
logit_scale=config.logit_scale)
def _build_classification_loss(loss_config):
"""Builds a classification loss based on the loss config.
Args:
loss_config: A losses_pb2.ClassificationLoss object.
Returns:
Loss based on the config.
Raises:
ValueError: On invalid loss_config.
"""
if not isinstance(loss_config, losses_pb2.ClassificationLoss):
raise ValueError(
'loss_config not of type losses_pb2.ClassificationLoss.')
loss_type = loss_config.WhichOneof('classification_loss')
if loss_type == 'weighted_sigmoid':
return losses.WeightedSigmoidClassificationLoss()
if loss_type == 'weighted_sigmoid_focal':
config = loss_config.weighted_sigmoid_focal
alpha = None
if config.HasField('alpha'):
alpha = config.alpha
return losses.SigmoidFocalClassificationLoss(gamma=config.gamma,
alpha=alpha)
if loss_type == 'weighted_softmax':
config = loss_config.weighted_softmax
return losses.WeightedSoftmaxClassificationLoss(
logit_scale=config.logit_scale)
if loss_type == 'weighted_logits_softmax':
config = loss_config.weighted_logits_softmax
return losses.WeightedSoftmaxClassificationAgainstLogitsLoss(
logit_scale=config.logit_scale)
if loss_type == 'bootstrapped_sigmoid':
config = loss_config.bootstrapped_sigmoid
return losses.BootstrappedSigmoidClassificationLoss(
alpha=config.alpha,
bootstrap_type=('hard' if config.hard_bootstrap else 'soft'))
raise ValueError('Empty loss config.')
def testReturnsCorrectLoss(self):
prediction_tensor = tf.constant(
[[[-100, 100, -100], [100, -100, -100], [100, 0, -100],
[-100, -100, 100]],
[[-100, 0, 100], [-100, 100, -100], [100, 100, 100], [0, 0, -1]]],
tf.float32)
target_tensor = tf.constant(
[[[0, 1, 0], [1, 0, 0], [1, 0, 0], [0, 0, 1]],
[[0, 0, 1], [0, 1, 0], [1, 1, 1], [1, 0, 0]]], tf.float32)
weights = tf.constant([[1, 1, 1, 1], [1, 1, 1, 0]], tf.float32)
loss_op = losses.WeightedSigmoidClassificationLoss()
loss = loss_op(prediction_tensor, target_tensor, weights=weights)
loss = tf.reduce_sum(loss)
exp_loss = -2 * math.log(.5)
with self.test_session() as sess:
loss_output = sess.run(loss)
self.assertAllClose(loss_output, exp_loss)
def testNonAnchorWiseOutputComparableToSigmoidXEntropy(self):
prediction_tensor = tf.constant(
[[[_logit(0.55)], [_logit(0.52)], [_logit(0.50)], [_logit(0.48)],
[_logit(0.45)]]], tf.float32)
target_tensor = tf.constant([[[1], [1], [1], [0], [0]]], tf.float32)
weights = tf.constant([[1, 1, 1, 1, 1]], tf.float32)
focal_loss_op = losses.SigmoidFocalClassificationLoss(gamma=2.0,
alpha=None)
sigmoid_loss_op = losses.WeightedSigmoidClassificationLoss()
focal_loss = tf.reduce_sum(
focal_loss_op(prediction_tensor, target_tensor, weights=weights))
sigmoid_loss = tf.reduce_sum(
sigmoid_loss_op(prediction_tensor, target_tensor, weights=weights))
with self.test_session() as sess:
sigmoid_loss, focal_loss = sess.run([sigmoid_loss, focal_loss])
order_of_ratio = np.power(
10, np.floor(np.log10(sigmoid_loss / focal_loss)))
self.assertAlmostEqual(order_of_ratio, 1.)
def testSameAsSigmoidXEntropyWithNoAlphaAndZeroGamma(self):
prediction_tensor = tf.constant(
[[[-100, 100, -100], [100, -100, -100], [100, 0, -100],
[-100, -100, 100]],
[[-100, 0, 100], [-100, 100, -100], [100, 100, 100], [0, 0, -1]]],
tf.float32)
target_tensor = tf.constant(
[[[0, 1, 0], [1, 0, 0], [1, 0, 0], [0, 0, 1]],
[[0, 0, 1], [0, 1, 0], [1, 1, 1], [1, 0, 0]]], tf.float32)
weights = tf.constant([[1, 1, 1, 1], [1, 1, 1, 0]], tf.float32)
focal_loss_op = losses.SigmoidFocalClassificationLoss(alpha=None,
gamma=0.0)
sigmoid_loss_op = losses.WeightedSigmoidClassificationLoss()
focal_loss = focal_loss_op(prediction_tensor,
target_tensor,
weights=weights)
sigmoid_loss = sigmoid_loss_op(prediction_tensor,
target_tensor,
weights=weights)
with self.test_session() as sess:
sigmoid_loss, focal_loss = sess.run([sigmoid_loss, focal_loss])
self.assertAllClose(sigmoid_loss, focal_loss)
def _create_model(self,
apply_hard_mining=True,
normalize_loc_loss_by_codesize=False,
add_background_class=True,
random_example_sampling=False,
use_keras=False):
is_training = False
num_classes = 1
mock_anchor_generator = MockAnchorGenerator2x2()
if use_keras:
mock_box_predictor = test_utils.MockKerasBoxPredictor(
is_training, num_classes)
else:
mock_box_predictor = test_utils.MockBoxPredictor(
is_training, num_classes)
mock_box_coder = test_utils.MockBoxCoder()
if use_keras:
fake_feature_extractor = FakeSSDKerasFeatureExtractor()
else:
fake_feature_extractor = FakeSSDFeatureExtractor()
mock_matcher = test_utils.MockMatcher()
region_similarity_calculator = sim_calc.IouSimilarity()
encode_background_as_zeros = False
def image_resizer_fn(image):
return [tf.identity(image), tf.shape(image)]
classification_loss = losses.WeightedSigmoidClassificationLoss()
localization_loss = losses.WeightedSmoothL1LocalizationLoss()
non_max_suppression_fn = functools.partial(
post_processing.batch_multiclass_non_max_suppression,
score_thresh=-20.0,
iou_thresh=1.0,
max_size_per_class=5,
max_total_size=5)
classification_loss_weight = 1.0
localization_loss_weight = 1.0
negative_class_weight = 1.0
normalize_loss_by_num_matches = False
hard_example_miner = None
if apply_hard_mining:
# This hard example miner is expected to be a no-op.
hard_example_miner = losses.HardExampleMiner(
num_hard_examples=None,
iou_threshold=1.0)
random_example_sampler = None
if random_example_sampling:
random_example_sampler = sampler.BalancedPositiveNegativeSampler(
positive_fraction=0.5)
code_size = 4
model = ssd_meta_arch.SSDMetaArch(
is_training,
mock_anchor_generator,
mock_box_predictor,
mock_box_coder,
fake_feature_extractor,
mock_matcher,
region_similarity_calculator,
encode_background_as_zeros,
negative_class_weight,
image_resizer_fn,
non_max_suppression_fn,
tf.identity,
classification_loss,
localization_loss,
classification_loss_weight,
localization_loss_weight,
normalize_loss_by_num_matches,
hard_example_miner,
add_summaries=False,
normalize_loc_loss_by_codesize=normalize_loc_loss_by_codesize,
freeze_batchnorm=False,
inplace_batchnorm_update=False,
add_background_class=add_background_class,
random_example_sampler=random_example_sampler)
return model, num_classes, mock_anchor_generator.num_anchors(), code_size
def __init__(self):
super(FakeDetectionModel, self).__init__(num_classes=NUMBER_OF_CLASSES)
self._classification_loss = losses.WeightedSigmoidClassificationLoss()
self._localization_loss = losses.WeightedSmoothL1LocalizationLoss()