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(
anchorwise_output=True, gamma=2.0, alpha=0.0)
sigmoid_loss_op = losses.WeightedSigmoidClassificationLoss(
anchorwise_output=True)
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(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 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(
anchorwise_output=True, alpha=None, gamma=0.0)
sigmoid_loss_op = losses.WeightedSigmoidClassificationLoss(
anchorwise_output=True)
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 testEasyExamplesProduceSmallLossComparedToSigmoidXEntropy(self):
prediction_tensor = tf.constant([[[_logit(0.97)],
[_logit(0.90)],
[_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(
anchorwise_output=True, gamma=2.0, alpha=None)
sigmoid_loss_op = losses.WeightedSigmoidClassificationLoss(
anchorwise_output=True)
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])
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 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(
anchorwise_output=False, gamma=2.0, alpha=None)
sigmoid_loss_op = losses.WeightedSigmoidClassificationLoss(
anchorwise_output=False)
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])
order_of_ratio = np.power(10,
np.floor(np.log10(sigmoid_loss / focal_loss)))
self.assertAlmostEqual(order_of_ratio, 1.)
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(True)
loss = loss_op(prediction_tensor, target_tensor, weights=weights,
class_indices=class_indices)
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 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)
exp_loss = -2 * math.log(.5)
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':
config = loss_config.weighted_sigmoid
return losses.WeightedSigmoidClassificationLoss(
anchorwise_output=config.anchorwise_output)
if loss_type == 'weighted_softmax':
config = loss_config.weighted_softmax
return losses.WeightedSoftmaxClassificationLoss(
anchorwise_output=config.anchorwise_output)
# By default, Faster RCNN second stage classifier uses Softmax loss
# with anchor-wise outputs.
return losses.WeightedSoftmaxClassificationLoss(anchorwise_output=True)
def setUp(self):
"""Set up mock SSD model.
Here we set up a simple mock SSD model that will always predict 4
detections that happen to always be exactly the anchors that are set up
in the above MockAnchorGenerator. Because we let max_detections=5,
we will also always end up with an extra padded row in the detection
results.
"""
is_training = False
self._num_classes = 1
mock_anchor_generator = MockAnchorGenerator2x2()
mock_box_predictor = test_utils.MockBoxPredictor(
is_training, self._num_classes)
mock_box_coder = test_utils.MockBoxCoder()
fake_feature_extractor = FakeSSDFeatureExtractor()
mock_matcher = test_utils.MockMatcher()
region_similarity_calculator = sim_calc.IouSimilarity()
def image_resizer_fn(image):
return tf.identity(image)
classification_loss = losses.WeightedSigmoidClassificationLoss(
anchorwise_output=True)
localization_loss = losses.WeightedSmoothL1LocalizationLoss(
anchorwise_output=True)
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
normalize_loss_by_num_matches = False
# This hard example miner is expected to be a no-op.
hard_example_miner = losses.HardExampleMiner(num_hard_examples=None,
iou_threshold=1.0)
self._num_anchors = 4
self._code_size = 4
self._model = ssd_meta_arch.SSDMetaArch(
is_training, mock_anchor_generator, mock_box_predictor,
mock_box_coder, fake_feature_extractor, mock_matcher,
region_similarity_calculator, 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)
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':
config = loss_config.weighted_sigmoid
return losses.WeightedSigmoidClassificationLoss(
anchorwise_output=config.anchorwise_output)
if loss_type == 'weighted_sigmoid_focal':
config = loss_config.weighted_sigmoid_focal
alpha = None
if config.HasField('alpha'):
alpha = config.alpha
return losses.SigmoidFocalClassificationLoss(
anchorwise_output=config.anchorwise_output,
gamma=config.gamma,
alpha=alpha)
if loss_type == 'weighted_softmax':
config = loss_config.weighted_softmax
return losses.WeightedSoftmaxClassificationLoss(
anchorwise_output=config.anchorwise_output,
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'),
anchorwise_output=config.anchorwise_output)
raise ValueError('Empty loss config.')
def __init__(self):
super(FakeDetectionModel, self).__init__(num_classes=NUMBER_OF_CLASSES)
self._classification_loss = losses.WeightedSigmoidClassificationLoss(
anchorwise_output=True)
self._localization_loss = losses.WeightedSmoothL1LocalizationLoss(
anchorwise_output=True)