def standardize_image(
image_bytes: tf.Tensor,
stddev: Tuple[float, ...],
num_channels: int = 3,
dtype: tf.dtypes.DType = tf.float32,
) -> tf.Tensor:
"""Divides the given stddev from each image channel.
For example:
stddev = [123.68, 116.779, 103.939]
image_bytes = standardize_image(image_bytes, stddev)
Note that the rank of `image` must be known.
Args:
image_bytes: a tensor of size [height, width, C].
stddev: a C-vector of values to divide from each channel.
num_channels: number of color channels in the image that will be distorted.
dtype: the dtype to convert the images to. Set to `None` to skip conversion.
Returns:
the centered image.
Raises:
ValueError: If the rank of `image` is unknown, if `image` has a rank other
than three or if the number of channels in `image` doesn't match the
number of values in `stddev`.
"""
if image_bytes.get_shape().ndims != 3:
raise ValueError('Input must be of size [height, width, C>0]')
if len(stddev) != num_channels:
raise ValueError('len(stddev) must match the number of channels')
# We have a 1-D tensor of stddev; convert to 3-D.
# Note(b/130245863): we explicitly call `broadcast` instead of simply
# expanding dimensions for better performance.
stddev = tf.broadcast_to(stddev, tf.shape(image_bytes))
if dtype is not None:
stddev = tf.cast(stddev, dtype=dtype)
return image_bytes / stddev
def call(self, inputs: tf.Tensor) -> Tuple[tf.Tensor, tf.Tensor]:
"""Forward pass of the model.
Takes as input a sound processed by CARFAC, FFT, and a power calculation
resulting in a tensor of shape [bsz, CARFAC channels, frequency bins, 2]
where 2 is signal power and noise power in dB.
Args:
inputs: a batch of inputs [bsz, CARFAC channels, frequency bins, 2]
Returns:
A tuple of tensors containing the loundess predictions in phons per
frequency bin and a soft mask over these bins.
"""
(_, channels, bins, feature_dim) = inputs.get_shape().as_list()
if not self.use_channels:
# [bsz, 1, bins, dim] -> [bsz, 1, bins * dim]
# [bsz, 1, bins, 1] -> [bsz, bins, 1]
inputs = tf.squeeze(inputs, axis=1)
# [bsz, bins, 1] -> [bsz, hidden_dim]
hidden = self.bilstm(inputs)
hidden = self.dropout(hidden)
# [bsz, hidden_dim] -> [bsz, 1]
output = self.relu(self.hidden_to_logits(hidden))
# [bsz, 1] -> [bsz]
output = tf.squeeze(output, axis=1)
else:
# [bsz, channels, bins, dim] -> [bsz, bins, channels, dim]
inputs = tf.transpose(inputs, perm=[0, 2, 1, 3])
# [bsz, bins, 1, dim]
conditioning = inputs[:, :, -1, :]
# [bsz, bins, 1, dim]
coefs = inputs[:, :, -2, :]
# [bsz, bins + 1]
coefs = tf.concat(
[coefs, tf.expand_dims(conditioning[:, 0], axis=2)], axis=1)
# [bsz, bins + 1, 1] -> [bsz, hidden_dim]
hidden_two = self.bilstm_two(coefs)
# [bsz, bins, carfac_channels, dim]
inputs = inputs[:, :, :-2, :]
inputs = self.dropout(inputs)
# [bsz, bins, carfac_shannels, dim] -> [bsz, bins, carfac_channels * dim]
inputs = tf.reshape(inputs,
[-1, bins, (channels - 2) * feature_dim])
# [bsz, bins, carfac_channels * dim] -> [bsz, bins, hidden_dim]
hidden = self.features_to_hidden(inputs)
# [bsz, bins, hidden_dim] -> [bsz, hidden_dim]
hidden_one = self.bilstm_one(hidden)
hidden = self.dropout(hidden)
# (_, bins, feature_dim) = hidden.get_shape().as_list()
# # [bsz, bins, hidden_dim] -> [bsz, bins * hidden_dim]
# hidden_flat = tf.reshape(hidden, [-1, bins * feature_dim])
# [bsz, hidden_dim] -> [bsz, hidden_dim + hidden_dim]
hidden = tf.concat([hidden_one, hidden_two], axis=1)
# [bsz, hidden_dim + hidden_dim] -> [bsz, 1]
output = self.relu(self.hidden_to_logits(hidden))
if len(output.get_shape().as_list()) == 1:
output = tf.expand_dims(output, axis=0)
return output
def _check_value(self, tensor: tf.Tensor, tensorspec: tf.TensorSpec):
if not tf.TensorShape(tf.squeeze(
tensor.get_shape())).is_compatible_with(tensorspec.shape):
raise ValueError(
'Tensor {} is not compatible with specification {}.'.format(
tensor, tensorspec))
def stateless_dropout(x: tf.Tensor,
rate: float,
seed: tf.Tensor,
noise_shape: Optional[Union[Sequence[int],
tf.TensorShape]] = None,
name: Optional[Text] = None) -> tf.Tensor:
"""Computes dropout: randomly sets elements to zero to prevent overfitting.
See https://www.tensorflow.org/api_docs/python/tf/nn/dropout.
This version differs in that the seed is required if the rate is nonzero.
Args:
x: A floating point tensor.
rate: A scalar `Tensor` with the same type as x. The probability that each
element is dropped. For example, setting rate=0.1 would drop 10% of input
elements.
seed: A shape [2] integer Tensor of seeds to the random number generator.
Must have dtype `tf.int32` when compiling to XLA.
noise_shape: A 1-D `Tensor` of type `int32`, representing the shape for
randomly generated keep/drop flags.
name: A name for this operation (optional).
Returns:
A `Tensor` of the same shape of `x`.
Raises:
ValueError: If `rate` is not in `[0, 1)` or if `x` is not a floating point
tensor. `rate=1` is disallowed, because the output would be all zeros,
which is likely not what was intended.
"""
with tf.name_scope(name or 'stateless_dropout') as name:
x = tf.convert_to_tensor(x, name='x')
if not x.dtype.is_floating:
raise ValueError(
'x has to be a floating point tensor since it\'s going '
' to be scaled. Got a %s tensor instead.' % x.dtype)
if isinstance(rate, numbers.Real):
if not (rate >= 0 and rate < 1):
raise ValueError(
'rate must be a scalar tensor or a float in the '
'range [0, 1), got %g' % rate)
if rate > 0.5:
logging.log_first_n(
logging.WARN,
'Large dropout rate: %g (>0.5). In TensorFlow '
'.x, dropout() uses dropout rate instead of keep_prob. '
'Please ensure that this is intended.', 5, rate)
# Early return if nothing needs to be dropped.
if tf.get_static_value(rate) == 0:
return x
rate = tf.convert_to_tensor(rate, dtype=x.dtype, name='rate')
rate.shape.assert_has_rank(0)
noise_shape = _get_noise_shape(x, noise_shape)
# Sample a uniform distribution on [0.0, 1.0) and select values larger than
# rate.
#
# NOTE: Random uniform actually can only generate 2^23 floats on [1.0, 2.0)
# and subtract 1.0.
random_tensor = tf.random.stateless_uniform(noise_shape,
seed=seed,
dtype=x.dtype)
keep_prob = 1 - rate
scale = 1 / keep_prob
# NOTE: if (1.0 + rate) - 1 is equal to rate, then we want to consider that
# float to be selected, hence we use a >= comparison.
keep_mask = random_tensor >= rate
ret = x * scale * tf.cast(keep_mask, x.dtype)
if not tf.executing_eagerly():
ret.set_shape(x.get_shape())
return ret