keras/keras_core/layers/reshaping/cropping1d.py
Francois Chollet ab1ab00beb Fixes
2023-05-31 13:45:14 -07:00

83 lines
2.7 KiB
Python

from keras_core.api_export import keras_core_export
from keras_core.layers.input_spec import InputSpec
from keras_core.layers.layer import Layer
from keras_core.utils import argument_validation
@keras_core_export("keras_core.layers.Cropping1D")
class Cropping1D(Layer):
"""Cropping layer for 1D input (e.g. temporal sequence).
It crops along the time dimension (axis 1).
Examples:
>>> input_shape = (2, 3, 2)
>>> x = np.arange(np.prod(input_shape)).reshape(input_shape)
>>> x
[[[ 0 1]
[ 2 3]
[ 4 5]]
[[ 6 7]
[ 8 9]
[10 11]]]
>>> y = keras_core.layers.Cropping1D(cropping=1)(x)
>>> y
[[[2 3]]
[[8 9]]]
Args:
cropping: Int, or tuple of int (length 2), or dictionary.
- If int: how many units should be trimmed off at the beginning and
end of the cropping dimension (axis 1).
- If tuple of 2 ints: how many units should be trimmed off at the
beginning and end of the cropping dimension
(`(left_crop, right_crop)`).
Input shape:
3D tensor with shape `(batch_size, axis_to_crop, features)`
Output shape:
3D tensor with shape `(batch_size, cropped_axis, features)`
"""
def __init__(self, cropping=(1, 1), **kwargs):
super().__init__(**kwargs)
self.cropping = argument_validation.standardize_tuple(
cropping, 2, "cropping", allow_zero=True
)
self.input_spec = InputSpec(ndim=3)
def compute_output_shape(self, input_shape):
if input_shape[1] is not None:
length = input_shape[1] - self.cropping[0] - self.cropping[1]
if length <= 0:
raise ValueError(
"`cropping` parameter of `Cropping1D` layer must be "
"greater than the input length. Received: input_shape="
f"{input_shape}, cropping={self.cropping}"
)
else:
length = None
return (input_shape[0], length, input_shape[2])
def call(self, inputs):
if (
inputs.shape[1] is not None
and sum(self.cropping) >= inputs.shape[1]
):
raise ValueError(
"`cropping` parameter of `Cropping1D` layer must be "
"greater than the input length. Received: inputs.shape="
f"{inputs.shape}, cropping={self.cropping}"
)
if self.cropping[1] == 0:
return inputs[:, self.cropping[0] :, :]
else:
return inputs[:, self.cropping[0] : -self.cropping[1], :]
def get_config(self):
config = {"cropping": self.cropping}
base_config = super().get_config()
return {**base_config, **config}