keras/keras_core/layers/reshaping/cropping2d.py
2023-05-11 15:58:31 -07:00

213 lines
8.5 KiB
Python

from keras_core import backend
from keras_core.api_export import keras_core_export
from keras_core.layers.input_spec import InputSpec
from keras_core.layers.layer import Layer
@keras_core_export("keras_core.layers.Cropping2D")
class Cropping2D(Layer):
"""Cropping layer for 2D input (e.g. picture).
It crops along spatial dimensions, i.e. height and width.
Examples:
>>> input_shape = (2, 28, 28, 3)
>>> x = np.arange(np.prod(input_shape)).reshape(input_shape)
>>> y = keras_core.layers.Cropping2D(cropping=((2, 2), (4, 4)))(x)
>>> y.shape
(2, 24, 20, 3)
Args:
cropping: Int, or tuple of 2 ints, or tuple of 2 tuples of 2 ints.
- If int: the same symmetric cropping is applied to height and
width.
- If tuple of 2 ints: interpreted as two different symmetric
cropping values for height and width:
`(symmetric_height_crop, symmetric_width_crop)`.
- If tuple of 2 tuples of 2 ints: interpreted as
`((top_crop, bottom_crop), (left_crop, right_crop))`
data_format: A string, one of `"channels_last"` (default) or
`"channels_first"`. The ordering of the dimensions in the inputs.
`"channels_last"` corresponds to inputs with shape
`(batch_size, height, width, channels)` while `"channels_first"`
corresponds to inputs with shape
`(batch_size, channels, height, width)`.
When unspecified, uses `image_data_format` value found in your Keras
config file at `~/.keras/keras.json` (if exists). Defaults to
`"channels_last"`.
Input shape:
4D tensor with shape:
- If `data_format` is `"channels_last"`:
`(batch_size, height, width, channels)`
- If `data_format` is `"channels_first"`:
`(batch_size, channels, height, width)`
Output shape:
4D tensor with shape:
- If `data_format` is `"channels_last"`:
`(batch_size, cropped_height, cropped_width, channels)`
- If `data_format` is `"channels_first"`:
`(batch_size, channels, cropped_height, cropped_width)`
"""
def __init__(
self, cropping=((0, 0), (0, 0)), data_format=None, name=None, dtype=None
):
super().__init__(name=name, dtype=dtype)
self.data_format = backend.standardize_data_format(data_format)
if isinstance(cropping, int):
self.cropping = ((cropping, cropping), (cropping, cropping))
elif hasattr(cropping, "__len__"):
if len(cropping) != 2:
raise ValueError(
"`cropping` should have two elements. "
f"Received: cropping={cropping}."
)
height_cropping = cropping[0]
if isinstance(height_cropping, int):
height_cropping = (height_cropping, height_cropping)
width_cropping = cropping[1]
if isinstance(width_cropping, int):
width_cropping = (width_cropping, width_cropping)
self.cropping = (height_cropping, width_cropping)
else:
raise ValueError(
"`cropping` should be either an int, a tuple of 2 ints "
"(symmetric_height_crop, symmetric_width_crop), "
"or a tuple of 2 tuples of 2 ints "
"((top_crop, bottom_crop), (left_crop, right_crop)). "
f"Received: cropping={cropping}."
)
self.input_spec = InputSpec(ndim=4)
def compute_output_shape(self, input_shape):
if self.data_format == "channels_first":
if (
input_shape[2] is not None
and sum(self.cropping[0]) >= input_shape[2]
) or (
input_shape[3] is not None
and sum(self.cropping[1]) >= input_shape[3]
):
raise ValueError(
"Values in `cropping` argument should be greater than the "
"corresponding spatial dimension of the input. Received: "
f"input_shape={input_shape}, cropping={self.cropping}"
)
return (
input_shape[0],
input_shape[1],
input_shape[2] - self.cropping[0][0] - self.cropping[0][1]
if input_shape[2] is not None
else None,
input_shape[3] - self.cropping[1][0] - self.cropping[1][1]
if input_shape[3] is not None
else None,
)
else:
if (
input_shape[1] is not None
and sum(self.cropping[0]) >= input_shape[1]
) or (
input_shape[2] is not None
and sum(self.cropping[1]) >= input_shape[2]
):
raise ValueError(
"Values in `cropping` argument should be greater than the "
"corresponding spatial dimension of the input. Received: "
f"input_shape={input_shape}, cropping={self.cropping}"
)
return (
input_shape[0],
input_shape[1] - self.cropping[0][0] - self.cropping[0][1]
if input_shape[1] is not None
else None,
input_shape[2] - self.cropping[1][0] - self.cropping[1][1]
if input_shape[2] is not None
else None,
input_shape[3],
)
def call(self, inputs):
if self.data_format == "channels_first":
if (
inputs.shape[2] is not None
and sum(self.cropping[0]) >= inputs.shape[2]
) or (
inputs.shape[3] is not None
and sum(self.cropping[1]) >= inputs.shape[3]
):
raise ValueError(
"Values in `cropping` argument should be greater than the "
"corresponding spatial dimension of the input. Received: "
f"inputs.shape={inputs.shape}, cropping={self.cropping}"
)
if self.cropping[0][1] == self.cropping[1][1] == 0:
return inputs[
:, :, self.cropping[0][0] :, self.cropping[1][0] :
]
elif self.cropping[0][1] == 0:
return inputs[
:,
:,
self.cropping[0][0] :,
self.cropping[1][0] : -self.cropping[1][1],
]
elif self.cropping[1][1] == 0:
return inputs[
:,
:,
self.cropping[0][0] : -self.cropping[0][1],
self.cropping[1][0] :,
]
return inputs[
:,
:,
self.cropping[0][0] : -self.cropping[0][1],
self.cropping[1][0] : -self.cropping[1][1],
]
else:
if (
inputs.shape[1] is not None
and sum(self.cropping[0]) >= inputs.shape[1]
) or (
inputs.shape[2] is not None
and sum(self.cropping[1]) >= inputs.shape[2]
):
raise ValueError(
"Values in `cropping` argument should be greater than the "
"corresponding spatial dimension of the input. Received: "
f"inputs.shape={inputs.shape}, cropping={self.cropping}"
)
if self.cropping[0][1] == self.cropping[1][1] == 0:
return inputs[
:, self.cropping[0][0] :, self.cropping[1][0] :, :
]
elif self.cropping[0][1] == 0:
return inputs[
:,
self.cropping[0][0] :,
self.cropping[1][0] : -self.cropping[1][1],
:,
]
elif self.cropping[1][1] == 0:
return inputs[
:,
self.cropping[0][0] : -self.cropping[0][1],
self.cropping[1][0] :,
:,
]
return inputs[
:,
self.cropping[0][0] : -self.cropping[0][1],
self.cropping[1][0] : -self.cropping[1][1],
:,
]
def get_config(self):
config = {"cropping": self.cropping, "data_format": self.data_format}
base_config = super().get_config()
return {**base_config, **config}