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paddlepaddle--paddle/python/paddle/vision/models/mobilenetv1.py
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2026-07-13 12:40:42 +08:00

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# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import annotations
from typing import (
TYPE_CHECKING,
TypedDict,
)
from typing_extensions import NotRequired, Unpack
import paddle
from paddle import nn
from paddle.utils.download import get_weights_path_from_url
from ..ops import ConvNormActivation
if TYPE_CHECKING:
from paddle import Tensor
from paddle._typing import Size2
class _MobileNetV1Options(TypedDict):
num_classes: NotRequired[int]
with_pool: NotRequired[bool]
__all__ = []
model_urls = {
'mobilenetv1_1.0': (
'https://paddle-hapi.bj.bcebos.com/models/mobilenetv1_1.0.pdparams',
'3033ab1975b1670bef51545feb65fc45',
)
}
class DepthwiseSeparable(nn.Layer):
def __init__(
self,
in_channels: int,
out_channels1: int,
out_channels2: int,
num_groups: int,
stride: Size2,
scale: float,
) -> None:
super().__init__()
self._depthwise_conv = ConvNormActivation(
in_channels,
int(out_channels1 * scale),
kernel_size=3,
stride=stride,
padding=1,
groups=int(num_groups * scale),
)
self._pointwise_conv = ConvNormActivation(
int(out_channels1 * scale),
int(out_channels2 * scale),
kernel_size=1,
stride=1,
padding=0,
)
def forward(self, x: Tensor) -> Tensor:
x = self._depthwise_conv(x)
x = self._pointwise_conv(x)
return x
class MobileNetV1(nn.Layer):
"""MobileNetV1 model from
`"MobileNets: Efficient Convolutional Neural Networks for Mobile Vision Applications" <https://arxiv.org/abs/1704.04861>`_.
Args:
scale (float, optional): Scale of channels in each layer. Default: 1.0.
num_classes (int, optional): Output dim of last fc layer. If num_classes <= 0, last fc layer
will not be defined. Default: 1000.
with_pool (bool, optional): Use pool before the last fc layer or not. Default: True.
Returns:
:ref:`api_paddle_nn_Layer`. An instance of MobileNetV1 model.
Examples:
.. code-block:: pycon
>>> import paddle
>>> from paddle.vision.models import MobileNetV1
>>> model = MobileNetV1()
>>> x = paddle.rand([1, 3, 224, 224])
>>> out = model(x)
>>> print(out.shape)
paddle.Size([1, 1000])
"""
scale: float
num_classes: int
with_pool: bool
def __init__(
self,
scale: float = 1.0,
num_classes: int = 1000,
with_pool: bool = True,
) -> None:
super().__init__()
self.scale = scale
self.dwsl = []
self.num_classes = num_classes
self.with_pool = with_pool
self.conv1 = ConvNormActivation(
in_channels=3,
out_channels=int(32 * scale),
kernel_size=3,
stride=2,
padding=1,
)
dws21 = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(32 * scale),
out_channels1=32,
out_channels2=64,
num_groups=32,
stride=1,
scale=scale,
),
name="conv2_1",
)
self.dwsl.append(dws21)
dws22 = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(64 * scale),
out_channels1=64,
out_channels2=128,
num_groups=64,
stride=2,
scale=scale,
),
name="conv2_2",
)
self.dwsl.append(dws22)
dws31 = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(128 * scale),
out_channels1=128,
out_channels2=128,
num_groups=128,
stride=1,
scale=scale,
),
name="conv3_1",
)
self.dwsl.append(dws31)
dws32 = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(128 * scale),
out_channels1=128,
out_channels2=256,
num_groups=128,
stride=2,
scale=scale,
),
name="conv3_2",
)
self.dwsl.append(dws32)
dws41 = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(256 * scale),
out_channels1=256,
out_channels2=256,
num_groups=256,
stride=1,
scale=scale,
),
name="conv4_1",
)
self.dwsl.append(dws41)
dws42 = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(256 * scale),
out_channels1=256,
out_channels2=512,
num_groups=256,
stride=2,
scale=scale,
),
name="conv4_2",
)
self.dwsl.append(dws42)
for i in range(5):
tmp = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(512 * scale),
out_channels1=512,
out_channels2=512,
num_groups=512,
stride=1,
scale=scale,
),
name="conv5_" + str(i + 1),
)
self.dwsl.append(tmp)
dws56 = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(512 * scale),
out_channels1=512,
out_channels2=1024,
num_groups=512,
stride=2,
scale=scale,
),
name="conv5_6",
)
self.dwsl.append(dws56)
dws6 = self.add_sublayer(
sublayer=DepthwiseSeparable(
in_channels=int(1024 * scale),
out_channels1=1024,
out_channels2=1024,
num_groups=1024,
stride=1,
scale=scale,
),
name="conv6",
)
self.dwsl.append(dws6)
if with_pool:
self.pool2d_avg = nn.AdaptiveAvgPool2D(1)
if num_classes > 0:
self.fc = nn.Linear(int(1024 * scale), num_classes)
def forward(self, x: Tensor) -> Tensor:
x = self.conv1(x)
for dws in self.dwsl:
x = dws(x)
if self.with_pool:
x = self.pool2d_avg(x)
if self.num_classes > 0:
x = paddle.flatten(x, 1)
x = self.fc(x)
return x
def _mobilenet(
arch: str, pretrained: bool = False, **kwargs: Unpack[_MobileNetV1Options]
) -> MobileNetV1:
model = MobileNetV1(**kwargs)
if pretrained:
assert arch in model_urls, (
f"{arch} model do not have a pretrained model now, you should set pretrained=False"
)
weight_path = get_weights_path_from_url(
model_urls[arch][0], model_urls[arch][1]
)
param = paddle.load(weight_path)
model.load_dict(param)
return model
def mobilenet_v1(
pretrained: bool = False,
scale: float = 1.0,
**kwargs: Unpack[_MobileNetV1Options],
) -> MobileNetV1:
"""MobileNetV1 from
`"MobileNets: Efficient Convolutional Neural Networks for Mobile Vision Applications" <https://arxiv.org/abs/1704.04861>`_.
Args:
pretrained (bool, optional): Whether to load pre-trained weights. If True, returns a model pre-trained
on ImageNet. Default: False.
scale (float, optional): Scale of channels in each layer. Default: 1.0.
**kwargs (optional): Additional keyword arguments. For details, please refer to :ref:`MobileNetV1 <api_paddle_vision_models_MobileNetV1>`.
Returns:
:ref:`api_paddle_nn_Layer`. An instance of MobileNetV1 model.
Examples:
.. code-block:: pycon
>>> import paddle
>>> from paddle.vision.models import mobilenet_v1
>>> # Build model
>>> model = mobilenet_v1()
>>> # Build model and load imagenet pretrained weight
>>> # model = mobilenet_v1(pretrained=True)
>>> # build mobilenet v1 with scale=0.5
>>> model_scale = mobilenet_v1(scale=0.5)
>>> x = paddle.rand([1, 3, 224, 224])
>>> out = model(x)
>>> print(out.shape)
paddle.Size([1, 1000])
"""
model = _mobilenet(
'mobilenetv1_' + str(scale), pretrained, scale=scale, **kwargs
)
return model