PulseFocusPlatform/static/ppdet/modeling/backbones/resnext.py

90 lines
3.3 KiB
Python

# Copyright (c) 2019 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 absolute_import
from __future__ import division
from __future__ import print_function
from ppdet.core.workspace import register, serializable
from .resnet import ResNet
__all__ = ['ResNeXt']
@register
@serializable
class ResNeXt(ResNet):
"""
ResNeXt, see https://arxiv.org/abs/1611.05431
Args:
depth (int): network depth, should be 50, 101, 152.
groups (int): group convolution cardinality
group_width (int): width of each group convolution
freeze_at (int): freeze the backbone at which stage
norm_type (str): normalization type, 'bn', 'sync_bn' or 'affine_channel'
freeze_norm (bool): freeze normalization layers
norm_decay (float): weight decay for normalization layer weights
variant (str): ResNet variant, supports 'a', 'b', 'c', 'd' currently
feature_maps (list): index of the stages whose feature maps are returned
dcn_v2_stages (list): index of stages who select deformable conv v2
"""
def __init__(self,
depth=50,
groups=64,
group_width=4,
freeze_at=2,
norm_type='affine_channel',
freeze_norm=True,
norm_decay=True,
variant='a',
feature_maps=[2, 3, 4, 5],
dcn_v2_stages=[],
weight_prefix_name=''):
assert depth in [50, 101, 152], "depth {} should be 50, 101 or 152"
super(ResNeXt, self).__init__(depth, freeze_at, norm_type, freeze_norm,
norm_decay, variant, feature_maps)
self.depth_cfg = {
50: ([3, 4, 6, 3], self.bottleneck),
101: ([3, 4, 23, 3], self.bottleneck),
152: ([3, 8, 36, 3], self.bottleneck)
}
self.stage_filters = [256, 512, 1024, 2048]
self.groups = groups
self.group_width = group_width
self._model_type = 'ResNeXt'
self.dcn_v2_stages = dcn_v2_stages
@register
@serializable
class ResNeXtC5(ResNeXt):
__doc__ = ResNeXt.__doc__
def __init__(self,
depth=50,
groups=64,
group_width=4,
freeze_at=2,
norm_type='affine_channel',
freeze_norm=True,
norm_decay=True,
variant='a',
feature_maps=[5],
weight_prefix_name=''):
super(ResNeXtC5, self).__init__(depth, groups, group_width, freeze_at,
norm_type, freeze_norm, norm_decay,
variant, feature_maps)
self.severed_head = True