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

131 lines
4.3 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 collections import OrderedDict
from paddle import fluid
from paddle.fluid.param_attr import ParamAttr
from ppdet.core.workspace import register
__all__ = ['HRFPN']
@register
class HRFPN(object):
"""
HRNet, see https://arxiv.org/abs/1908.07919
Args:
num_chan (int): number of feature channels
pooling_type (str): pooling type of downsampling
share_conv (bool): whethet to share conv for different layers' reduction
spatial_scale (list): feature map scaling factor
"""
def __init__(
self,
num_chan=256,
pooling_type="avg",
share_conv=False,
spatial_scale=[1. / 64, 1. / 32, 1. / 16, 1. / 8, 1. / 4], ):
self.num_chan = num_chan
self.pooling_type = pooling_type
self.share_conv = share_conv
self.spatial_scale = spatial_scale
return
def get_output(self, body_dict):
num_out = len(self.spatial_scale)
body_name_list = list(body_dict.keys())
num_backbone_stages = len(body_name_list)
outs = []
outs.append(body_dict[body_name_list[0]])
# resize
for i in range(1, len(body_dict)):
resized = self.resize_input_tensor(body_dict[body_name_list[i]],
outs[0], 2**i)
outs.append(resized)
# concat
out = fluid.layers.concat(outs, axis=1)
# reduction
out = fluid.layers.conv2d(
input=out,
num_filters=self.num_chan,
filter_size=1,
stride=1,
padding=0,
param_attr=ParamAttr(name='hrfpn_reduction_weights'),
bias_attr=False)
# conv
outs = [out]
for i in range(1, num_out):
outs.append(
self.pooling(
out, size=2**i, stride=2**i,
pooling_type=self.pooling_type))
outputs = []
for i in range(num_out):
conv_name = "shared_fpn_conv" if self.share_conv else "shared_fpn_conv_" + str(
i)
conv = fluid.layers.conv2d(
input=outs[i],
num_filters=self.num_chan,
filter_size=3,
stride=1,
padding=1,
param_attr=ParamAttr(name=conv_name + "_weights"),
bias_attr=False)
outputs.append(conv)
for idx in range(0, num_out - len(body_name_list)):
body_name_list.append("fpn_res5_sum_subsampled_{}x".format(2**(idx +
1)))
outputs = outputs[::-1]
body_name_list = body_name_list[::-1]
res_dict = OrderedDict([(body_name_list[k], outputs[k])
for k in range(len(body_name_list))])
return res_dict, self.spatial_scale
def resize_input_tensor(self, body_input, ref_output, scale):
shape = fluid.layers.shape(ref_output)
shape_hw = fluid.layers.slice(shape, axes=[0], starts=[2], ends=[4])
out_shape_ = shape_hw
out_shape = fluid.layers.cast(out_shape_, dtype='int32')
out_shape.stop_gradient = True
body_output = fluid.layers.resize_bilinear(
body_input, scale=scale, out_shape=out_shape)
return body_output
def pooling(self, input, size, stride, pooling_type):
pool = fluid.layers.pool2d(
input=input,
pool_size=size,
pool_stride=stride,
pool_type=pooling_type)
return pool