PulseFocusPlatform/build/lib/ppdet/modeling/heads/fcos_head.py

270 lines
9.9 KiB
Python

# 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 absolute_import
from __future__ import division
from __future__ import print_function
import math
import paddle
import paddle.nn as nn
import paddle.nn.functional as F
from paddle import ParamAttr
from paddle.nn.initializer import Normal, Constant
from ppdet.core.workspace import register
from ppdet.modeling.layers import ConvNormLayer
class ScaleReg(nn.Layer):
"""
Parameter for scaling the regression outputs.
"""
def __init__(self):
super(ScaleReg, self).__init__()
self.scale_reg = self.create_parameter(
shape=[1],
attr=ParamAttr(initializer=Constant(value=1.)),
dtype="float32")
def forward(self, inputs):
out = inputs * self.scale_reg
return out
@register
class FCOSFeat(nn.Layer):
"""
FCOSFeat of FCOS
Args:
feat_in (int): The channel number of input Tensor.
feat_out (int): The channel number of output Tensor.
num_convs (int): The convolution number of the FCOSFeat.
norm_type (str): Normalization type, 'bn'/'sync_bn'/'gn'.
use_dcn (bool): Whether to use dcn in tower or not.
"""
def __init__(self,
feat_in=256,
feat_out=256,
num_convs=4,
norm_type='bn',
use_dcn=False):
super(FCOSFeat, self).__init__()
self.num_convs = num_convs
self.norm_type = norm_type
self.cls_subnet_convs = []
self.reg_subnet_convs = []
for i in range(self.num_convs):
in_c = feat_in if i == 0 else feat_out
cls_conv_name = 'fcos_head_cls_tower_conv_{}'.format(i)
cls_conv = self.add_sublayer(
cls_conv_name,
ConvNormLayer(
ch_in=in_c,
ch_out=feat_out,
filter_size=3,
stride=1,
norm_type=norm_type,
use_dcn=use_dcn,
bias_on=True,
lr_scale=2.))
self.cls_subnet_convs.append(cls_conv)
reg_conv_name = 'fcos_head_reg_tower_conv_{}'.format(i)
reg_conv = self.add_sublayer(
reg_conv_name,
ConvNormLayer(
ch_in=in_c,
ch_out=feat_out,
filter_size=3,
stride=1,
norm_type=norm_type,
use_dcn=use_dcn,
bias_on=True,
lr_scale=2.))
self.reg_subnet_convs.append(reg_conv)
def forward(self, fpn_feat):
cls_feat = fpn_feat
reg_feat = fpn_feat
for i in range(self.num_convs):
cls_feat = F.relu(self.cls_subnet_convs[i](cls_feat))
reg_feat = F.relu(self.reg_subnet_convs[i](reg_feat))
return cls_feat, reg_feat
@register
class FCOSHead(nn.Layer):
"""
FCOSHead
Args:
fcos_feat (object): Instance of 'FCOSFeat'
num_classes (int): Number of classes
fpn_stride (list): The stride of each FPN Layer
prior_prob (float): Used to set the bias init for the class prediction layer
fcos_loss (object): Instance of 'FCOSLoss'
norm_reg_targets (bool): Normalization the regression target if true
centerness_on_reg (bool): The prediction of centerness on regression or clssification branch
"""
__inject__ = ['fcos_feat', 'fcos_loss']
__shared__ = ['num_classes']
def __init__(self,
fcos_feat,
num_classes=80,
fpn_stride=[8, 16, 32, 64, 128],
prior_prob=0.01,
fcos_loss='FCOSLoss',
norm_reg_targets=True,
centerness_on_reg=True):
super(FCOSHead, self).__init__()
self.fcos_feat = fcos_feat
self.num_classes = num_classes
self.fpn_stride = fpn_stride
self.prior_prob = prior_prob
self.fcos_loss = fcos_loss
self.norm_reg_targets = norm_reg_targets
self.centerness_on_reg = centerness_on_reg
conv_cls_name = "fcos_head_cls"
bias_init_value = -math.log((1 - self.prior_prob) / self.prior_prob)
self.fcos_head_cls = self.add_sublayer(
conv_cls_name,
nn.Conv2D(
in_channels=256,
out_channels=self.num_classes,
kernel_size=3,
stride=1,
padding=1,
weight_attr=ParamAttr(
name=conv_cls_name + "_weights",
initializer=Normal(
mean=0., std=0.01)),
bias_attr=ParamAttr(
name=conv_cls_name + "_bias",
initializer=Constant(value=bias_init_value))))
conv_reg_name = "fcos_head_reg"
self.fcos_head_reg = self.add_sublayer(
conv_reg_name,
nn.Conv2D(
in_channels=256,
out_channels=4,
kernel_size=3,
stride=1,
padding=1,
weight_attr=ParamAttr(
name=conv_reg_name + "_weights",
initializer=Normal(
mean=0., std=0.01)),
bias_attr=ParamAttr(
name=conv_reg_name + "_bias",
initializer=Constant(value=0))))
conv_centerness_name = "fcos_head_centerness"
self.fcos_head_centerness = self.add_sublayer(
conv_centerness_name,
nn.Conv2D(
in_channels=256,
out_channels=1,
kernel_size=3,
stride=1,
padding=1,
weight_attr=ParamAttr(
name=conv_centerness_name + "_weights",
initializer=Normal(
mean=0., std=0.01)),
bias_attr=ParamAttr(
name=conv_centerness_name + "_bias",
initializer=Constant(value=0))))
self.scales_regs = []
for i in range(len(self.fpn_stride)):
lvl = int(math.log(int(self.fpn_stride[i]), 2))
feat_name = 'p{}_feat'.format(lvl)
scale_reg = self.add_sublayer(feat_name, ScaleReg())
self.scales_regs.append(scale_reg)
def _compute_locations_by_level(self, fpn_stride, feature):
"""
Compute locations of anchor points of each FPN layer
Args:
fpn_stride (int): The stride of current FPN feature map
feature (Tensor): Tensor of current FPN feature map
Return:
Anchor points locations of current FPN feature map
"""
shape_fm = paddle.shape(feature)
shape_fm.stop_gradient = True
h, w = shape_fm[2], shape_fm[3]
shift_x = paddle.arange(0, w * fpn_stride, fpn_stride)
shift_y = paddle.arange(0, h * fpn_stride, fpn_stride)
shift_x = paddle.unsqueeze(shift_x, axis=0)
shift_y = paddle.unsqueeze(shift_y, axis=1)
shift_x = paddle.expand(shift_x, shape=[h, w])
shift_y = paddle.expand(shift_y, shape=[h, w])
shift_x.stop_gradient = True
shift_y.stop_gradient = True
shift_x = paddle.reshape(shift_x, shape=[-1])
shift_y = paddle.reshape(shift_y, shape=[-1])
location = paddle.stack(
[shift_x, shift_y], axis=-1) + float(fpn_stride) / 2
location.stop_gradient = True
return location
def forward(self, fpn_feats, is_training):
assert len(fpn_feats) == len(
self.fpn_stride
), "The size of fpn_feats is not equal to size of fpn_stride"
cls_logits_list = []
bboxes_reg_list = []
centerness_list = []
for scale_reg, fpn_stride, fpn_feat in zip(self.scales_regs,
self.fpn_stride, fpn_feats):
fcos_cls_feat, fcos_reg_feat = self.fcos_feat(fpn_feat)
cls_logits = self.fcos_head_cls(fcos_cls_feat)
bbox_reg = scale_reg(self.fcos_head_reg(fcos_reg_feat))
if self.centerness_on_reg:
centerness = self.fcos_head_centerness(fcos_reg_feat)
else:
centerness = self.fcos_head_centerness(fcos_cls_feat)
if self.norm_reg_targets:
bbox_reg = F.relu(bbox_reg)
if not is_training:
bbox_reg = bbox_reg * fpn_stride
else:
bbox_reg = paddle.exp(bbox_reg)
cls_logits_list.append(cls_logits)
bboxes_reg_list.append(bbox_reg)
centerness_list.append(centerness)
if not is_training:
locations_list = []
for fpn_stride, feature in zip(self.fpn_stride, fpn_feats):
location = self._compute_locations_by_level(fpn_stride, feature)
locations_list.append(location)
return locations_list, cls_logits_list, bboxes_reg_list, centerness_list
else:
return cls_logits_list, bboxes_reg_list, centerness_list
def get_loss(self, fcos_head_outs, tag_labels, tag_bboxes, tag_centerness):
cls_logits, bboxes_reg, centerness = fcos_head_outs
return self.fcos_loss(cls_logits, bboxes_reg, centerness, tag_labels,
tag_bboxes, tag_centerness)