fast-reid/fastreid/modeling/meta_arch/mgn.py

269 lines
10 KiB
Python

# encoding: utf-8
"""
@author: liaoxingyu
@contact: sherlockliao01@gmail.com
"""
import copy
import torch
from torch import nn
from fastreid.layers import get_norm
from fastreid.modeling.backbones import build_backbone
from fastreid.modeling.backbones.resnet import Bottleneck
from fastreid.modeling.heads import build_heads
from fastreid.modeling.losses import *
from .build import META_ARCH_REGISTRY
@META_ARCH_REGISTRY.register()
class MGN(nn.Module):
def __init__(self, cfg):
super().__init__()
self._cfg = cfg
assert len(cfg.MODEL.PIXEL_MEAN) == len(cfg.MODEL.PIXEL_STD)
self.register_buffer("pixel_mean", torch.Tensor(cfg.MODEL.PIXEL_MEAN).view(1, -1, 1, 1))
self.register_buffer("pixel_std", torch.Tensor(cfg.MODEL.PIXEL_STD).view(1, -1, 1, 1))
# fmt: off
# backbone
bn_norm = cfg.MODEL.BACKBONE.NORM
with_se = cfg.MODEL.BACKBONE.WITH_SE
# fmt :on
backbone = build_backbone(cfg)
self.backbone = nn.Sequential(
backbone.conv1,
backbone.bn1,
backbone.relu,
backbone.maxpool,
backbone.layer1,
backbone.layer2,
backbone.layer3[0]
)
res_conv4 = nn.Sequential(*backbone.layer3[1:])
res_g_conv5 = backbone.layer4
res_p_conv5 = nn.Sequential(
Bottleneck(1024, 512, bn_norm, False, with_se, downsample=nn.Sequential(
nn.Conv2d(1024, 2048, 1, bias=False), get_norm(bn_norm, 2048))),
Bottleneck(2048, 512, bn_norm, False, with_se),
Bottleneck(2048, 512, bn_norm, False, with_se))
res_p_conv5.load_state_dict(backbone.layer4.state_dict())
# branch1
self.b1 = nn.Sequential(
copy.deepcopy(res_conv4),
copy.deepcopy(res_g_conv5)
)
self.b1_head = build_heads(cfg)
# branch2
self.b2 = nn.Sequential(
copy.deepcopy(res_conv4),
copy.deepcopy(res_p_conv5)
)
self.b2_head = build_heads(cfg)
self.b21_head = build_heads(cfg)
self.b22_head = build_heads(cfg)
# branch3
self.b3 = nn.Sequential(
copy.deepcopy(res_conv4),
copy.deepcopy(res_p_conv5)
)
self.b3_head = build_heads(cfg)
self.b31_head = build_heads(cfg)
self.b32_head = build_heads(cfg)
self.b33_head = build_heads(cfg)
@property
def device(self):
return self.pixel_mean.device
def forward(self, batched_inputs):
images = self.preprocess_image(batched_inputs)
features = self.backbone(images) # (bs, 2048, 16, 8)
# branch1
b1_feat = self.b1(features)
# branch2
b2_feat = self.b2(features)
b21_feat, b22_feat = torch.chunk(b2_feat, 2, dim=2)
# branch3
b3_feat = self.b3(features)
b31_feat, b32_feat, b33_feat = torch.chunk(b3_feat, 3, dim=2)
if self.training:
assert "targets" in batched_inputs, "Person ID annotation are missing in training!"
targets = batched_inputs["targets"].long().to(self.device)
if targets.sum() < 0: targets.zero_()
b1_outputs = self.b1_head(b1_feat, targets)
b2_outputs = self.b2_head(b2_feat, targets)
b21_outputs = self.b21_head(b21_feat, targets)
b22_outputs = self.b22_head(b22_feat, targets)
b3_outputs = self.b3_head(b3_feat, targets)
b31_outputs = self.b31_head(b31_feat, targets)
b32_outputs = self.b32_head(b32_feat, targets)
b33_outputs = self.b33_head(b33_feat, targets)
losses = self.losses(b1_outputs,
b2_outputs, b21_outputs, b22_outputs,
b3_outputs, b31_outputs, b32_outputs, b33_outputs,
targets)
return losses
else:
b1_pool_feat = self.b1_head(b1_feat)
b2_pool_feat = self.b2_head(b2_feat)
b21_pool_feat = self.b21_head(b21_feat)
b22_pool_feat = self.b22_head(b22_feat)
b3_pool_feat = self.b3_head(b3_feat)
b31_pool_feat = self.b31_head(b31_feat)
b32_pool_feat = self.b32_head(b32_feat)
b33_pool_feat = self.b33_head(b33_feat)
pred_feat = torch.cat([b1_pool_feat, b2_pool_feat, b3_pool_feat, b21_pool_feat,
b22_pool_feat, b31_pool_feat, b32_pool_feat, b33_pool_feat], dim=1)
return pred_feat
def preprocess_image(self, batched_inputs):
r"""
Normalize and batch the input images.
"""
if isinstance(batched_inputs, dict):
images = batched_inputs["images"].to(self.device)
elif isinstance(batched_inputs, torch.Tensor):
images = batched_inputs.to(self.device)
else:
raise TypeError("batched_inputs must be dict or torch.Tensor, but get {}".format(type(batched_inputs)))
images.sub_(self.pixel_mean).div_(self.pixel_std)
return images
def losses(self,
b1_outputs,
b2_outputs, b21_outputs, b22_outputs,
b3_outputs, b31_outputs, b32_outputs, b33_outputs, gt_labels):
# model predictions
# fmt: off
pred_class_logits = b1_outputs['pred_class_logits'].detach()
b1_logits = b1_outputs['cls_outputs']
b2_logits = b2_outputs['cls_outputs']
b21_logits = b21_outputs['cls_outputs']
b22_logits = b22_outputs['cls_outputs']
b3_logits = b3_outputs['cls_outputs']
b31_logits = b31_outputs['cls_outputs']
b32_logits = b32_outputs['cls_outputs']
b33_logits = b33_outputs['cls_outputs']
b1_pool_feat = b1_outputs['features']
b2_pool_feat = b2_outputs['features']
b3_pool_feat = b3_outputs['features']
b21_pool_feat = b21_outputs['features']
b22_pool_feat = b22_outputs['features']
b31_pool_feat = b31_outputs['features']
b32_pool_feat = b32_outputs['features']
b33_pool_feat = b33_outputs['features']
# fmt: on
# Log prediction accuracy
log_accuracy(pred_class_logits, gt_labels)
b22_pool_feat = torch.cat((b21_pool_feat, b22_pool_feat), dim=1)
b33_pool_feat = torch.cat((b31_pool_feat, b32_pool_feat, b33_pool_feat), dim=1)
loss_dict = {}
loss_names = self._cfg.MODEL.LOSSES.NAME
if "CrossEntropyLoss" in loss_names:
loss_dict['loss_cls_b1'] = cross_entropy_loss(
b1_logits,
gt_labels,
self._cfg.MODEL.LOSSES.CE.EPSILON,
self._cfg.MODEL.LOSSES.CE.ALPHA,
) * self._cfg.MODEL.LOSSES.CE.SCALE * 0.125
loss_dict['loss_cls_b2'] = cross_entropy_loss(
b2_logits,
gt_labels,
self._cfg.MODEL.LOSSES.CE.EPSILON,
self._cfg.MODEL.LOSSES.CE.ALPHA,
) * self._cfg.MODEL.LOSSES.CE.SCALE * 0.125
loss_dict['loss_cls_b21'] = cross_entropy_loss(
b21_logits,
gt_labels,
self._cfg.MODEL.LOSSES.CE.EPSILON,
self._cfg.MODEL.LOSSES.CE.ALPHA,
) * self._cfg.MODEL.LOSSES.CE.SCALE * 0.125
loss_dict['loss_cls_b22'] = cross_entropy_loss(
b22_logits,
gt_labels,
self._cfg.MODEL.LOSSES.CE.EPSILON,
self._cfg.MODEL.LOSSES.CE.ALPHA,
) * self._cfg.MODEL.LOSSES.CE.SCALE * 0.125
loss_dict['loss_cls_b3'] = cross_entropy_loss(
b3_logits,
gt_labels,
self._cfg.MODEL.LOSSES.CE.EPSILON,
self._cfg.MODEL.LOSSES.CE.ALPHA,
) * self._cfg.MODEL.LOSSES.CE.SCALE * 0.125
loss_dict['loss_cls_b31'] = cross_entropy_loss(
b31_logits,
gt_labels,
self._cfg.MODEL.LOSSES.CE.EPSILON,
self._cfg.MODEL.LOSSES.CE.ALPHA,
) * self._cfg.MODEL.LOSSES.CE.SCALE * 0.125
loss_dict['loss_cls_b32'] = cross_entropy_loss(
b32_logits,
gt_labels,
self._cfg.MODEL.LOSSES.CE.EPSILON,
self._cfg.MODEL.LOSSES.CE.ALPHA,
) * self._cfg.MODEL.LOSSES.CE.SCALE * 0.125
loss_dict['loss_cls_b33'] = cross_entropy_loss(
b33_logits,
gt_labels,
self._cfg.MODEL.LOSSES.CE.EPSILON,
self._cfg.MODEL.LOSSES.CE.ALPHA,
) * self._cfg.MODEL.LOSSES.CE.SCALE * 0.125
if "TripletLoss" in loss_names:
loss_dict['loss_triplet_b1'] = triplet_loss(
b1_pool_feat,
gt_labels,
self._cfg.MODEL.LOSSES.TRI.MARGIN,
self._cfg.MODEL.LOSSES.TRI.NORM_FEAT,
self._cfg.MODEL.LOSSES.TRI.HARD_MINING,
) * self._cfg.MODEL.LOSSES.TRI.SCALE * 0.2
loss_dict['loss_triplet_b2'] = triplet_loss(
b2_pool_feat,
gt_labels,
self._cfg.MODEL.LOSSES.TRI.MARGIN,
self._cfg.MODEL.LOSSES.TRI.NORM_FEAT,
self._cfg.MODEL.LOSSES.TRI.HARD_MINING,
) * self._cfg.MODEL.LOSSES.TRI.SCALE * 0.2
loss_dict['loss_triplet_b3'] = triplet_loss(
b3_pool_feat,
gt_labels,
self._cfg.MODEL.LOSSES.TRI.MARGIN,
self._cfg.MODEL.LOSSES.TRI.NORM_FEAT,
self._cfg.MODEL.LOSSES.TRI.HARD_MINING,
) * self._cfg.MODEL.LOSSES.TRI.SCALE * 0.2
loss_dict['loss_triplet_b22'] = triplet_loss(
b22_pool_feat,
gt_labels,
self._cfg.MODEL.LOSSES.TRI.MARGIN,
self._cfg.MODEL.LOSSES.TRI.NORM_FEAT,
self._cfg.MODEL.LOSSES.TRI.HARD_MINING,
) * self._cfg.MODEL.LOSSES.TRI.SCALE * 0.2
loss_dict['loss_triplet_b33'] = triplet_loss(
b33_pool_feat,
gt_labels,
self._cfg.MODEL.LOSSES.TRI.MARGIN,
self._cfg.MODEL.LOSSES.TRI.NORM_FEAT,
self._cfg.MODEL.LOSSES.TRI.HARD_MINING,
) * self._cfg.MODEL.LOSSES.TRI.SCALE * 0.2
return loss_dict