fast-reid/fastreid/modeling/heads/reduction_head.py

59 lines
1.9 KiB
Python

# encoding: utf-8
"""
@author: liaoxingyu
@contact: sherlockliao01@gmail.com
"""
from .build import REID_HEADS_REGISTRY
from ..model_utils import weights_init_kaiming
from ...layers import *
@REID_HEADS_REGISTRY.register()
class ReductionHead(nn.Module):
def __init__(self, cfg, in_feat, num_classes, pool_layer=nn.AdaptiveAvgPool2d(1)):
super().__init__()
reduction_dim = cfg.MODEL.HEADS.REDUCTION_DIM
self.pool_layer = nn.Sequential(
pool_layer,
Flatten()
)
self.bottleneck = nn.Sequential(
nn.Linear(in_feat, reduction_dim, bias=False),
NoBiasBatchNorm1d(reduction_dim),
nn.LeakyReLU(0.1),
nn.Dropout(0.5),
)
self.bnneck = NoBiasBatchNorm1d(reduction_dim)
self.bottleneck.apply(weights_init_kaiming)
self.bnneck.apply(weights_init_kaiming)
# identity classification layer
if cfg.MODEL.HEADS.CLS_LAYER == 'linear':
self.classifier = nn.Linear(reduction_dim, num_classes, bias=False)
elif cfg.MODEL.HEADS.CLS_LAYER == 'arcface':
self.classifier = Arcface(cfg, reduction_dim)
elif cfg.MODEL.HEADS.CLS_LAYER == 'circle':
self.classifier = Circle(cfg, reduction_dim)
else:
self.classifier = nn.Linear(reduction_dim, num_classes, bias=False)
def forward(self, features, targets=None):
"""
See :class:`ReIDHeads.forward`.
"""
global_feat = self.pool_layer(features)
global_feat = self.bottleneck(global_feat)
bn_feat = self.bnneck(global_feat)
if not self.training:
return bn_feat
# training
try:
pred_class_logits = self.classifier(bn_feat)
except TypeError:
pred_class_logits = self.classifier(bn_feat, targets)
return pred_class_logits, bn_feat, targets